GL1800 cooling fan wiring modification kit


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2manywings
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GL1800 cooling fan wiring modification kit

Post by 2manywings » Wed Sep 19, 2018 11:43 am



I've got a 2003 GL1800 with the dreaded engine temp. issue. I've been told that there is someone out there that developed a wiring harness to reverse the fan motors and add a switch to manually turn the fans on (or something to that effect). I've searched the web, but have been unable to find any info. If anyone out there has any info, I'd be very thankful.



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Re: GL1800 cooling fan wiring modification kit

Post by DaveO430 » Wed Sep 19, 2018 11:57 am

That will only help if your temperature problem is when running 15 to 20 MPH. Is that your issue? You don't need a "kit" to do it anyway, just reverse the wires in the fan connector and if the fans are coming on at a little over 1/2 on the gauge why would you need a manual switch?

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Re: GL1800 cooling fan wiring modification kit

Post by 2manywings » Wed Sep 19, 2018 12:56 pm

The issue is on an '03 that recently got triked. He's never had issues before (he's owned this for several years), but now that it's triked, I think it's working a bit harder. And he was pulling his camping trailer when this happened. The fans are currently working the way that they were designed (will run when needed up to about 15mph). My thought was that at speeds above that (15-20 mph) and reversing the air flow direction, if you could turn the fans on manually, you could pull a little more fresh air through the radiators if the temp was creeping up. I know that Honda had a recall on some of the early 1800s for this problem which involved a new ECU. The owner at that time did not take advantage of that and it expired in 2006. But according to my local Honda service manager, that basically just changed the reading on the gauge. I know that there are a lot of variables in the equation, but I'm just hoping to give him a way to help the bike out when the conditions get extreme.

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Re: GL1800 cooling fan wiring modification kit

Post by MikeB » Wed Sep 19, 2018 6:17 pm

I too have a 2003 where the heat rises when I wish it would not. I've decided that one of these days I will add a switch to the fan relay circuit to turn on the fan. It is a simple modification, it is just a matter of deciding where I want to put the switch and
having an alert system of some sort to let me know it is being run manually.

I have read that reversing the fan direction is not the answer. The reason given was that fan blades are designed to push air in a specific direction. Reversing the fan direction of rotation by reversing fan motor direction would make then inefficient. Not being an engineer, I cannot confirm or deny this.

The ECM controls when the fans come on. It supplies a ground to the fan relay (I believe). Since the fans come on when the bike speed is below 15 mph, what I would wish for is an ECM that would turn on the fans ANY time it is needed in first and second gear.

That way, the fans will not be fighting the inrush of air from forward motion since you will probably not be exceeding 35 mph in 1st or 2nd. That would work I believe but I'm not holding my breath for anything like that to happen. So, I will make the time to figure out where to put the switch and get it a hooked up.
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Re: GL1800 cooling fan wiring modification kit

Post by Techdude2000 » Thu Sep 20, 2018 8:17 am

If you reverse the wires on the fans, you will have to flip the blades as well due to them having a contour that is inefficient if run backward. This whole deal only helps if you are doing 16-20 mph with a tail wind. There used to be a company that sold a kit that had new fan blades and a near plug and play setup, but I don’t think they are around anymore. You can flip the blades over, but it takes a little trimming on the blade hub to make them fit correctly on the motor shafts and shimming of the shroud to not hit the radiators. It can be done and does work, but I don’t have any pictures or guides to it. It was shown in a DYI on another BB board years ago. Here you go, just found all you need to know about this: http://goldwing.eurekaboy.com/fanreversal.htm

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Re: GL1800 cooling fan wiring modification kit

Post by Kurt J » Mon Sep 24, 2018 9:30 am

All most every bike I have had I have done the fan switch tech tip.
All you need is some wire,clips and a switch (lighted or not.
Just locate the sending unit in the rad. Look to see if it is 2 wire or one.
If it is a one wire then run one side of your switch to the sending unit wire. Run the other side of the switch to a ground on the frame. Turn the ign on and the switch and the fan will run until you turn it off.
If it is a 2 wire connect the wires from each side of the switch. Turn the ign on and the fan will run until you turn the switch off.

All your doing is grounding the sending unit before it does it it self.

I use the switch when in very slow traffic and heat conditions.

