C3 Electrical Problem

[Floyd B.]

Just completed a fairly thorough restoration of the engine compartment on a '73 and now I'm having an electrical problem.

When I first start the car the Ammeter needle is near +40 amps, but as the engine warms up the needle sinks and will eventually go slightly negative. The engine then starts to sputter and eventually dies. If I let it sit for about 30 minutes, the engine will start again and the ammeter is back up to +40 amps for awhile and the cycle starts over again.

The battery is new and the test machine at the auto parts store says it's fine. I thought the problem was the voltage regulator in the generator so I replaced the generator, but the problem remained unchanged.

When I go through the "Undercharged Energizer Condition Check" in the '73 Chevrolet Service Manual, Section 6 - Engine Electrical, pgs 6Y-20 and 21, step 5, I get the following results:

With ignition switch on:
Generator "BAT" terminal to ground = 13 volts
Generator #1 terminal to ground = 3 (three) volts
Generator #2 terminal to ground = 13 volts

I have not a clue on how to issolate this problem and would appreciate some guidance.

Thanx,

-Floyd-

[Jim T.]

Re: C3 Electrical Problem

First I want to clarify that I do not know what your electrical problem is. Since the problem may have occured after doing the restoration, I would double check everything that was disconnected and reconnected to ensure every terminal is wired correctly.

[Joe C.]

Re: C3 Electrical Problem

Floyd:

Three quick checks that might help:

1. With engine running, battery voltage should measure 14 plus volts (all accessories off, curb idle).
2. If you disconnect the battery with the engine running, then it should not stall. If it stalls, then you have a bad alternator, generator, or wiring problem.
3. You might have a poor connection at the starter, the fuse block, or ignition switch. Check these first.

Joe

[Joe C.]

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I meant to say regulator, not generator.