Which Bosch Alternator?

[Yadkin]

I am currently rewiring my '74 using a Painless #10102 harness and going by Bernie Seneway's Rev. C document.

On page 2 he mentions using a Bosch 55 or 65 amp internal voltage regulator alternator. Does anyone have the part numbers for these?

Thanks in advance.

[baltobernie]

I'm fetching my car from storage this weekend. I'll look for a part number and maybe a photo.
Feel free to PM me with any questions during your painful adventure

[Yadkin]

Thanks. The hardest part so far has been removing the old harness. Seneway said to remove it all in one piece. Simply not possible, and I have the dash completely out.

[Yadkin]

I built this last night to replace the original bank of relays on the left side of the engine bay. The 40amp resettable breaker will power the cooling fan and starter solenoid. The two self-resetting breakers power lo and hi beams. The bus bar is to consolidate all the grounds in that area.

https://drive.google.com/file/d/177W25e ... sp=sharing

This is mounted on a sheet of 1/4" thick HDPE, which I use to make panels like this routinely. The stuff cuts, machines with woodworking tools. Oner side is a matte black textured finish and the other side is gloss black. I cut a 5"x7" piece on my table saw. It has enough thickness to flush mount small screws. I'll put a blob of Goop Automotive on each fastener that is on the backside.

https://drive.google.com/file/d/1rvSDjg ... sp=sharing

(I'm not sure how to post images on this site.)

[baltobernie]

Thanks for your patience. My 65A Bosch alternator is p/n 0120489823. I think there are several Bosch part numbers for these alternators, used on the Spider from 1977-85.

I'm running my alternator (and water pump) from an undersized OE pulley. When rebuilding the engine, I had them cut the two larger pulleys from the casting. I didn't weigh the pulley before and after, but I was surprised by its original heft. My alternator runs at approximately crank speed, with an 88mm alternator pulley and a 95mm crank pulley. I have no issues with engine cooling or system charging with this setup.

[Yadkin]

Thanks for that. Rock Auto has a Remy rebuilt one for $45, including the $8 core charge. Autozone has a new Duralast Gold (lifetime warranty) for $99. Decisions, decisions...

[baltobernie]

Based on your earlier posts, and your willingness to take on this wiring project, I'm guessing you have experience in electronics, including the automotive version. You probably know that many "rebuilt" parts sold by big box stores are nothing more than bench-tested and painted before going out. If you live near a decent-sized city, you can probably still find automotive/truck electrical shops that actually rebuild starters and alternators in-house. I was surprised when I thumped my Marelli starter on such a counter. "No problem" said the tech. Fiat Allis (formerly Allis-Chalmers) uses this very boat anchor ... err, starter. Such local shops, and our vintage Spider vendors, are a valuable resource.
I've got 10+ years and counting on my locally-rebuilt starter and alternator in my Spider. The whole point of upgrading your Spider's wiring is reliability, which is only as good as the weakest component.

[Yadkin]

You aren't the first person who has said that about rebuilds. I've used them many times "back in the day" and never had a problem. Apparently workmanship isn't what it used to be.

My car only has about 57k miles on it and I have the original alternator and matched regulator. I'm going to clean these up a bit and rewire the car with those components and see how that goes. Thanks to your advice I have alternate plane should I need them. Plan B will be to rebuild those components and Plan C will be to buy the new "one wire" alternator.

My plan for this car is to keep it as original as possible except to upgrade the electrical. Once I saw that OEM fuse panel and the partially melted wiring around it that decision was an easy one to make. But I don't plan on big electrical loads like a big stereo or larger cooling fan. In fact I've already purchased a pair of Trucklite headlamps and those should be a reduction in amperage load.