91 GMC S-15 Jimmy 4.3

Couple things here that I hope somebody can help with,
1- the fuel gauge does not go all the way to empty, it will run out of fuel at about 1/4 tank, any ideas why?
2- my temp gauge just flickers up and down as I press the gas peddle, usually if my truck is parked and I hit the gas or hold it at a high idle the gauge will just hit the limit and stay there till I let off the gas then drop down to what I think is the actual temp,but sometimes it will flicker up and down instead of stayin steady,now if im drivin it does the same thing but sometimes just flickers up and down. the sound is kinda anoying LOL!!!

any help would be great

like I said in subject line its a 91 GMC S-15 Jimmy 4.3, non vortec and not a digital dash.

THANKS

There is two possibilities as to why you run out of fuel at 1/4 tank either you have a bad ground or you have a bad sending unit. The same with your temp guage eith a bad ground or the gauge itself could be bad.

The reason for it showing 1/4 when empty could be the gauge, sending unit or the float. As for the temp gauge, sounds like an electrical issue, i'd start by checking all wires and maybe replacing any melted or frayed ones . I wouldnt worry too much about it unless the sound is pushing you towards a nervous breakdown

Sounds like instrument panel problems since two gauges are malfunctioning. It can be the plugin and poor ground like mama said or it can be a solder connection that broke loose.

Just to be sure, check your coolant level and make sure it's full (no leaks).

Then I would change the $10 temperature sending unit for the gauge. I'd give you the specs for testing it, but I don't have them handy. Some of them had 1 pin and some 2 pin connectors.

It's located on the side of the head on the passenger side.

Then I would see how the gauge reacts and we can go from there.

Thanks for the replies Grease Monkey,mikulas19,and TennesseeMama.

I should say that when I bought the truck I had to replace both window motors and the wiper motor also some other sensors under the hood so it would seem that there was or still is some sort of major electrical problem with the truck before I got it.
The gauges have been like that since I got it also.

Sounds like instrument panel problems since two gauges are malfunctioning. It can be the plugin and poor ground like mama said or it can be a solder connection that broke loose.

would it be possible that the plug in needs to be cleaned(if I remember correctly its like a ribbon plug in that the instrument cluster plugs into) also I thought that I read somewhere that there are resistors on the instrument cluster board that sometimes burn out?
Also do either of you know where the main body ground(s) would be located or the approximate location of the ground(s)?
As far as the fuel sending unit ground I know it is good because I pulled the tank this past summer to replace a fuel line and I re grounded it in hopes it would fix the gauge but it didnt.

I guess I will just start with the temp sending unit like you suggest Grease Monkey and let you folks know where that gets me,guess Ill be buying a new fuel sending unit too.  

I fear that I'll be chasin wires down ugh the worst thing to have to do on a vehicle LOL

I wouldnt worry too much about it unless the sound is pushing you towards a nervous breakdown

 

Honestly Im ready to yank the instrument cluster out and toss it out the window and just wait to get pulled over to see how fast I was goin...LOL   CLICK CLICKCLICK CLICK CLICLICLICLICLIKKKKKKKK CLICK...

Try checking the sending unit on the motor. That could be bad. You could also just try replacing the whole instrament panel. We had a problem like that once and bought a used one through a junk yard; wasn't all that expensive either. But first check your wiring and sending unit.