BTW...with the switch off the bike fan will still work as needed when the bike kicks it on and off. Also this does not reverse the fan.
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Re: GL1800 cooling fan wiring modification kit

Post by MikeB » Mon Sep 24, 2018 10:39 am

Kurt J wrote:
Mon Sep 24, 2018 9:30 am
All most every bike I have had I have done the fan switch tech tip.
All you need is some wire,clips and a switch (lighted or not.
Just locate the sending unit in the rad. Look to see if it is 2 wire or one.
If it is a one wire then run one side of your switch to the sending unit wire. Run the other side of the switch to a ground on the frame. Turn the ign on and the switch and the fan will run until you turn it off.
If it is a 2 wire connect the wires from each side of the switch. Turn the ign on and the fan will run until you turn the switch off.

All your doing is grounding the sending unit before it does it it self.

I use the switch when in very slow traffic and heat conditions.

BTW...with the switch off the bike fan will still work as needed when the bike kicks it on and off. Also this does not reverse the fan.
Hi Kurt. What "fan switch tech tip" is that you are referring to? I have not seen a fan switch tech tip. Where can I find that?

As far as I know, the easiest way to manually turn the fans on is to install a switch to supply a ground to the fan control relay.


If there is another, possibly easier and improved method, I'd like to know about it.

Also, where did you mount the switch on the Gold Wings you have modified? Possibly a handlebar switch box?
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Re: GL1800 cooling fan wiring modification kit

Post by DaveO430 » Mon Sep 24, 2018 11:55 am

OK, if the fans are working like they are supposed to what is the reason behind installing a manual switch? On is on, they don't get any more on. I have on mine had it get a little above normal temperature when going between 15 & 20 mph in hot weather. The fans turn off at about 20, if I could get above 20 and the fans cut off it would cool down because the fans were not fighting the air coming in the front. Or if I stayed below 15 the fans would keep it cool. Having a switch to turn the fans on would not help anything, probably even make it worse if they stayed on above 20mph, unless you did the reversing mod.

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Re: GL1800 cooling fan wiring modification kit

Post by Techdude2000 » Mon Sep 24, 2018 1:01 pm

DaveO430 wrote:
Mon Sep 24, 2018 11:55 am
OK, if the fans are working like they are supposed to what is the reason behind installing a manual switch? On is on, they don't get any more on. I have on mine had it get a little above normal temperature when going between 15 & 20 mph in hot weather. The fans turn off at about 20, if I could get above 20 and the fans cut off it would cool down because the fans were not fighting the air coming in the front. Or if I stayed below 15 the fans would keep it cool. Having a switch to turn the fans on would not help anything, probably even make it worse if they stayed on above 20mph, unless you did the reversing mod.
I agree, the manual switch is only helpful if you reverse the fan blades and polarity and have the fans help the incoming air when you are just above the ECM’s turn off speed. If we look at Eureka Boys page that I posted a link to above, near the bottom of it there’s another link that explains his air flow testing with the fans not flipped. Just reversing the polarity will cause the system to lose a lot of air movement and actually cause the bike to heat up even quicker. If a switch is used, the polarity and the blades must be flipped or the whole system gets worse. And even this mod is only helpful for about 10 mph above the ECM cutoff of approx. 15 mph, above that and the fans will start hindering the incoming airflow.

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Re: GL1800 cooling fan wiring modification kit

Post by MikeB » Mon Sep 24, 2018 1:17 pm

DaveO430 wrote:
Mon Sep 24, 2018 11:55 am
OK, if the fans are working like they are supposed to what is the reason behind installing a manual switch? On is on, they don't get any more on. I have on mine had it get a little above normal temperature when going between 15 & 20 mph in hot weather. The fans turn off at about 20, if I could get above 20 and the fans cut off it would cool down because the fans were not fighting the air coming in the front. Or if I stayed below 15 the fans would keep it cool. Having a switch to turn the fans on would not help anything, probably even make it worse if they stayed on above 20mph, unless you did the reversing mod.
On is on, up until 15 mph. Then they are off.

From your profile, I see you have a 2010. The radiators installed in 2006 and later GL1800's are larger than 2001 through 2005. You do not have the overheating issues that the 2001 through 2005 have.

To explain the reason for the fan switch I have to say that the fans turn off at approximately 15 mph. Between 15 and 25 mph it has been my experience that there is not enough air going through the radiators to cool it down when the ambient temps are 80 degrees Fahrenheit and above. Especially if you are in stop and go traffic, such as a long steep up grade with a line of cars in front of you that is behind a slow moving truck. The stop periods are not long enough to cool the coolant and the go periods are not long enough to provide sufficient cooling air through the radiators.

