C2 resistor

[Andries ter Hennepe]

Dear all, still searching for the overload in the electrical system. Could the resistor be the culprit? How does one check this item? Anyone any idea?
As usual, thanks in advance,

regards, Andries

[William C.]

Re: C2 resistor

resistor normally fails open, not short, so is unlikely to be source of your problem. As an aside, have you checked the ground to the voltage regulator? If voltage reg is not grounded, the alternator will build a slight charge under low load and then discharge as soon as a moderate load is applied.

[Andries ter Hennepe]

Re: C2 resistor

Bill,the problem is that the battery gets overcharged and boils.Battery is new as is the alternator, the regulator as well the wiring harness.Is there a possibility the ballast resistor doesn't do its job? Is there a way to test this?

[William C.]

Re: C2 resistor

Ballast resistor is not a part of the charging circuit. Your broblem is either the regulator or the alternator. If you inplug the 2 way connector on the back of the alternator, the charge should drop to near zero. Try that, if the charge level stays high, the alternator is defective. I forget what alternaot you have, but if it is the standard 693, full charge is less than 40 amps, and a combination of headlamps, Breaklights, radio, and full blower on the fan should pull it down to a very small charge. If it as a 55 amp alternator, it will take a larger load to work beyond full output, but check the alt first. if you disconnect the 2 way connector and you see a high charge rate, the alternator is definately defective. Once you verify the alt responds to the control input then we move to the regulator. By the way, while the connector is disconnected, if you jumper from the output terminal to the "F" terminal where the two way was plugged, it will go to full charge. That is how the charging level is regulated.

[Andries ter Hennepe]

Re: C2 resistor

Bill, thanks for the answer.You are very right on the ballast resistor, just found out on "ask jeeves".Let me enlighten the case a little bit more. 327/300 with 37Amp alternator and radio with electrical antenna (original).Now, I had to change the alternator 2 years ago and had the internals newly fitted but they installed a 42Amp.At the same time installed a new regulator.Does this explain?I'm not an electrics specialist...

[William C.]

Re: C2 resistor

Your are still in the same position, either the alternator is "self energizing". that is intenally shorted such that the output is partially being applied to the field to keep driving the alternator, or the regulator is not acting properly, either because of the wiring/connections to the alternator, ordue to an internal problem in the regulator. Is the regulator a Delco Remy "515" or an aftermarket item? the 515 is the correct unit for a C-2 corvette, regardless of the Alternator output rating. So let's check that the alternator responds to signal or lack of signal on the "F" terminal and start from there. If you email me your actual email address, I can scan you the test procedure from an old motors manual if that will help.

[Jack H.]

Re: C2 resistor

Just because the alt and v-reg are 'new' doesn't mean they're 'right' nor does it mean they're installed properly. You need an auto electric mechanic with mid-1960 American car experience to nail the problem as it appears you're not making progress on your own. There ARE Corvette specialty shops not that far from you who can 'talk' your Paris resident mechanic through diagnostics of the system.

If your resident mechanic is English speaking, try Claremont Corvette just south of London. Tel 0634 244 444.

For a 'form' of French assistance, try Corvette Garage Rob in Belgium. Tel 050 220 941.