TR4/4A voltage regulator - digital

[Sumton]

i have an interesting car; i am the third owner. the first two owners modified it quite a bit. alternator, no mechanical fan, lots of "interesting" wiring, etc.

it has a digital voltage regulator; i'm guessing from the 60's. it has a number on it: 038055. that's about all i can find. its just a black metal box with 4 wires coming out of it.

i don't think it is working correctly; i've just had the car running for a couple weeks, and both times after i ran it at night i had to manually charge the battery. if i don't use the headlights, its ok; no problems.

anyone have a recommendation for a replacement box? i saw this: https://www.brillman.com/store/prod...gulator-1914?gclid=CPi5l7mbzswCFQiQaQodvt4D1w

that seems like it would work.

thanks!

 

[CJD]

Digital? Not from the 1960's! You've got nothing to lose, so open it up and see what's in it. It may have a normal regulator that can be adjusted once the tops off. If not...then at least you have an idea of what the PO installed.

 

[Sumton]

did just that. its a circuit board. no telling! but i also found a two pronged clip loose in the engine compartment. should be hooked up to the alternator. that may be my problem. but i still want to replace this thing. i don't like stuff in the engine compartment that i don't understand!

 

[CJD]

It sounds like a solid state regulator, likely installed when the alternator was. Are there any dates on the alternator to get an idea of what decade regulator it might be?

 

[TR3driver]

Just to be clear, you must have a regulator that matches your alternator. The one you linked to appears to be for a Delco generator and will not work properly with ANY alternator.

Also, as a general rule of thumb, solid state regulators are pretty reliable. IMO your alternator is at least as llikely a suspect as the regulator. You might want to find a way to test it before just replacing it.

The vast majority of alternators today have internal regulators. My suggestion for your situation would be to just convert to a modern alternator and be done with it.
Another alternative might be to post photos here of what you have (especially the alternator) and maybe we can help identify what you have now.

PS what does your ammeter show?

 

[Sumton]

you want the whole story and pictures? Here it is. i got the car running, and noticed that the voltmeter was flivering (sorry - that seems to describe the motion of moving back and forth quickly to me!). so i replaced the voltmeter and the generator as a pair with 60 amp units. that did not change the flivering, except when we were doing some maintenance and forgot to plug the two prong plug back into the alternator. that stabilzed the meter, but it definitelly was on the discharge side. and of course we had battery issues. inside of the voltage regulator: https://www.ranteer.com/davescars/tr4/P1020419.JPG and bottom: https://www.ranteer.com/davescars/tr4/P1020416.JPG
the alternator: https://www.ranteer.com/davescars/tr4/P1020417.JPG

the unit that was in there was a match for an early 60's corvette. they are pretty pricey! so i went to O'Reilly's and said i wanted an upgrade for that, and they sold me this unit.

i'm guessing the flivering is due to the voltage regulator. i'd still like to replace it. but since i figured out the charging - its now on the positive side, i can at least live with it for a while.

and thank you, tr3driver, for pointing out that the replacement i had mentioned was for a generator.

 

[TR3driver]

My guess, the original 60s regulator was mechanical and that is a later solid state replacement. Looks very similar to the Ford unit I wound up with on my old Tr3 after the mechanical one finally gave out.
FWIW, O'Reillys will test any charging system on the car, for free.

 

[CJD]

"Flivering" is pretty much the normal mode for the ammeter. They don't have any damping, so they wag pretty fast all over the place!

 

[martx-5]

That alternator is a Delco 10-DN. It doesn't have an internal regulator. I'm assuming that the regulator is also a Delco.

Here's a pic of the 10-DN. It's clocked at 3 o'clock, yours is clocked at 12 o'clock.



Here's the regulator. The part number generally used for this is D9212. It's a solid state replacement for the original.



Both the alternator and regulator are from pre-1969 GM vehicles.

BTW, the Delco 10-SI unit can replace the 10-DN. The 10-SI has a built in regulator if you want to go that route. The mountings of the 10-SI and 10-DN are the same, and the pulleys will interchange. If there was any modifications to the 10-DN mounting, then you would have to do the same to the 10-SI, although I didn't have to make any changes to the 10-SI in my TR3.

 

[TR3driver]

I knew someone would recognize it!

BTW, you shouldn't see the ammeter jump around with an alternator & solid state regulator. The original mechanical regulator can, under some circumstances, cause the ammeter to jump around; because its switching speed will be slow enough to see. The ammeter also has a resonance where the needle will swing wider than the actual current change. But even that shouldn't happen at normal driving speeds. If it does, there is a problem of some sort (often dirty contacts or weak brush springs).

 

[Sumton]

incredible thanks to martx-5! i have ordered a new digital voltage regulator, and will keep the old on as a spare (and the old alternator). i hope i get the chance to buy you a beer (or more like a 6 pack) some time in the future! are you coming to vtr nationals this fall here in North Texas?

 

[Sumton]

TR3 Driver - the dirty contacts or weak brush springs - are those in the alternator? it's brand new, and the old one did it too. i'm thinking in this case its the vr, which is about to be replaced. or lousy wiring, which is a distinct possibility. you would not believe the rats nest the dpo left me.

 

[martx-5]

incredible thanks to martx-5! i have ordered a new digital voltage regulator, and will keep the old on as a spare (and the old alternator). i hope i get the chance to buy you a beer (or more like a 6 pack) some time in the future! are you coming to vtr nationals this fall here in North Texas?

Unfortunately, I won't be going to VTR this year. Texas is quite a haul from NY. Glad I could help out. I guess my thirty years in the automotive electrical rebuilding business came in handy. And here I thought I was through with all that now that I'm retired! :thumbsup:

 

[TR3driver]

TR3 Driver - the dirty contacts or weak brush springs - are those in the alternator?

Could be. But problems with the wiring can also show up on the ammeter.

Look for any quick connects that are the least bit loose. If they can wiggle at all, they may lose contact sometimes. Also make sure your ground connections are clean and tight, especially at the regulator.