So, the shop that has my 1992 tried to charge my dead battery by running my engine. So now Im looking for a replacement.

I would like to go with a high output. So far online Ive seen Delco-Remy’s and Bosch’s.

Any recommendations on the way to go?

 

Keep the standard 120A Bosch alternator of your year. Or even just have your one rebuilt. The parts cost nothing. Bearings are like 10 bucks, rectifier is maybe another 10 etc.

These units are easily rebuildable.

 

Thats what Ive been tempted to do. Im concerned that one or more of the diodes may have been damaged. If so, finding replacements for them might be difficult

 

Even the diodes are cheap and readily available. I have a shop here in Germany where I bought my parts. They have the diodes too...

 

I have also been interested in getting a 150 amp alternator. In case I ever finally decide to replace my stock mechanical fan with a high output Spal

 

Spike
I am running the largest SPAL available, together with a 12 inch SPAL in place of the OEM electric fan, between them they are pulling about 43 amps. The 120 amp alternator does the job easily - the OEM 75 amp one does not. If you have a V12, in traffic the tickover will be a touch low to keep charging the battery if both fans are on. My mod was to wire the A bank extra air solenoid to the main fan feed, instead of to the aircon compressor feed where it is completely unnecessary. That way I can sit in traffic with both fans going full blast and the battery easily keeping the charge up.

 

The main killer of Alternators is heat, most die because they are caked with oil and junk, this reduces the ability of the alternator's rectifier and regulator to dissipate heat and they die.

I agree with the others rebuild the alternator and keep it clean and it will most likely last forever. I have the stock Bosch 120A alternator and my car still charges at idle with both thermo fans running and lights on. So the 120A is fine

 

I know the 120 works, but it seems like a good idea to go to at least 150. Who knows what is in the horizon as far infotainments or even electric fans are concerned.