Have to Chase a Behind Cluster Wiring Problem - 63

[Norm B.]

After finding and replacing a bad wire between the ignition switch and the ballast resister I carefully looked at what I thought was every other wire behind the cluster and I could find no bare wires, cracked insulation, or anything else that looked out of place. I even unwrapped most of the bundled wiring and re-taped them afterwards. I re-installed the cluster and proceeded to start the car. What happened then was that as soon as I turned the switch the dome light went out, the fuel gauge pegged right over to the right, and I started getting a bit of smoke from behind the cluster. Obviously a dead short. In a panic I immediately turned off the ignition switch and ran around and disconnected the battery. That was about a month ago.

Now that I have time to get back at it I thought that the first thing I would do is check all the fuses, they are all good. I then thought that like we all do automatically I did not turn the key to "ON" then to "START", I immediately went right past "ON" to "START", so I did not know which position the problem was at or maybe both. The only way to check that out was to turn the switch to "ON" being fully prepared to turn it off immediately and pull the battery power. When I turned the switch to "ON" the dome light stayed on, the fuel gauge went back to normal, and there was no smoke behind the cluster. Being the brave or foolish person that I am I then turned the key to "START" and the starter kicked in. Getting really brave I then cranked the engine over and it started.

Now, I know I have a short or bare wire somewhere and I am probably looking at replacing all or some of the harness in the long term but in the short term, for my own peace of mind, and to be able to drive the car for at least a bit this season, I need to find and repair the problem. Based on the symptoms does anybody have any idea of where to start? Which circuits should I chase down first? Everything appears to be good but there has to be a problem in there somewhere and this could take days to chase down. HELP!!!

[Gary F.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Make sure the ground wire is good that connects to the cluster from behind. It is a separate wire. Since your problem is going thru the fuse block, pull the wiring connector that comes out of your fuse block , closest to your distributor on the firewall, and check the tangs to make sure their not broken off or have heavy corrosion on them. These fuse box connectors ( firewall side ) are famous for corrosion & shorts.

[Bob R.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Twice I had a similar problem some time ago on my 63. The first time my top shielding hit the wire on the coil and very quickly the wire running down to the starter fried I am now very careful to make sure the coil connections are parallel to the top cover. The second time the capacitor on the battery gauge behind the cluster started smoking on my attempt to start the car. I disconnected the capacitor and the problem went away, every one likes to use original parts but capacitors can go bad. You must have something grounding out the wiring somewhere.

[Joe R.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Norm,

I believe you have a bad ignition switch. What happens is the carbon tracks from the "ON" terminal to the "START" terminal and starts to arc. It can be serious if you leave the switch in the on position. The carbon burns VERY HOT and can burn up the switch if the arcing doesn't stop.
There should be a burned or distorted spot on the back of the switch.
May be hard to find an original 63-64 switch that is correct. There are replacements that will work.

JR

[Norm B.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Thanks for your suggestions guys.

Gary - The ground wire is on and good. I pulled the connector at the firewall and although not perfect it is not in bad shape.

Bob - There is no shielding on the car right now. I did look at the ammeter capacitor and the wire seems to have been quite hot at some time. It is distorted and brittle so you may have hit the nail on the head.

Joe - The ignition switch shows no sign of burning or distortion.

I am still a little puzzled at what would have made the fuel gauge peg right over to the right.

Also, I just noticed tonight there is no ground wire in the connector to the ignition switch and no evidence of one anywhere in the harness. Is this correct, and if not could it have been the source of the problem?

[Norm B.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Just answered on of my own questions by looking at the wiring diagram. DUH! There is no wire showing in the diagram to the ground post on the ignition switch.

[Gary F.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Here's a shot of the wiring diagram from the 63 shop manual, showing the ignition & related wiring. ALL wires are color coded, so this wiring is very simple to follow right thru the fuse box to your engine compartment. Shop manuals are cool to have. The diagram shows an open space in the ignition for GND, so there never was one to begin with for the ignition switch. The fuel gauge pegged, so that means ground, because it gets power immediately when you turn the switch. Check the connector that feeds power to your taillights also. Have you installed anything lately, or moved stuff around by the dash? Really sounds like a ground that looks good, but really isn't.[IMG][/IMG]

[Dan H.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

years ago I put a wrong wire on my 63 cluster on the ground lug on the back of the cluster, instant smoke, think it was brown with single lug. Was a hot wire. make sure of the correct colors to each terminal. Good luck!!!
Dan

[Norm B.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

IT'S ALIVE! I have traced every wire and circuit that I could find behind the cluster and under the hood, physically checked insulation, and made sure that all the connections are on and in the right place. I left the capacitors disconnected just to be on the safe side. I have an aftermarket radio in the car, (Yes I kept the Wonderbar and it's safely tucked away).The car starts, runs, everything works as it should including lights, wipers, heater, etc. and the alternator is charging the battery the way it should. I may have inadvertently corrected the problem or one of the suggestions made here was the solution. Just to make sure though I am being diligent about the battery disconnect and I double checked that my fire extinguisher is fully charged and within reach. Thanks for your input and suggestions guys.

[Gary F.]

Re: Have to Chase a Behind Cluster Wiring Problem - 63

Totally KOOL to hear!!!!! The best part is that you looked at all your connections for any more issues!!!!! ENJOY THR CAR!!!!!!!