So the other night I was driving the colony park and the fuel gauge stopped working, just suddenly dropped to below E. Also my gauge cluster lights stopped working. These may or may not be related, the cluster lights have always been flaky, and I didn't notice if they were on or off when the fuel gauge went out because it was still light at that time. Sadly all I have at the moment is the chiltons manual and I have been through the wiring diagrams 5 times now and cannot find any reference to the fuel gauge. Does anyone have any better wiring diagrams or an idea of were I should start? I did not find any blown fuses.
I have a 77 Ford LTD II, and just started having issues with my dash lights the other night. My gas gauge hasn't worked, since I bought the car. So, I'll be watching your thread for suggestions.
My first suggestion is to check the ground on the IC. Having both go out at once would suggest that there may well be a ground issue. If it is just the lights that have gone out, the thing to check is the rheostat in the headlamp switch. That is a difficult switch to replace, too, since it operates both the headlamps, etc, as normal, but also the vacuum to the headlamp covers. For the fuel gauge issue, check the ground on the sending unit. It could be a bit wonky.
If that doesn't help, I have the factory manuals for the 78 Ford/Mercury models, and I will copy the diagram and mail it to you. I can't scan it since I don't have access to a scanner, worse luck.
STRONGLY suggest you get this set the 1978 ford shop service manuals http://www.ebay.com/itm/1978-Ford-L...anuals_Literature&hash=item5aed3cfa0d&vxp=mtr i bought the 3 volume set for my 84' country squire and it's been absolutely invaluable. the gas gauge on my squire has been dead since purchase also. the original owner jacked up the dash wiring which doesn't help. have repair receipts from the original owner showing both items. it's one of several posibilities, the fuel sending unit in the tank itself is bad (float filled with gas) or the voltage regulator behind the dash. if it worked before, it could very easily be either. im replacing both on my squire, and just bought the sending unit from a junkyard dealer on ebay. the gauge cluster is next. hope this helps somewhat. Will Hemb
The sending unit may well be available new still. I don't know for sure, but I suspect it may be. And it was the wiring diagram from the factory service manual I had said I would photocopy if you need it.
While I suspect I have to tackle the sending unit sooner or later since it's always been more of a guess gauge than a gas gauge, I'm suspecting a different problem on the gauge itself since the needle literally dropped clean off the face very quickly. Ground issue is very likely. Thanks for the link on the shop manuals, they are definitely on my list to purchase, just been waiting for the bank account to recover from the holidays.
you can ground the tank by drilling on the OUTSIDE part of the seam using a sheetmetal screw and then drill and ground to the frame with a new wire quick dependable fix if its just a ground.
I need to take the wagon some place tomorrow so I went out to do a systems check tonight and the gauge is working again. Gotta be a loose connection somewhere.
the gauge could be a few things...but as for the dash lights....thats a chronic 76-79 F&M problem !!! sometimes its the switch itself...other times its the 'hi beam' switch shorting the Headlight switch out My old 79 Tbird....the lights would just go out whenever they felt like it i'd pull and push the switch a few times ...and they'd come back on !!!! .....goofy
If it is the high beam switch, the fix is simple. They are readily available. For that matter, Gear Vendors uses that same switch for their over drive units, that is how easy they are to get! Worth a shot, that's for sure.
