Author Topic: Electric Gremlin  (Read 2034 times)

mikecio1

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Electric Gremlin
« on: July 29, 2018, 05:33:33 PM »
Hello all, I have a 67 RS with a 396, set up with a HEI 1 wire system. Internal voltage regulator alternator. I have never had any issues with it before, now it has developed an electric draw. Its a slow steady voltage draw, but so slow and slight its almost unnoticeable. However when you turn the headlights on the battery voltage goes into a heavy draw and the headlights go dim and start flashing causing the relays to click. I replaced the Horn Relay, headlight switch, high beam switch and the wiper switch. I disconnected the headlight doors to see if the draw was from there, it is not.
This occurs whether the car is running or not. If the car is running with out the headlights on, the battery will drawn down in about 15-20 minutes.
I have checked all the grounds I can find. I have even been touching all the metal I can to see if soothing shocks me LOL.
Does the alternator have something inside of it that could go bad and cause a constant draw or that could cause my symptoms ?
I am really at loss here.
I am open to all suggestions.

X33RS

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Re: Electric Gremlin
« Reply #1 on: July 29, 2018, 11:28:16 PM »
Sounds like a bad diode or diodes.  They'll cause headlights to flicker, and can also drain batteries rather quickly.   There is a very easy way to test with a volt meter.   Set it to a low AC setting and touch the probes on the battery terminals while the engine is running.  The volt meter should be 0 AC volts.  If it shows anything that's a good sign you have a diode issue.

You can buy them for your particular model alternator and replace, but for most they find it easier to just replace the entire alternator, albeit more expensive.