Dash not lighting up
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Dash not lighting up
Hey, I’ve been putting a 79 back together out of 3 trucks, I received a harness with a 14 prong cluster, I thought I plugged everything back to the way it was including grounds, when I pulled the switch to turn on the lights only the side markers work and head lights, nothing in the cab lights up, except the right turn signal indicator on the dash stays lit, I do not have the rear wiring harness attached yet but I figured the dash would still work, I never was good at wiring, I took the gauge cluster back out and cleaned all bulb connections and checked with a test light, put back in and same problem, when I go to start it the oil lamp stays on but it’s getting oil fine, the seat belt dummy light also works, I had to use the alternator wiring harness from a bronco with a 18 plug and I thought I hooked it up right but two wires aren’t connected to anything, no markers on the turn signals at all either, anyone got any ideas?
Fleet Mechanic
Joined: Jul 2017
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From: KY
Hey, I’ve been putting a 79 back together out of 3 trucks, I received a harness with a 14 prong cluster, I thought I plugged everything back to the way it was including grounds, when I pulled the switch to turn on the lights only the side markers work and head lights, nothing in the cab lights up, except the right turn signal indicator on the dash stays lit, I do not have the rear wiring harness attached yet but I figured the dash would still work, I never was good at wiring, I took the gauge cluster back out and cleaned all bulb connections and checked with a test light, put back in and same problem, when I go to start it the oil lamp stays on but it’s getting oil fine, the seat belt dummy light also works, I had to use the alternator wiring harness from a bronco with a 18 plug and I thought I hooked it up right but two wires aren’t connected to anything, no markers on the turn signals at all either, anyone got any ideas?
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I know I might have to replace the Alternator harness. I replaced the switch since it had a bad connection in it and it sends power to the blue and red wire(instrument lighting) all the way to the 14 prong cluster, I plug it in the 14 prong and all I get is a turn signal light that stays lit, took all the bulbs out and replaced and cleaned them, put it back in same thing, I even ran a wire off of the red and blue and a ground to a 18 prong and same exact thing, I was thinking about replacing the 14 with the 18 but it sounds like too much work, the harness that’s in it came from a 76 dump truck cab with cab lights, the dash is also a 14 prong that was a 79 cab that was butchered, the alternator harness is also a 79 bronco but that had a 18 prong in it
Lead Driver
Joined: Jul 2017
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From: San Jose, CA
Were all three trucks '79's? I know the early 5-fuse panels had the dash lights handled through the smallest fuse. Not sure if the later 10-fuse(?) panels used the same one, but it should be marked and is probably still a very light fuse like 5a or less.
But even with that said, either way, did you try spinning the **** in both directions to make sure that you had the light brightness all the way up? You won't even see any voltage on the fuse or wires at the bulbs if it's turned down.
And what about grounding wires? Any and all loose ground wired re-connected under the dash?
Do you have good body grounds? There should be one from the battery to the body nearby, and one from the back of the engine to the firewall. Heck, they even grounded the hood to the body with a braided strap and had at least one braided strap per side between the frame and body mount, jumpering/bypassing the body insulators. Probably to keep radio noise on AM to a minimum.
But good grounds help keep the gremlins away.
Paul
But even with that said, either way, did you try spinning the **** in both directions to make sure that you had the light brightness all the way up? You won't even see any voltage on the fuse or wires at the bulbs if it's turned down.
And what about grounding wires? Any and all loose ground wired re-connected under the dash?
Do you have good body grounds? There should be one from the battery to the body nearby, and one from the back of the engine to the firewall. Heck, they even grounded the hood to the body with a braided strap and had at least one braided strap per side between the frame and body mount, jumpering/bypassing the body insulators. Probably to keep radio noise on AM to a minimum.
But good grounds help keep the gremlins away.
Paul
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