How to check 7 volt regulator

[KerryOkie]

My gas gauge seams to be reading a 1/4 tank my temp gauge seams ok. Not sure how to check the output of regulator. I pulled the connector to gauge and checked voltage and it was about 4 volts. What should it read 7vdc ? I also shorted the pins and the gauge read the same about 1/4 tank.
I've
looked up where regulator was but the only in i could find was on a gl1100.
I have a 1988 gl1500.
Any help would be great.
Kerry

[DenverWinger]

7 Volt regulator is only on the 4 cylinder 'Wings, gas gauge on the 1500 runs on 12v power.

To check your gauge, with the seat off find the fuel gauge sender connection on the tank, with the sender wire disconnected the gauge should read empty, if you ground that wire the gauge should read full. If the gauge does not read these two conditions it is probably a fault in the gauge in the meter, if the gauge reads empty and full correctly then the problem is in the sending unit. You'll need to remove the sending unit from the tank, it is likely corroded. Soak the sender in vinegar for a day, that'll clean it right up.

[KerryOkie]

Ok great info. So just to make sure i dont short something out, I disconnect sensor and ground one or both pins that feeds the sensor to ground. I had about 4 volts across these two pins. When i disconnected them the gauge did drop to empty so now if i can just get it to read full.

So ... Short both pins to ground?

[KerryOkie]

Oh, also this is on a 1988 gl1500
I have the service manual but its hard for me to follow. Its a Six cylinder.

[CrystalPistol]

Had that issue on a Subaru and my 1200, gauge reading low when I knowed it was full. Both cases, it was cured by pulling the sensor / float and tweaking the arm for better contact on the resistor winding.

[KerryOkie]

I don't think its the sensor but I'm going to pull it, clean it and ohm it just to make sure it's set right.
Wish it was but the test i have done leads me to think it's the gauge. Hope im wrong. I can find that part if i need one.

[CrystalPistol]

So, if you crossed (jumpered) the two wires to the sender unit, simulating full, gauge should read full I think.