Thus the desire to allow the fans to run until about 25 mph.
MikeB
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Re: GL1800 cooling fan wiring modification kit

Post by Kurt J » Mon Sep 24, 2018 2:48 pm

MikeB wrote:
Mon Sep 24, 2018 10:39 am
Kurt J wrote:
Mon Sep 24, 2018 9:30 am
All most every bike I have had I have done the fan switch tech tip.
All you need is some wire,clips and a switch (lighted or not.
Just locate the sending unit in the rad. Look to see if it is 2 wire or one.
If it is a one wire then run one side of your switch to the sending unit wire. Run the other side of the switch to a ground on the frame. Turn the ign on and the switch and the fan will run until you turn it off.
If it is a 2 wire connect the wires from each side of the switch. Turn the ign on and the fan will run until you turn the switch off.

All your doing is grounding the sending unit before it does it it self.

I use the switch when in very slow traffic and heat conditions.

BTW...with the switch off the bike fan will still work as needed when the bike kicks it on and off. Also this does not reverse the fan.
Hi Kurt. What "fan switch tech tip" is that you are referring to? I have not seen a fan switch tech tip. Where can I find that?

As far as I know, the easiest way to manually turn the fans on is to install a switch to supply a ground to the fan control relay.
Fan Ckt.jpg
If there is another, possibly easier and improved method, I'd like to know about it.

Also, where did you mount the switch on the Gold Wings you have modified? Possibly a handlebar switch box?
You can use the relays if you chose too....does the same thing. As I said before this is only good to use when your almost at idle speed and it is hot out....or stop and go traffic. Other than that the bike can take care of it self.
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Re: GL1800 cooling fan wiring modification kit

Post by Big Blue UK » Mon Sep 24, 2018 6:24 pm

I did the fan mod on mine, massive difference, especially on parades, and the fans are not pushing the air out the front against the natural flow of air. On 2 occasions during a parade my temp started to climb more than I was comfortable with, and had to pull over for the fans to kick in. Being able to turn the fans on is great, peace of mind too. I highly recommend it, if you do parades that is. I do 6 a year.
I was also towing trailer with pillion.
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Re: GL1800 cooling fan wiring modification kit

Post by RThill4355 » Wed Oct 03, 2018 8:59 am

Thanks to all for your responses. 2 many wings is the person working on the 03 trike, which is mine. To add to the information, before 03 was triked, I was taking a GWRRA ARC course in very hot weather and the bike (then- 2 wheels) was experiencing overheating issues, plus I was smelling coolant, but no visible leaks, no puddles. Before that the bike always ran normal (needle just below or touching the center mark on the temp gauge). After being trikes ran a bit at or above the middle mark on the temp gauge. Took a ride on another warm day and was stuck in stop and go traffic and the needle almost hit the red warning line on the gauge, (no trailer-just the trike), stopped and let trike cool down, then checked the overflow tank and the coolant barely touched the dipstick. Added maybe 1 ounce of Honda coolant, and on the way home, ran the mark above center on gauge. Then on the way home after an outing with camper trailer, ran very hot, almost touching the red mark, let it cool down again, then made it home. I love the trike but need to trust it to get me home. 2 many wings ( great Honda tech) has trike now and has written this forum, help us out. Also, no foam or milky substance in oil or dipstick. Sorry this is so long, just wanted to add all details.

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Re: GL1800 cooling fan wiring modification kit

Post by Techdude2000 » Wed Oct 03, 2018 10:43 am

A wing triked or not should not run hot while driving above 25 mph. You might have something else in the cooling system causing this, blocked radiator, bad thermostat, etc... If there is something else going on, then the fan reversal won’t give you the results you’re looking for.

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Re: GL1800 cooling fan wiring modification kit

Post by dkdc12 » Wed Oct 03, 2018 4:50 pm

Hey, I was reading about the cooling issues and fan “tinkering”. What about that “water wetter” additive, known by various names. In my old bike GL1200 I is used it and my temp gauge even registered at a lower temp. Just a thought.
JEAN@stevie

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Re: GL1800 cooling fan wiring modification kit

Post by DaveO430 » Wed Oct 03, 2018 5:44 pm

MikeB wrote:
Mon Sep 24, 2018 1:17 pm
DaveO430 wrote:
Mon Sep 24, 2018 11:55 am
OK, if the fans are working like they are supposed to what is the reason behind installing a manual switch? On is on, they don't get any more on. I have on mine had it get a little above normal temperature when going between 15 & 20 mph in hot weather. The fans turn off at about 20, if I could get above 20 and the fans cut off it would cool down because the fans were not fighting the air coming in the front. Or if I stayed below 15 the fans would keep it cool. Having a switch to turn the fans on would not help anything, probably even make it worse if they stayed on above 20mph, unless you did the reversing mod.
On is on, up until 15 mph. Then they are off.

