bosch alternator 1991 240 question

Hi all, My dashboard lights have come on twice since I've had the car. It happens only when I start the car and let it idle. As soon as the gas is depressed, they all go out. I searched for what it could be, and what I found was that it was pointing back to the alternator. I was hoping that after I rewired the Positive, ground, and the exciter wire, there wouldn't be any troubles. Six months ago, I replaced the voltage regulator and brush assembly. Belt is tight, no squeals, and the bearing is still 'good'. Drives fine, yet I wouldn't like to be stranded on a long trip.

Is this the sign of a soon to be failing alternator?

Thanks!

Had the same issue. Dying slowly. Will leave you stranded. Don't buy Autozone or any crap store reman. Buy a Bosch reman, a Denso, or go to a reputable rebuilder.

Make sure to check the regulator and brushes again though. Did you use a Bosch replacement regulator?

Thanks for the response, centason. I replaced the voltage regulator with one made by Huco. I would like to eventually get it rebuilt, or do it myself. However, it looks like the rectifier is the most expensive part at $150--almost as much as a re-manufactured Bosch alternator!

Can new diodes be purchased and soldered in?

Sorry for the reply to myself, but I checked to see if the battery light was on, today and it didn't even turn on in the KPII position most of the other lights did though).

I thought I remember reading somewhere that the battery light is needed in the circuit to assist in the charging process. Is this true for the later 240's?

thanks again!

Yes it's true for all 240s iirc. May want to check to see if the bulb is burnt out.

The lights staying on when starting and going off after revving up the engine is typically a sign of the charge light circuit not working. So I would check that out first before convicting the alternator. It may just be a bad connection or bad bulb.

The lights go out when you rev up because that causes the alternator to self excite and start charging.