Gauges do not work

[Josh Brink]

Hello All,
So....I hooked up my battery cables wrong (idiot) long enough for the wiring harness on the firewall to start smoking, and now my gauges do not work. Go ahead and tell me I'm a dumb @$$, I can handle it. Anyway, where do I start. For what I can tell the fuses under the dash look ok, however I am not a small guy so doing a real good look under the dash requires removing the seat witch I have not done yet.
1966 Belvedere
thanks

 

[moparmarks]

So your human like most of rest of us.
You may have fried the voltage limiter on the back of the cluster.

 

[pnora]

Before you go to far check all the fuses with a voltmeter making sure they are all good.

 

[Swamp Ape]

Wires under my dash shorted out recently and fried a bunch of stuff. I took my dash off and retired it. I was very apprehensive, but happy I did. It wasn’t hard, just tedious. If you end up doing it, take notes and photos along the way. I just worked on it a couple hours a day. I started on a Saturday and buttoned her up on the following Saturday.
I would check the fuses first, but if you released the magic white smoke from the wiring, I’d go through it all just to make sure it is good and you don’t burn down your car.

that’s my $.02

 

[VFilms]

So your human like most of rest of us.
You may have fried the voltage limiter on the back of the cluster.

This is what the back of the dash looks like. I believe this is the voltage limiter @moparmarks is talking about.

 

[AR67GTX]

You can drop the fuse box down somewhat for a better look by removing the big Phillips head screw on the dash frame lip directly below the box. Do your dash lights and the oil pressure light work? If so and it’s just your temp and gas gages not working then the voltage regulator is a good place to start. I think from your description of smoke I would pull the bulkhead connector plugs loose and check for any signs of melting on the plug side and receiver side that could allow cross shorting. Does the alternator gage work?

 

[Josh Brink]

Thanks guys,
Dash lights do not work, oil pressure, temp gauge and spedo do not work. Alternator gauge does not work. Spedo went up to 100 and did not spring back to zero. Headlights, blinkers, tail lights, wipers all work. The bulk head connector did melt where the main wire goes into it. It did not melt where it connects on the inside. I did replace that wire.
Now might be a good time to take the dash out anyway since there are multiple cracks in it.
Ill check it out this weekend.
Thanks again for all your help

 

[Ron H]

Odd why the speedometer would spring, unless there was enough heat to break the internals. Yep - look at the dash cluster circuit board it may be fried sad to say. Ya might know - disconnect the battery before you do this...I could say why...

 

[Swamp Ape]

Odd why the speedometer would spring, unless there was enough heat to break the internals.

I agree with this. When I fried my dash wires it was all dead, but the speedo worked. It is mechanical and should just clip into the back of the speedo on the dash. Maybe attach some pics of your dash and setup. I also agree with pulling the battery cables before you start poking around. It is pretty easy to pull just the gauges (I think). I had to drop my steering wheel to do it, but that was just a couple bolts.

 

[VFilms]

Speedo too. Interesting. If, unfortunately, you fried your circuit board I may have one from a ‘66 Belvedere.

 

[Ron H]

I agree with this. When I fried my dash wires it was all dead, but the speedo worked. It is mechanical and should just clip into the back of the speedo on the dash. Maybe attach some pics of your dash and setup. I also agree with pulling the battery cables before you start poking around. It is pretty easy to pull just the gauges (I think). I had to drop my steering wheel to do it, but that was just a couple bolts.

On my '63 doing some resto on the cluster adding a tach in the dash where the clock was I knew full well disconnect the batt. Well some-ting kept going amiss putting the cluster back in and finally tried to look what the problem was with batt connected. Found the problem; but not before frying one path on the CB...bought a rear-window defogger kit to patch it up.

 

[Josh Brink]

Ok thanks guys,
Ill check it out and let yall know what I find. If I need a new board I will reach out VFillms thanks

 

[AR67GTX]

Wow, even stopped the speedometer. Hard to imagine how that happened. Must have got a jolt like the one that brought Frankenstein to life.