76 Fj40 Guage problems

[Trollhole]

My 76 Fj40 with stock engine. The guages do not work. the only one that does is the alt one all the others including the illumination lights do not work. But one blinker works. I took the guage cluster out last night and looked at the back. It looks like the previous owner had other wires connected to the individual guages in the back but they actually go to no where. Mine has this plug in the back and I know they go to each individual guage and lights and blinkers. I used the wiring diagram for a 78 fj40 to trace the wire but no luck seem to be different colors to me. There were multiple yellow black wires. I toned all the wires going from the guages to the senders and they tested out ok.

My question is. Is there one common wire that powers the guage cluster? And what color is it. Can I bypass that wire and tap into the guage cluster? Does anyone have a wiring diagram of a 76 FJ40? It's driving me crazy not knowing temp, fuel, and oil.

 

[warhorse]

I have a wiring d for a 76.. whats your email and i will send it to you

 

[jaybonecrow]

The fuse for the heater runs ALL the guages on the dash except for the ALT. Try the fuse. Worked for me.

 

[Trollhole]

marshall_shepherd@msn.com Thanks

Yep, checked the fuse. Still no go.

 

[Trollhole]

Gauge hell

This is what I have found. The blue red wire #4 comes from the heater and has power. I checked each gauge with a 9v battery and each worked fine. But still no fuel, oil, or temp working. It's really getting to me. Where should I go from here. Could a short cause all three to go out. One thing the oil will not work because the previous owner replaced the sending unit and guage with a manual unit under the colum. If the oil pressure wire is not hooked up will this cause all the rest to fail? I need temp working and I ran out of gas this morning because the person who I bought it from told me he filled it up. It's only been 40 miles!. I made this drawing to show what I have surmised so far. The guages are flipped( that's why the lettering is backward) so I could get everthing to line up.

Anybody have any Ideas?

 

[IDave]

Everything is in backwards! That must be yer problem!

 

[Trollhole]

Well I figured it out. The fuel guage had a burned contact causing both fuel and temp to not work. Had to take the guage apart to resolder. Works like a charm now.

 

[Macgyver5]

Hey, I am having similar problems except mine will either all work or all not work (excluding the amp guage) I've noticed that the only time that they will always work is right after I fill up my gas....The they'll randomly work or not work .......or work and then quit working while I'm driving...=o).....any ideas???

 

[Trollhole]

Pull you gauge apart clean all the connections very well and inspect the fuel gauge for any problems. The space under the connectiong nuts gets corroded over time and looses continuity.

 

[yellowstoner]

Trollhole, to disassemble the cluster, do you remove all the nuts and screws off the back and that's how you had access to the fuel guage in order to repair it? I am having a problem with the temp and gas guage. Seems like my gas guage worked before I removed and reinstalled the tank. I have installed a new temp sensor on the head but that didn't help. Thanks

 

[Trollhole]

If I remember correctly you just remove the phillips screws. But I think the guages hinder it from comming all apart so I think I took the copper nuts loose also. It won't hurt if you do and you get access to clean behind the nuts. JUst take a couple of pictures as you go for reference. Also while you are in there do the bulb screen mod.

 

[yellowstoner]

Thanks

I will give it a try. Do you recall what bulbs you upgraded to?

 

[Trollhole]

I will give it a try. Do you recall what bulbs you upgraded to?

https://forum.ih8mud.com/showthread.php?t=69423&highlight=light+bulb

 

[yellowstoner]

Excellent, thanks!