63 electrical problem stumped

[Thomas S.]

63 roadster, 327/340, 4-speed. I started having issues with the radio going off momentarily the back on which in itself would not cause me to post on the forum but it gets more puzzling. Typically the power loss to the radio was limited to around 5-seconds. Now the problem has evolved to also include the car stalling, presumibly from a loss of power. It always starts right back up.

Today I was crusing about 35MPH and lost electrical power. i actually thought the engine was running but then realized the mechnical tach would keep turning withou power. The ignition key was still on and I had expect the the engine to start back up at some point, No luck so coasted off the road and restarted the care about 15 seconds later.

The starter was removed recently for a clutch change and I did check the connection to the solinode and starter. The connections to the firewall were pulled and looked fine. Battery connections are good.

I beleve if there was an issue with instrument harness (powers the radio + ) that the engine would still be unaffected. I'm leaning towards a possible ignition swith or ignition switch connector issues since that could cause the engine to quit and also affect the radio. Not sure what else would be common to both problems.

????

Tom

[Leif A.]

Re: 63 electrical problem stumped

Tom,
It's very possible you have two separate issues. The car losing power while driving could be a ignition coil going bad or the capacitor/condenser inside the distributor cap. The radio issue is probably internal, although I can't give you anything specific. Best of luck in tracking down the problems...electrical gremlins can be a real PITA.

[Richard M.]

Re: 63 electrical problem stumped

If it starts right back up after stalling my first thought would be since the IGN switch is the next electrical switch movement on successful restart, then it would point me to that item....the IGN switch. Every time you restart it may be wiping the internal switch contacts clean for a moment then open circuits as current passes through corrosion/dirty contacts. The IGN switch, during RUN, also powers the ACC circuit, radio, heater, etc.

You could also connect a voltmeter to the back of the IGN switch Bat+ feed and IGN and ACC wires, independently, and run the engine(parked) and wiggle the wiring, and the key itself, to try to isolate/create the fault.

The other thing that may cause this type of fault, if the Bulkhead Connections are good as you stated, is the internal Main Power feed connection on the back of the fuse panel. Those terminals may be corroded and create a intermittent fault.

Dual Red is Main Feed from Bulkhead which also powers IGN switch. Brown is ACC power from IGN switch,

[Thomas S.]

Re: 63 electrical problem stumped

Thank for the reply. Two seperate issues is a possibility but the correlation of each failure would indicate otherwise. The radio is an obvious indicator of power loss so I may temporarily hook up a meter to hot line on the same harness to see if the power loss is accross the whole harness. Obviously a little nervous about getting stuck high and dry, but driving it at night would also provide some more clues as the dash lights would go off if it was a harness issue.

I'm running the correct coil and resistor. But will try replacing the both to see if that makes a difference. I own an electronics manufacturing company so I do have trouble shooting expertise. Lossing the radio is no big deal but an engine shut down is a real safety issue.

[Thomas S.]

Re: 63 electrical problem stumped

I agree with you about the switch and plan to stick in a replacement over the weekend. I did play withe the connector to it during idle to see if that might be it but nothing happened. It is an original switch, or at least one replaced by another original. So the switch is the next thing I plan to focus on. Thanks for pointer on the bulhead block.

[Richard G.]

Re: 63 electrical problem stumped

In the past I have attached a test light to various circuits and then went for a drive.
It should help identify what part to look at.
In your case possibly two lights. One to the switch power and another on the switch output....
See if they both go out or just one!
I hate to see electrical parts changed out sans proof.
Hard on the wallet...
Rick

[Frank D.]

Re: 63 electrical problem stumped

I had similar issues with the 63 - a bulkhead connector was pushed in and the plastic housing tabs were broken off.
I 're-pinned' the connectors under the dash - NOT for the faint of heart..

Lectric Limited sells the kit while, at the same time, advising you not to do it ad, instead, buy a whole harness - but I'm thick-headed..

[Thomas S.]

Re: 63 electrical problem stumped

The plug off the harness is in good shape but I haven't checked the mating pins on the block. That should be easy enough. I've dealt with types of spring retention contacts and the key is having the correct insert and extraction tools. Looks like that kit contains them. I have to in there and wiggle those wire a bit with the car idling.

I may be wrong about this, but the only thing inside of the car that could kill the engine would be the ignition switch or connections to it. That's also true of the radio.

[Thomas S.]

Re: 63 electrical problem stumped

I threw in a new ign switch, took the car out and it died a few blocks away. The starter would even crank but after about 10 seconds I was able to fire it up. Another stumper.

When I got back to the house, I played with each connector in the engine compartment. I was able to get the car to stop running by messing with the connector that is closest to the left front fender. That harnes travels towards the front of the car up along the top of the left inner fender.

Is the photo you posted off a 63?

I took your advise and looked at my block and found a bad splice. However my block was set up differently. i didn't see any wires for the turn signal flasher in your picture. Mine had the main red feed with a tap to one of the connectors to the turn signal flasher. That tap "Y" was the wire that had been spliced. There was some bare conductor showing and adjacent wire had burn marks. I also cleaned up the contacts on both bulkhead connectors and harness connectors.

I had the car idle for about 20 minutes and no issues but regular driving will be the true test.

[Frank D.]

Re: 63 electrical problem stumped

If you're asking me - yes the connector pictures are off my 63 coupe.

[Thomas S.]

Re: 63 electrical problem stumped

Yes i was asking you about the fuse block. I have a roadster. i didn't realize there were two different fuse blocks.

[Thomas S.]

Re: 63 electrical problem stumped

The image from Fank corresponds to the 63 AIM with the 12AWG red wire at the bottom of the block and a split off of it to the bottom left for an option. In my case however that red feed is in the position that is shown as BROWN in the AIM with a split to one leg of the turn-signal flasher.

[Jim T.]

Re: 63 electrical problem stumped

Why did you have to remove the starter just to replace the clutch (clutch disc and pressure plate)? When I changed the clutch on my 1968 I did not mess with the starter wiring and remove the starter. Maybe the problem is with removing the starter wiring going to the starter solenoid.

[Thomas S.]

Re: 63 electrical problem stumped

The clutch/flywheel resurfacing/ drive shaft rebalance was done by a local Corvette only repair shop with decades experience. I didn't mention the full extent of the repair.

That said, all of the connections are correct and tight below at those points. As I had mentioned initially, there were two simultaneous electrical failures and at the time it I did not see anything common to both. I have since done a few things (process of elimination) that I thought might be in common with both issues. Replacing the ignition switch was one but that didn't solve the problem.

I took pull the fuse block from underneath the dash and also cleaned all oxidation from the two bulk head connectors as well as the mating harness plugs. In the process of examining the fuse block I came across a bad splice between a power lead and the turn signal flasher. That wire had been poorly repaired and was actually bare in some spots. Adjacent wires had burn marks as well. So that was fixed

I also noticed that the the position of the feeds were incorrect. There are two, a 14 AWG Brown, and a 14 AWG Red. The Brown should be at the top and the Red at the bottom. They are reversed. The problem is that the Red wire would not reach the bottom of the block so it looks to be correct.
It works because they are both feeds but I have to dig into this a bit more.

[Thomas S.]

Re: 63 electrical problem stumped

Richard, is the picture you posted from a 63? The reason I ask is because there are no wires going to the slots for the turn signal flasher. My block has wires to those locations.