dmullin

I have An external regulator on my 70 442 455 4 speed. Seems that it should have internal being a 442, not a cutlass. 34487 vin, 455 sequence match, m21 match and build sheet.
Frame # matches sequence .
I realize all can be faked. Non w-30, a/c.
Production date was October 69.
Any enlightenment on this?

stevengerard

from what I have learned yes it should have been an internally regulated open-faced alternator - can't remember if AC necessitated the 63 amp or if it could have been a 37 amp. I think the 71s had both. What stampings are on the alternator? That should tell you if it was original or not.

lunaboy

for what its worth I had a 70 cutlass S 4 speed with the internal from the factory . oh and the internal harness is avail aftermarket if you find the correct alt.

Ozzie

For whatever it may be worth, the service manual says both versions were used. Page 12-12 has these applications:
37 amp. - A body (V-8 or L-6) non A/C
42 amp. - B, C, and E body non A/C
55 amp. - All cars with A/C
60 amp. - K81 (police option)
63 amp - C-49 (electric rear window defogger)
Page 12-25 says: "The Delcotron generator used on all 442 models has a transistorized regulator that is mounted inside the Delcotron." I don't have the designated parts book for 1970.

70Post

Ozzie - ???? - "both versions used"???

ALL 442's, in 1970, got the internally regulated alternator according to what you posted.

Were you talking about internal vs. external or 37A vs. 55A?

dmullin

I was wondering more about the reason why an "authentic" (so far as I know) 442 would have an external regulator with factory appearing harness instead of the internal that resto books call for?

stevengerard

Probably because someone swapped it I'm sure. They went back to external regulated alternators in 71 then I think in 73 or 74 all GMs got internal regulated again. I have seen a lot of 70s set up the way yours is. So many of these cars look "authentic" but just think, they are 43 - 44 years old. Who knows what happened to them within the first few years.

lunaboy

i would start with chking the harness from the regulater on the firewall forward to the engine harness on the rh fender . If the wire from there does not go into/ under the old 43 yr olds black tape within 12 inches or so of the harness, it may have been added/ spliced into an oem internal reg harness. Furthermore, this could tell you if the orig alt was replace. Very unlikely they replaced the harness also ... is what i am getting at.

Ozzie

As the manual applies to all lines of Oldsmobile cars produced during 1970, "both versions used" meant for the entire production, not just the 442. This might have been why some 442 restorations ended up with the externally regulated versions in place of the original internally regulated versions. Since, at that point, the discussion had already included capacity as well as regulation, I showed the capacity applications to help with identification. I did not have the original part numbers available.

joe_padavano

Actually, it was the 1972 model year where the 442s went back to the external regulators. 71s came with the internal regulators. As for swapping the internal to external, my 69 H/O had this done by a previous owner. It was not uncommon.