Alternator upgrade

Chris,
Sorry about the delayed response. Unfortunately this work gets done in the margins. No the bolt holes are not the same. The newer alternator definitely has larger bolt holes.
I am figuring I will need to get the old one rebuilt and I have a shop that is willing to try. Are they going to have issues finding parts too?
Best, Greg
 
I hope this helps others:
The Bosch AL655N was a great replacement for the OEM alternator on my '72 3.0cs in regards to fitment and alignment. One of the threaded bolt holes had to be drilled out to accept the slightly bigger factory mounting bolt and took less than a minute. The pulley had to be swapped over. We now have 14 volts at idle with AC Condensor Fan, Lights and Wipers on as opposed to 12 volts and the lights going dim. All with the comfort of a new "made in USA" Bosch alternator. We also used this plug for a cleaner install in regards to the D+ battery light wire.

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if you have to change things, i highly recommend the change to the newer style adjusting rod from the e30.
i used the 80a AL-46x with the e12 fan (12311350199) and the e12 pulley (12311362465), the bracket 12311274747, with the toothed nut 12317677914
 
I have what I suspect is an internally regulated alternator that I may have cockroached from a '81 528i that I parted out long ago, mainly for the 5speed trans. It is visually identical to the newer version in post #20. It has a reman sticker on it, over the (unreadable) original Bosch sticker. How can I determine its original identity and amp rating?

Can someone confirm that an internally regulated alternator needs the only a wiring connections are red to D+ via the ignition switch (and battery positive) , a ground from the alternator body to engine block, and wire from alternator D+ to the voltage regulator?
 
Stevehose said:
yes, bought an 85amp internally regulated one from BNR on eBay. It's been great for 4 years but just replaced it with another before driving to the Vintage, will keep the old one as a spare. Fits perfectly as it is rebuilt oem model. Run a D+ wire from new alternator to the D+ wire in the harness to the regulator. Tape off the other wires and keep the regulator in for orginality if desired.
Click to expand...
So here is the question of the day - i have a new internally regulated alternator and since i have my wiring harness apart to redo the lighting as well as replace the red wire between the battery + alternator (significantly chewed up), now i know why i kept having electrical issues in the past ... and i am doing some suggested edits suggested from @sfdon ... i realized that my car still has the original wiring harness for the external voltage regulator. so i was going to keep the D+ blue wire in place, as it eventually runs to the program tester plug. i am probably going to leave the external voltage regulator off of the car, so i will probably run a new blue wire from the D+ alternator straight to the program tester connector ... so it continues the circuit to the red (battery charge) light on the dash gauge. does that make sense to everybody? if i do that, i could just eliminate that plug out of the harness and eliminate the black + brown wire between the alternator / voltage regulator harness ... i will add a ground wire between the alternator and the body.

now for the next question - with a new external voltage gauge, what is the best location to connect the new gauge to? might as well run the new wire within the harness while its mostly open.
 
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