From your profile, I see you have a 2010. The radiators installed in 2006 and later GL1800's are larger than 2001 through 2005. You do not have the overheating issues that the 2001 through 2005 have.

To explain the reason for the fan switch I have to say that the fans turn off at approximately 15 mph. Between 15 and 25 mph it has been my experience that there is not enough air going through the radiators to cool it down when the ambient temps are 80 degrees Fahrenheit and above. Especially if you are in stop and go traffic, such as a long steep up grade with a line of cars in front of you that is behind a slow moving truck. The stop periods are not long enough to cool the coolant and the go periods are not long enough to provide sufficient cooling air through the radiators.

Thus the desire to allow the fans to run until about 25 mph.
I wish they had left the fan shut off at 15mph. On my 08 and '10 they run until about 20mph, which is the only time they ever heated up, the fans fighting the incoming air. As I said before, at below 15 with them running, or at 20 when they shut off it would cool down quickly.

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Re: GL1800 cooling fan wiring modification kit

Post by 2manywings » Wed Oct 03, 2018 8:11 pm

I don't know why Mother Honda had to screw with a system that worked just fine for 25 years with no issues. I'd like to know if it's feasible to wire up an 1800 to operate in the same manner as the previous models. I'd think that if the thermal switch operated in the same heat ranges, the fans come on upon temp rise and cycle off when the temp drops, and reverse the blades and fan motor rotation. What's so hard about that? Just trying to find a sensible solution. Any thoughts?

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Re: GL1800 cooling fan wiring modification kit

Post by DaveO430 » Sat Oct 06, 2018 6:34 pm

2manywings wrote:
Wed Oct 03, 2018 8:11 pm
I don't know why Mother Honda had to screw with a system that worked just fine for 25 years with no issues. I'd like to know if it's feasible to wire up an 1800 to operate in the same manner as the previous models. I'd think that if the thermal switch operated in the same heat ranges, the fans come on upon temp rise and cycle off when the temp drops, and reverse the blades and fan motor rotation. What's so hard about that? Just trying to find a sensible solution. Any thoughts?
There is no fan switch, they are operated by the ECM. I think they didn't test the reversed fans in the real world, sounds good on paper, to some engineer.

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Re: GL1800 cooling fan wiring modification kit

Post by MikeB » Sat Oct 06, 2018 11:21 pm

2manywings wrote:
Wed Oct 03, 2018 8:11 pm
I don't know why Mother Honda had to screw with a system that worked just fine for 25 years with no issues. I'd like to know if it's feasible to wire up an 1800 to operate in the same manner as the previous models. I'd think that if the thermal switch operated in the same heat ranges, the fans come on upon temp rise and cycle off when the temp drops, and reverse the blades and fan motor rotation. What's so hard about that? Just trying to find a sensible solution. Any thoughts?
The redesign of the Gold Wing in 2001 makes it impossible to make the cooling system operate like its predecessors.

The GL1800 radiators are mounted lengthwise, front to rear, unlike the GL1500 and earlier which were mounted in the front from left to right. That arrangement made it easy for the radiators to be cooled during forward motion from ram air as well as being cooled by fans that exhausted the cooling air flow to the sides.

With the GL1800 radiators mounted on the sides and the fans sucking air through them and exhausting forward, there is just no way to make it cool like its predecessors. The 2001 through the 2005 radiators were just too small for what the typical rider could subject their bike to.

In 2006, Honda installed larger radiators and that helped considerably. I do not know what else may have been done to the cooling system but from 2006 on the GL1800 does not suffer from the same heat prostration that the earlier GL1800's did.

