1967 912 Red Light Question
 

Thanks to the professional help suggestions, I am waiting to hear back on a checkup appt. for my new 67 912.

One question I do have - the red light flickers and then often lights when idling, goes away when revved higher than 1500-2000. The prior owner said not a problem. Is this right? I assume something is going on that shouldn't?

Should I stop driving it until I can get it into a shop?

By the way, what a blast this car has been. Drove it 360 miles home through the mountains of WV/VA where it cruised flawlessly.

Thanks

The prior owner lied. That light comes on when the charging system isn't doing its job. Maybe you just have a loose fan belt, or maybe it's more substantial. Best bet is have it checked. Or, you can monitor your battery voltage with the engine running. I don't know the specs for your car, but it should be 13.something volts or more.

You mean the alternator light? If that was happening on my 3.2 I'd be worried the alternator was going. I don't know about on the 912 though. Kurt?

It is not uncommon for the alt light to glow at idle on an early car. It will depend on the idle speed and the value of the resistor applied to the charging light. If it goes out and stays out above 1500 I say you have no problem. Best to check the output with a multi-meter. You should start at 12.X V and then rise to a max of about 14V when the regulator kicks in tolimit the voltage.

Other sources of this aspect are bad (dirty) contacts for the alt., trans ground strap, and ground on the guage.

Jamie, that's odd. My alternator light doesn't glow at idle (900-1,000 rpm). Maybe I'm paranoid. I do hang around with RL! :shock:

Word on old cars is that a glowing alt light at idle is somewhat normal - basically there is not enough excitation current to the alt at low RPMs. There is a fix that involves (I beleive) putting a resistor in parallel with the alt light to increase the current. All of this info is stuff I read on the board researching my own alternator issues, so take it with a grain of salt.

Now, I just got back from the alt shop with the POS Valeo alternator from my Carrera. It, too, had the alt light glowing at idle and it was pronounced DOA at the shop.

Try the resistor first and see if that works. If no, pull the alternator and have it bench tested. You could have a ground problem, but I doubt it as that issue wouldn't typically be RPM dependent.

Chris:

Thanks to Dave Riley, I purchased a factory-rebuilt Bosch alternator for my Carrera from RPM in Newington about 2 weeks ago. Called in the morning, and it was at the shop for pick-up by 1:30 pm. Cost ~$260 plus a refundable $125 core charge.

’67 912s have generators not alternators.

J & J are both right, though J is more right than J. Generators equipped cars often show red at idle & though it doesn’t necessarily mean bad regulator or gen it isn’t right. Both need to be checked as does your fan belt, & grounds

The biggest benefit of alternators is that they don’t “run” all the time. The biggest benefit of generators is that they don’t need to be excited to put out :shock: Obviously car manufactures thought the extra HP was more better :D

funny, did you purposely try to use excited and put out in the same sentance?

Damn - you're psychic. I was going to PM you for this info. Thanks for the post - and sorry winstonbike for the mini-hijack of his thread.