Electrical Problem

[Barry N.]

The needle on my 1966 BB battery gauge fluxuates intermitently toward the + 40 side. It seems to happen more under heavy loads (headlights on). My 4 amp fuse blew one time while the needle was bouncing toward + 40 knocking out my dash lights (headlights stayed on). I don't know if the fuse blew because of an intermitent short or an over voltage condition. I also have seen the needle bounce toward -40 but no where near as many times as it pulses toward +40
Any thoughts would be greatly appreciated.

[Anthony S.]

Re: Electrical Problem

Barry,

My 68 was doing the same thing; I changed the voltage regulator and the problem was solved. Hope this is of some help.

Tony

[Jack H.]

Re: Electrical Problem

Fuses blow because they see too much current in the branch circuit they're protecting. Designers typically dial in a reasonable degree of design safety margin to avoid false fuse detonation....

Since the B+ voltage in cars of this era WAS known to fluxuate (in lock-step to the battery charging rate dictated by the voltage regulator), I'd conclude your problem is the result of intermittent shorting somewhere in the car's wiring system.

These are the WORST problems to find/fix because the trigger mechanism(s) come and go, sometimes the result of car-in-motion shock/vibration. My suggestion is to shop your neck of the woods for a competent auto electric shop to use for fault finding. This is where competence and prior experience can have a definite payback!

[Tim S.]

Re: Electrical Problem

Barry,
Pull apart the bulkhead connectors at the firewall (underneath and to the left of the master) to see if they are corroded. Clean them up and see if your problem improves. While it seems simple, I have found it can fix little problems as well as some major one and improve the electrical performance of the car. The voltage regulator could be hanging up like suggested. In addition, if those items do not yield any solutions, I would think about replacing the wiring or get it to someone that is comfortable
with electrical before your burn something up. Hope this helps.
Tim