Neutral Light Won't TURN OFF!

[XJSRider]

Everyone seems to have a problem where the neutral light won't turn on.

Well mine won't shut off! It stays lit in every gear. It gets a touch brighter when actually in neutral. Maybe a bad ground somewhere?

I had just finished installing the shifter brace and went for a ride. After a few miles I went to stop for gas, hit a bump when going into the station, heard a rattle... like a screw or something falling. Maybe something in the road. When I went to start the bike after filling up it pulled forward! Neutral light was on but bike was in gear. It had just started doing this, it worked fine until this point.

Can some of the electrical wizards here give me some clues where to start looking? Man, I just got it all buttoned up and polished.

[AZgl1800]

the Neutral switch provides a source to Ground.

So, if the light is staying lit up, then you have a Ground somewhere that you don't want.

First, unplug the Neutral Switch to see if the light goes out. That will isolate the switch from the problem.

Obviously, if it stays lit up, you are going to have to trace the wire from the switch to the light and find the short to ground.

it is probably 30 years worth of dirt mixed in with some metallic crap.

[XJSRider]

John when you suggest unplugging it to see if the light goes out... are you talking about the switch by the reverse lever, or the one at front of engine?

[AZgl1800]

John when you suggest unplugging it to see if the light goes out... are you talking about the switch by the reverse lever, or the one at front of engine?

There is a switch that is activated by the Shift Lever, sorry, I don't know the location of that one.

it has been way too many years since I had a 1500

[XJSRider]

Can anyone tell me where the neutral switch is?? I see references to it in the shop manual wiring diagrams but no location and it isn’t in the index.

[DenverWinger]

If the neutral light is a tad brighter when actually in neutral that suggests the neutral switch is working correctly, but you have some other unwanted ground path in the circuit. On the older wings it was usually a bad diode. There's a diode pack in the 1500 that has some of the neutral light circuitry running thru it, too, but that isn't necessarily the cause of your problem.

Too early to study schematics yet, more coffee required....

[XJSRider]

DW I'm sipping on some myself! Got a couple hours this morning to before we hit the road for the day hopefully it is something dumb...

I think you are right about the ground somewhere in the circuit vs switch not working. My OD light works fine so that also supports your theory.

I wish I was better at reading the schematics. I'm getting a lot of practice working on this bike though so maybe someday.

I checked the thread on "adding a gear indicator" to try to get some hints but no real luck... maybe I need the 2nd cup then read it again.

[DenverWinger]

Try this before you head out - Put bike in gear, side stand up, don't use the clutch, and bump the starter. Be prepared for it to jump forward, and maybe actually start and take off, but it might not. Report if the starter engages. It probably will. Try same with sidestand down. It probably won't. These results may help trace where the short is.

[XJSRider]

Mr. Mark,

Some interesting results here. Bike functioned as you guessed....

In gear, sidestand up, no clutch, click starter rear wheel starts to turn.
In gear, sidestand down, no clutch, click starter nothing.

The interesting thing was that the neutral light works as it should with the sidestand down!

[DenverWinger]

Okay - The unwanted ground is thru the "Sidestand Up" circuit - That narrows it down some.

One more cuppa coffee and I'll dig into schematics.

[bellboy40]

Here is a document that might be helpful when trying to diagnose a problem with the neutral light circuit. The ground from the neutral switch takes an interesting route to get to the ground side of the neutral lamp.
This document was prepared by Dbohrer over on the Goldwingfacts board.

Neutral Light Circuit.txt

Neutral light circuit

(2.93 KiB) Downloaded 275 times

[DenverWinger]

OK - enough coffee, I got out the "Spaghetti Diagrams". We've established there's a short between the "sidestand up" circuit and the "neutral" circuit.

Sidestand switch only provides ground to the sidestand light when it is down. When it is up, the only places the sidestand switch is supposed to provide ground to is the clutch switch so you can start in gear using clutch, and the reverse control unit on the GRN/WHT wire. This GRN/WHT wire doesn't go anyplace else. Since the starter works in-gear without clutch, that part of the circuit is out-of-play and it appears there's a short somewhere into the neutral circuit's LT-GRN/RED from this GRN/WHT wire. The GRN/WHT wire doesn't go into the Diode pack anywhere so the diodes are likely OK. The neutral bulb LT-GRN wire only gets ground thru a diode into the LT-GRN/RED neutral wire. A short to the sidestand switch wire into the neutral bulb wire would make the bulb misbehave but the bike wouldn't start in gear without clutch unless the diode was shorted too.

The GRN/WHT wire from the sidestand goes to Reverse Control Unit on pin 10 and the LT-GRN/RED neutral switch wire goes to Reverse Control Unit on pin 8. Possible there's a short in that area.

[XJSRider]

Also when shifting to reverse the light goes out.

[XJSRider]

DW- what diagram are you looking at? I have the FSM with the electrical addendumn. Not sure what pin numbers you are refering to. Thanks for the help.

[DenverWinger]

I'm looking at the GL1500 color diagram provided by Erdeniz Umman. It's on the site here somewhere. Per that diagram I'm referring to pins 8 and 10 of the 14 pin white connector on the reverse control unit.

[ct1500]

You need to narrow down the possible short to ground path and the easiest and most efficient way to do that with no guess work is at the wire connectors. I would start at the 22P red under the seat due to easy access and is about midway in the wiring scheme. Locate the LtGrn/Red wire on the forward side of connector and with appropriate pin extractor tool remove that wire from connector leaving connector intact. With transmission in gear turn key ON and note if light is now out. If still lit now locate the Lt Grn wire on forward side of connector and remove that and turn key back ON and if still lit you are then on your way to pin-point the problem at the next easiest access connector. If light goes out after Lt Grn wire removal then onto the diode connector at the rear. Usual suspect after a reassemble would be a pinched or shorted wire by a screw/bolt etc.

