Allan R

I'm planning to load up my car with power options and have already got a rebuilt 63 amp Delco Remy Alt for my project. So here's my question:
If I replace the 37 amp alt that's in the car now with a 63 amp alt, is is a straight plug and play installation, or does the voltage regulator need to be adjusted too? My gut feeling is that if I put in a 63 amp, it should work just fine and shouldn't affect the battery. If I understand the situation right, the higher amp alternator was needed for the high draw options to keep the battery from getting depleted.
Also, how do you adjust the voltage regulator if it needs to be done?

edzolz

Do it! Amps and volts are different. It will make your battery charge faster but put the same amount of volts into it.

Erinyes

Does your car have an ammeter gauge? If so, with an original 37 amp alternator, the gauge is probably +/- 30 amps, and a 63 amp alternator will make the gauge read funky.

If it's just a light, no worries. If it's a voltmeter, also no worries.

Lady72nRob71

There were only two regulators used in that year, one for rear defog and one for without.
Just changing alts should not require a reg adjustment, but it depends on what accessories were added. The adjustment procedure is lengthy and is in the chassis manual.
Changing to a solid state reg would eliminate the need to adjust.

You are correct on the need for a higher current regulator. The more electrical options, the more current is needed from the alt. However, power locks and windows and trunk and antenna are not really counted, since they are not run continuous - just bursts.

Changing a non-AC car to AC, or adding things like a rear defogger, powerful radio amp, seat heaters, or driving lights do require a bigger alt. 63A is even too small if you have everything.
If you had A/C and defogger factory installed, a relay was used to disable blower high speed when the defog was on.

Lady has a 63A alt which can get strained at times due to the amp and seat heaters, but I rarely use the fan on high in the winter.

TripDeuces

When my regulator on my Toronado gave out I bought the 37 amp regulator as a replacement by mistake and it fried on start up. If I remember right I had a 42 amp alternator and it did have a rear window defogger. I would buy a new regulator to be sure.

BILL DEMMER

iirc, there were 2 different regulators used. one for below 55 amp alternators, another for 55 amp and above. it may be as stated above regarding the rear defog, i can't say for sure. i would switch to the solid state regulator anyway, just for reliability.


bill

joe_padavano

Unless you care about visual correctness, I'd ditch the externally regulated system and swap in either a 10SI or CS130. The latter can be had in either 85A or 105A versions. Wiring changes are minimal.

Run to Rund

The parts book shows a different regulator for the big alternator vs. standard.

BILL DEMMER

i'd switch to a 12SI, why bother with the 10SI? a 12SI can put out nearly half of it's rated hot output, at an idle, the 10SI won't. don't forget to upgrade the output terminal wiring to handle the additional current, whichever path you choose.


bill

Run to Rund

In 1966 you could get 37 or 55 amp alternators; NAPA shows only one part number (VR142) regulator.

Allan R

Ok, it's a non AC car. No major upgrades have been done yet. The one thing that may have any effect is the electric defog on glass rear window. But that will not be on for anything since the car will NEVER be driven in fould weather or the snow again.

There are a number of other power options going in: PW, PDL, PSeat, P Trunk, Cruise, full lighting accessory harness, AM/FM Stereo c/w rear speakers and tape deck. Most of these should only be "burst" items right? Shouldn't have any major effect on my charging system. The ONLY reason I'm going with 63 amp is it was available as a new rebuild under warranty. I couldn't find a 55 amp in the same category or price.

I'm going to guess right now that my reg is one that is for 55 and less since the car was originally equipped with a 37 amp alt.

Ding ding ding, we have a winner! That's exactly why. I do care about visual correctness. I understand your comment about the upgrade to the 10SI - if I remember right that was being installed in Cutlass models toward the end of the 72 production run anyway. But my car is correct with an external reg. I just wanted to make sure that the 63 amp alt isn't going to do anything ugly to my charging system or battery. I don't expect it will after doing a little more research of my own, and listening to the feedback from the group.

Lady72nRob71

From what you just said Allan, the 63A should be perfectly adequate for your electrical needs, and look stock.
Upgrading to a solid state reg for reliability is a good idea, also.

BILL DEMMER

and it is likely a universal(not a bad thing) solid state replacement.


bill