Replacement Alternator Question

[fhpete]

Hello Experts,

I need a to replace my stock alternator (1973 CS) with an internal VR type.

I have a local shop that can do the work - but they've asked me to source the right replacement alternator.

From what I can deduce from other threads, I should be sourcing an E12 alternator if I want it to bolt into the stock mounts. This will be a 65A alternator with an internal VR. Correct?

If I want one that bolts into the mounts of the old one - what should I be sourcing and can anyone point me in the right direction on where to get it?

The symptoms are:
- battery acid rusting a freshly painted lower engine bay
- burnt/smoking wire casing of a black wire coming out of the stock voltage regulator
- car wont start with the short that results from the above melted wire (don't worry - I stopped trying to start it after I saw the issue)


Thank you for your help.

Pete

 

[61porsche]

Internal Regulated Alternator

Yes, the E12 is 65 amps, internal. Source should be local parts store; it's not difficult to find or order. Bosch 65 amp, Keep your pully , nut, key , etc.

 

[HB Chris]

The burnt/smoking wire is probably because the three wires from Alt to Regulator have lost their insulation and are shorting out. This is extremely common. You might try replacing the three wires first.

 

[fhpete]

Thanks

I will take a run at replacing the wires. Because of the battery acid leak, I had assumed it was an alternator issue.

I also now have a solid idea of which alternator to source.

Thanks guys,

Pete

 

[jmackro]

Pete:

If you do decide to install a higher amperage, internally-regulated alternator, you could order a rebuilt unit from bnr parts. They sell on ebay - see listings like: http://cgi.ebay.com/ebaymotors/BMW-...r_Truck_Parts_Accessories&hash=item519339b349

I got an internally-regulated 65a unit from bnr a few months ago. It just bolted in, and the wiring change to eliminate the external regulator was pretty simple. Call bnr's 800# ; the people there seem to understand what is needed to put a later alternator on an early BMW.

 

[HB Chris]

I used them as well, they seem to know older BMWs, and put in an 80Ah unit. I did have to swap the pulley from the older Alt to have PS belt clearance.

 

[fhpete]

Thanks

Thanks for your help.