[XJSRider]

I removed the light green / red wire from the front of C32 (red 22p connector under seat) and neutral light went off, even in neutral.

If I understand this correctly that means that there is NOT a short to ground from C32 all the way back to the Neutral light...

Based on the wiring diagram linked a couple posts back, I must be shorting somewhere between C32 and the neutral switch. It looks like there is only one connection between C32 and the neutral switch, C59 (black 6p) which looks to be above the right side fan based on my manual.

Does this sound right??? This electrical newb appreciates the help.

Doesn't seem to explain why neutral works when the side stand is down... maybe I'm backwards and this shows C32-neutral switch is GOOD, not Bad?

[DenverWinger]

Funny thing is the bulb behaves normally if the side stand is down. With side stand up can start in gear without clutch. But not when it's down. So has to be a short where the "sidestand up" circuit is providing ground to the neutral circuit. But only when the side stand is up.

[XJSRider]

I don't think it can be the light green red wire going to pin 8 on the reverse control unit because the light went out when I removed the front side light green/red from C32.

Would love to rule out pin 10 green white because my manual tells me that reverse control unit is "below rear of trunk" but looks like side of bike behind saddle bag based on the pic.

I have been in and out of the front of the bike a bunch of times, and I remember bending those connectors above the right side fan quite a bit. Based on the wiring diagram it really looks like my problem should be between C32 and Neutral switch on light green/red wire but I can't ignore the side stand "fixing" the short to ground.

The problem just started after the shift brace but maybe like CT1500 suggested something has been pinched and coincidentally just wore through

[ct1500]

Sounds good going to the next connector above the fan. You will then go to the ignition section of manual testing each switch wire continuity to rule in or out the switch. Note there is a splice in the neutral wire which does not show in start/reverse section and goes to the ECM. And is why the diagrams leave much to be desired.

[XJSRider]

CT:
I see that neutral wire splice you are talking about. I guess you really need to look at all the wiring diagrams as they seem to include/exclude different components based on the name of the drawing. Wow the colored version is FOR SURE way easier to read. I printed them off at work in color at 11x17 to add to my manual. Tonight I will rip off all the plastic and hopefully find the short at that connector.

I really admire all the engineering in this motorcycle but it is without a doubt the most complicated 2 wheel vehicle I've ever worked on (Only had about 8 bikes, but still). Really incredible stuff especially considering it is all late 80s tech.

[XJSRider]

Here is my sad and pathetic update: I was unable to determine why the light stays on.

For those of you following along at home, from wiring diagram link a few posts back (Lights and Switches 94 ASP), Pulling the light green / red wire from the front side of the Big C32 red connector caused the neutral light to go out. As John pointed out, the Neutral light is hot and all the wiring is providing a path to ground so electricity can flow and the light can... light.

By pulling the front side Light Green/Red wire, and having the neutral light go out in all conditions, my simple mind has come to think that all of the upstream wiring (from C32, back to reverse diode, forward to C32, and forward through multiple connectors and finally all the way home to the reverse light) is intact without ground... if there was a ground in that upstream section the light would be lit, yes?

So it seemed like I had the problem isolated to downstream of C32, leaving one more connector, C59 and the Neutral Switch / Gear Position Switch as possible locations for the short. Mark is wondering about the side stand at this point. Just wait a little longer...

Remove plastics, Right Side Air Duct, Right Side Radiator Fan, locate C59, disconnect C59.


For C59 I'm going to call the half of the connector closer to the neutral light Upstream and the one closer to the Gear Position Switch Downstream.

Continuity test light green/red wire from C32 Front Side to upstream side (neutral light side) of C59 shows continuity, 0.0 - 0.2 ohms, side stand up or down, bike off.

I did the following tests using a test light hooked up to positive battery terminal so when I probed ground the test light would light up:

Bike in Neutral, Side Stand Up: C59 Upstream light on (??), C59 Downstream light on.
Bike in Neutral, Side Stand Down: C59 Upstream light off, C59 Downstream light on.
Bike in Gear, Side Stand Up: C59 Upstream light on (??), C59 Downstream light off.
Bike in Gear, Side Stand Down: C59 Upstream light off, C59 Downstream light off.

So it looks like the neutral switch works fine as from C59 to neutral switch, I get ground when I should. But something funny is still happening upstream, towards the neutral light, where I am getting ground when the sidestand is up.

Next I disconnected C32 and did the tests again. Same exact results.
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SOOOOOO. Somehow, that light green / red wire, between C59 and C32 (remember C32 and C59 are unplugged) is getting a ground only when side stand is up.

CT1500 pointed out there is a splice in that wire not shown on all diagrams it looks like it runs to C49 Engine Control Module.

I don't see side stand switch on the "lights and switches" diagram but it is on the "ignition system" diagram and has 3 wires. Yellow/Black runs from side stand indicator light and gives path to ground. The 2nd wire connected to the switch is Green for Ground. The third is Green/White which among other places goes to Engine Control Module.

I don't like where this is going (Engine Control Module).

Help?

[AZgl1800]

I don't like where this is going (Engine Control Module).

I doubt very seriously the ECM has a problem.
it has to be in the wiring harness somewhere.

[DenverWinger]

Look at first page of diagrams again, both the "neutral" line and the "Side stand up" lines go to reverse control module too, more lines to trace.

[ct1500]

But remember bike in gear with side stand down kills engine which the splice wire to ECM probably plays a role in triggering event. So the neutral light remained on with gear shift sensor wire disconnected? Too early to fully comprehend your post but would remove that one wire from ECM with everything else plugged in as a next step.