'63 Coupe Electrical Issue

[Norm B.]

[Mark E.]

Re: '63 Coupe Electrical Issue

I once had a '69 Cadillac CdV with a radio that would not work with low battery voltage. It was like an audible voltage warning. Maybe the brake lights and horn caused a significant voltage drop due to a weak battery and/or charging system. Charge the battery, test the charging system and check for an intermittent/poor/loose connection in the charging circuit (battery- starter- alternator- horn buss- ground wires). I'm wondering if the battery was low, then charged up on the drive home.

[Norm B.]

Re: '63 Coupe Electrical Issue

I once had a '69 Cadillac CdV with a radio that would not work with low battery voltage. It was like an audible voltage warning. Maybe the brake lights and horn caused a significant voltage drop due to a weak battery and/or charging system. Charge the battery, test the charging system and check for an intermittent/poor/loose connection in the charging circuit (battery- starter- alternator- horn buss- ground wires). I'm wondering if the battery was low, then charged up on the drive home.

That is a good thought Mark. The battery is relatively new and in good shape but it took quite a lot of cranking to get it going that time as it has the typical AFB leak down issue when it sits for quite a while. In the meantime it wouldn't hurt for me to check out all those other connections as you suggested.

[Edward J.]

[Bill B.]

Re: '63 Coupe Electrical Issue

Norm,

I think you can be alleviated by the thought of a short circuit as cause. If your inspection of wiring did not uncover any "burnt" or discolored wiring, a short circuit as cause is unlikely. I like Mark's theory, as both the horn and the brake lights do draw a moderate amount of current when activated. Another possible cause may be an intermittent bad connection or weak fusible link somewhere in the vicinity of the horn relay or bad connection in the fuse block. I had a similar situation, (but not radio going out) with a fusible link jumper located on the horn relay of my 1970. I don't know if the horn relay on a 1963 was similarly used as a voltage distribution source like the '70 was, but just guessing it may have been, and if so, another place to inspect.

[Paul Y.]

Re: '63 Coupe Electrical Issue

That is a good thought Mark. The battery is relatively new and in good shape but it took quite a lot of cranking to get it going that time as it has the typical AFB leak down issue when it sits for quite a while. In the meantime it wouldn't hurt for me to check out all those other connections as you suggested.

I had an electrical problem years ago with my 63 when I was daily driving it and pulling a trailer. I found the culprit at the back of the fuse panel on the firewall engine side. The connection came loose and was not getting contact which was exasperated by pushing in the clutch. The contacts were gently cleaned and rejoined with some dielectric grease. I is a somewhat vulnerable position in a rainstorm with puddles. Worth a try anyway.

[Richard M.]

Re: '63 Coupe Electrical Issue

Likely a under dash wire is getting moved around and causing a "open" circuit. Best to do a detailed visual inspection, particularly near the pedal lever pivots and Park brake mechanisms.

Bill, FYI fusible links began in 1967. Yes 1963 used the horn relay buss as a Bat+ feed source, and first year configuration for BATTERY gauge function.

Rich