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Hi guys, I'm new to the site and love it already. I just purchased a 79 Bronco and have been working to get it driveable and safe. One of the last issues I'm trying to fix before I move onto the body is the instrument cluster lighting. None of it turns on. When I pull the switch, all of the outside lights turn on and I replaced the fuse that controls that just in case. I'm checking right now to see if I have a short but, as electrical work is not my strong point, I was wondering if anyone else has had an issue like this or can help?

Thanks, Elliott
 

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I got the same issue and I will be watching your thread. My limited knowledge is to pull the cluster and check the connections of all the bulbs in the cluster. I have seen one online and it appears to be a red thin sheet of electrical circuit board. I havent pulled mine yet due to fear of what I will find and lack of know how. thanks for posting I will watch.
 

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Just pulled mine, all the bulbs are intact, which leads me to believe it has to be the light switch since the fuse isn't blown. I'm gonna go buy a tester and a new light/dimmer switch tomorrow. I'll keep you updated if I figure it out.
 

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There is a small box on the back of the instrument panel, I believe it is a resistor or transformer (can't remember which) which might be bad, check this first. I know you can buy replacement ones through LMC or Dennis Carpenter, not sure if Jeff's Bronco Graveyard has them.
 

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yo,
yeah, ck the bulbs out and ck; this out to help w/bulb numbers if missing some

Cluster & Warning Lightings Parts Break-Out Diagram in 78-79 w/ Nomenclature
Source: by Ford via broncograveyard @ http://broncograveyard.com/dia/7/dasdiainstlights.jpg
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Also, for posterity
Instrument Voltage Regulator (IVR) Location & Causes of Erratic Gauges in 78-86; "...The cluster "voltage regulator" is going bad, and staying on too long, sending too much current through the gauges & sensors. It has finally locked on, and is burning out your sensors every time you turn your key on. :( Remove the instrument cluster and then pop the VR off the film circuit - it's a metal box with 2 brass snaps. They're available at most parts stores for a few bucks. The hardest part will be getting the headlight & wiper knobs off, so post again if you need instructions on that.In this photo, counting from the RIGHT, it's between the 2nd & 3rd black bulb holders along the top of the cluster. You can see the hex screw holding the mounting tab, and just below that, you can see the 2 brass snap terminals..."
Source: by Steve83 (Steve, That dirty old truck) at http://fullsizebronco.com/forum/showthread.php?t=22908&highlight=ivr
 

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@ miesk5 and Ziggy
Thanks guys, I bought a switch early this morning and put it on, the lights still didn't work. (Although my gauges seem to work fine.) Before I read your posts I was testing the wires leading into that circuit film thing. The plastic in which the lights twist into is rotted out and some of the bulbs don't work because they won't stay in place and others, when put into place are stuck on. I'll try replacing the IVR your talking about and go from there I suppose. What do you mean about getting the headlight and wiper knobs off?

Thanks for the help and the picture guys, I appreciate it.
Elliott
 

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Usually its a corroded connection or as you have found, the plastic has crumbled away, not allowing proper contact with the printed circuit.
 

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If your circuit film is falling apart as you say, I would say that this is causing some or all of your issues. I believe I have seen these for sale either in LMC, Dennis Carpenter or Jeff's BGY. If the bulb sockets are not staying in place, then slightly bend the small brass connectors on the sides of the sockets to increase the spring tension, this helps hold them in place.
 

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Discussion Starter #10
Hey Guys,
So I priced all the stuff I would need on LMC, and a couple other sites you guys recommended and just decided to go to Pick N Pull and get the whole instrument cluster. Pulled it out of an early 80's F-150 and everything works like a charm.
Huntsober, I would recommend doing that if you want it done on the cheap as the circuit paper and the plastic backing plate to the instrument cluster we're gonna run me about $100 to $120 new, online and as it is I spent $10 at P & P. The only down side is that it may not last I suppose...
Thanks, for all the help guys, I'm sure I'll need some more as I move onto the suspension.

Elliott
 

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If they ever go out again, or just to add a cool mod, you can get a pack of those little blue or green leds from any local parts store and drill small holes through the back of the instrument cluster. Looks really cool and it's cheap. I'd show you mine, but I don't know how to post pictures on here >.<
 

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Or you can repair your printed circut board with a defroster grid repair kit.
 
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