Gas guage not working after cluster swap
 

Hi guys, new member here. I just swapped my dash cluster out for a tach cluster that is original (not repop) but was cleaned up by the guy I got it from with new lens and bezel, so it has been apart. Now my gas guage is not working and the needle stays at 2-3 o'clock. All other guages and dash lights work fine and everything worked on my old cluster. I do not think it is the sending unit as I have no power (with key on) at the fuse block terminal where the brown sender wire plugs in. I have not had a chance to check anything else yet so I thought I would get some pointers from you guys. The truck is a 70 C10. Thanks.

Re: Gas guage not working after cluster swap
 

Check for the gound. If the panel is not grounded good the fuel gauge acts kinda messed up. I chanced this issue for a while before I figured it out. I just added a extra ground strap from the back of the panel to a good solid clean location under the dash.

Re: Gas guage not working after cluster swap
 

Thanks CTST10, I figured it was a ground problem. When you say you added an extra ground, do you mean to one of the 3 posts at the rear of the gauge or to the metal housing surrounding all the gauges?

Re: Gas guage not working after cluster swap
 

Ground the terminal at the fuse panel marked FUEL and with the key on the gauge should go to empty. If it does then the gauge and panel are grounded an the trouble is in the sending wire or the sending unit in the tank not being grounded.

ground the sending unit wire at the tank and watch the gauge. If it moves the problem is in the sending unit or the tank is not grounded. If it does nothing, the wire is broken and you need to run a new wire.

Re: Gas guage not working after cluster swap
 

Do you have, or did you have a 2nd fuel tank in the truck at some point?
I have a 2nd tank in my truck and it has its own toggle switch under the dash. I've never used that tank but the switch is still there for it....and if it ever gets 'switched' my gas gauge goes to zero/empty. Took me a while troubleshoot that one originally....lol.
All Good
Coley

Re: Gas guage not working after cluster swap
 

Sub'd

Re: Gas guage not working after cluster swap
 

No it doesnt have or ever had a 2nd tank. The problem just started after I changed clusters and the gas gauge worked fine before the swap, thats why I think the sender and the brown wire are ok but anythings possible. Tomorrow is my day off and I plan on looking at the problem more closely. The sender grounds to the fuel tank, right? How/where does the cluster ground?

Re: Gas guage not working after cluster swap
 

I had a simular problem.Might be best to just ground the sending unit. drill small hole in tab and ground to the cab.

Re: Gas guage not working after cluster swap
 

An update: I checked the brown sender wire for continuity- good. Did a ohm test on the sender- good. As I was getting ready to pull the cluster out I figured it wouldn't hurt to wiggle the harness a bit and make sure connection is good. Shazam! We have a working gas gauge now! It's always a good idea to rule out the easiest and obvious before scattering parts all over the garage.