67 Mustang Wiring Problem
filed in 67 Mustang
Question: I have been working on this for a while and am ready to give up – maybe someone can help me out….
I have a 67 Mustang that suddenly lost all power to the dash except for the turn signal indicators. No dash lights, gauges, etc., only the blinkers work. The dash fuse is good as is all the other fuses in the junction box. However, there is no juice getting to either side of the fuse. So somewhere between the hot source and the fuse, it is broken. I have a wiring diagram but cannot figure out where the hot should originate – maybe the ignition switch? There must be a common source of “hot” that has an inline fuse or has come unplugged, but I can’t find it. Perhaps someone here has seen this, or has a suggestion on how to track it down.
Just a guess, but a dead ground to the body can cause issues like that and if you used the dash as the ground for the meter, then it still would show 0 volts at the fuse.
I would be running a booster cable from the battery negative to the firewall or dash itself and see what happens.
Other than that I recommend a repair manual like Haynes which is cheap and gives you the wiring schematic.
The dash lights also go through the headlight switch. Headlight switches are cheap and fail more than just occasionally on old beasts. Have you checked continuity on the Black/Yellow wire from the +battery terminal on the starter relay to the fuse panel? It goes through a 3 prong connector so check for bad connection there. There is also a tap after that connector that goes to the light switch so if that connector is bad then you’ll lose the constant power to the 7.5 amp fuse and the light switch. BTW clean the eyelet connectors on the terminal of the + battery cables too. often they may look clean but take them apart and get an emory cloth or bard and sand them shiny as that is where the contact is made. LMK if you need any more clarification. Good Luck!
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