Power windows and gas gauge broke?

[badbowtie03]

Hey everyone I have an 87K5. Both gas gauge and electric windows were working... I don’t think it’s related but I tuned the truck up... plug wires distributor etc... Then the next morning the gas gauge was on empty... ground issue? Anyways today I checked the ground by the gas tank and unplugged and plugged back in the wiring for the fuel pump. It all seems fine?

So also, two days after the gas gauge quit... both front electric windows stopped working at the same time... One night they worked and I put them up and shut the truck off then when I tried to start it in the morning they wouldn’t go down...

Could these be related? Maybe an ignition problem? I checked the fuses under the dash and they seemed fine. Should I take a door panel off and see if power is going to the electric switches? Any ideas? Thanks so much!!

 

[6872xtc]

I would guess that the problems aren't related, but maybe I am wrong.
The gas gauge goes past full when it loses ground on the sense wire, and I believe that it quits moving when it loses power.
With the windows, you should be able to find the plug near the bottom of the dash at the kick panel, and see if you find power there. But confirm which circuit you are checking by pulling fuses one at a time to see which one is the window circuit and which is the power locks.
The reason that I suggest checking there is that the wires in the door jamb can break and lose connection to the switch in the door panel. So if you pull the panel and check there, then remember to check that other plug if there isn't power at the switch.
Did you check the passenger window at the switch in the passenger door?

 

[badbowtie03]

Thanks so much. I am going to try and check it now

 

[badbowtie03]

It was a bad ground wire behind the door panel. So i just grounded the wire to the door frame on one if the bolts and it worked. Didnt figure it was worth finding the ground up under the dash! But now that i already did it... makes me wonder if thats the gas gauge issue also? But it is pegged on empty... you had said empty meant no power.

 

[rampage]

It was a bad ground wire behind the door panel. So i just grounded the wire to the door frame on one if the bolts and it worked. Didnt figure it was worth finding the ground up under the dash! But now that i already did it... makes me wonder if thats the gas gauge issue also? But it is pegged on empty... you had said empty meant no power.

No +12V is the same thing as no ground. You need two power wires to make a complete circuit, a positive and negative (ground). Applying 12V to something doesn’t make it work without a return path for the current - i.e. ground.

 

[badbowtie03]

So I am definitely not an electrical guru by any means... just trying to follow what you meant. Basically what i did was use a test light. I found it had 12v positive with the key on right at the window switch behind the door panel. But there was no ground going to the switch. When i grounded the switch on the frame of the door... i got it working.

 

[badbowtie03]

Oh wait, you referring to the gas gauge? Sorry about that.