Eureka Boy's fix is the only real fix that I can think of that would work on the 2003 through 2005 wings where you would not have a repeat of the overheat issue popping up again. Other than doing that, about all you can do is pull off to the side of the road and let the engine cool down by letting the fans run. I have had to do that several times.
MikeB
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Re: GL1800 cooling fan wiring modification kit

Post by RThill4355 » Fri Nov 16, 2018 10:01 am

Ok, now that it is too cold to ride here, I wish to add a bit more to the problem of my "03 Wing overheating issue. I noticed that on Xpressway riding, under 70 mph, no problems, temp gauge stayed in the middle like it has always done both 2 wheel and now triked, however, above 70 mph,(now with trike kit) needle starts to rise until it almost reaches the red mark (no trailer, no co-rider). I would think that at that speed, natural airflow would solve the problem. My thoughts, collapsing coolant hose, or cavitating water pump impeller (all are original 15 years old), thermostat sticking partially open, or radiator cap just plain worn out. I plan on several long trips this summer, with co-rider and trailer, so my thoughts. Take off tupperware only 1 time, replace ALL hoses, water pump, thermostat, and radiator cap. I know this is expensive, but each time plastic has to come off to try another fix is also expensive. I like the trike and don't want to have to sell (at a loss) and trike another bike or buy another trike. I know this may be extreme, but getting stuck on the side of the road is also frustrating and extreme. 2 many wings has done a lot of things to try to help, blowing out radiators, cleaning cooling system and replacing coolant. I am not sure rewiring fans is the real solution. Any thoughts will be appreciated. Sorry to be so long winded.

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Re: GL1800 cooling fan wiring modification kit

Post by AZgl1800 » Fri Nov 16, 2018 10:12 am

I have an '02 and have ridden it on the toll roads at 85+ for hours on end pulling the trailer in my Avatar ( a Square Box ), and the temp gauge never got above the middle of the scale....

Certainly never even close to the red line.

I suspicion, as you do, some physical problem in the cooling system.

In fact, it has only approached the Red Line once, I got stuck in bumper to bumper traffic at a Construction Site as 2 miles of cars made their way through, in near 100°F temps.... even that didn't bother me, because the fans just cycled On/Off... as long as that happens, the engine is NOT in distress.
~John

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Re: GL1800 cooling fan wiring modification kit

Post by Techdude2000 » Fri Nov 16, 2018 4:32 pm

RThill4355 wrote:
Fri Nov 16, 2018 10:01 am
Ok, now that it is too cold to ride here, I wish to add a bit more to the problem of my "03 Wing overheating issue. I noticed that on Xpressway riding, under 70 mph, no problems, temp gauge stayed in the middle like it has always done both 2 wheel and now triked, however, above 70 mph,(now with trike kit) needle starts to rise until it almost reaches the red mark (no trailer, no co-rider). I would think that at that speed, natural airflow would solve the problem. My thoughts, collapsing coolant hose, or cavitating water pump impeller (all are original 15 years old), thermostat sticking partially open, or radiator cap just plain worn out. I plan on several long trips this summer, with co-rider and trailer, so my thoughts. Take off tupperware only 1 time, replace ALL hoses, water pump, thermostat, and radiator cap. I know this is expensive, but each time plastic has to come off to try another fix is also expensive. I like the trike and don't want to have to sell (at a loss) and trike another bike or buy another trike. I know this may be extreme, but getting stuck on the side of the road is also frustrating and extreme. 2 many wings has done a lot of things to try to help, blowing out radiators, cleaning cooling system and replacing coolant. I am not sure rewiring fans is the real solution. Any thoughts will be appreciated. Sorry to be so long winded.
If its getting hot while on the highway, there’s a problem with it that the fan mod can’t fix. I’m betting your thermostat is not opening completely. Faulty thermostats have been found many times before on the 1800. The new pump comes with a new thermostat already installed in it. Good luck and keep us posted.

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Re: GL1800 cooling fan wiring modification kit

Post by themainviking » Sat Nov 17, 2018 7:31 am

Just an off the wall question. Have you been faithful about changing your coolant? Your bike is 15 years old, and if it has the original or near original coolant in it, this could create the problems you are experiencing due to the coolants breakdown. When coolant breaks down, it becomes sticky, which could result in a thermostat not opening or closing properly, and old coolant affects hoses by softening them. Sticky coolant can reduce water passages in radiators as well.
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Re: GL1800 cooling fan wiring modification kit

Post by 2manywings » Sat Nov 17, 2018 8:42 am

The last things that were done to the bike are a complete system flush with a commercial cooling system cleaner, then filled with fresh coolant. Also blew a fair amount of dirt and road crud out of the radiator, and verified that both fans were indeed working properly. At that point, the weather here in Michigan turned much cooler, so we're not sure how much effect those changes have made. The next course of action will be to physically check the radiator cap, thermostat, hoses, and water pump. Reversing the fans is questionable, because no matter what, they're not going to come on at highway speeds anyway (by design). we'll keep everyone posted.



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