Red light on after car turned off

Prematurely bad Regulator...

The reg relay is supposed to drop out when the armature voltage goes below battery voltage. It's a fairly critical adjustment. Also, possible that battery feeding back into Gen will overheat the Gen.

Speedy Jim

76 van has alternator with 2 wires on it. Van has undergone PO's changes, I do not know if what I inherited years ago is correctly wired. There is a small one inch cube sealed circuit with about 5 terminals & only 4 wires screwed to the firewall on the battery side. Wires from battery, alternator, etc go to it.

What is the cube thingee if this is an internal-regulated alternator?

Red light came on while driving - intermittent - not like when one of the brushes wore out last year, but more steady. Wiggled the wiring and light went out and seemed to be okay.

The battery is not being charged. Worked okay till recently. Can drive for a day or 3, then I must recharged the battery in the shop. No big deal, but it doesn't last long if I drive at night.

Alternator brushes okay, but there was a lot of fuzzy shit around them that could have been shorting something out till I cleaned it out.

After this, it seemed to not be charging at first, then light started going out [properly when started, but I'm still unning on the battery. I get about 12.3v at alternator - no increase when running faster.

How do I test the alternator (Jim's site has gen only?).

Where were those wiring digrams posted?

Any suggestions for easy fix? I have another alternator - a 3 terminal one, but if I put it in the car it behaves like an electro-magnet, probably because when I tried it a year or 2 back I forgot it needs the external regulator. I'd rather not change it - just get my installed one working, although it's no big deal for me to change the alternator in the van - I got Kadrons, but I think I've thrown out all the old spare external regulators!!??

Any suggestions - Jim? Travis?

- Tom

Got it.

Had a coupla those cube thingees left in the spare bits bin, so I changed it out and now I'm back in there competing with Con Ed.

Got 13.8 volts at the post - oops - I'd better go back outside and check that it's getting all the way thru to the battery.

I'm guessing that cube is a relay/switch device to take the alternator out of the loop when the starter's cranking the engine, so's not to be pushing things uphill. Mine had lost it's memory, and forgot to put 'er back into the loop afterward, or something like that.

The terminal numbers involved are:

30 (ground?) 85 86 coupla 87's

The diagram on the outside of the one I took off definitely has it pegged as a relay of some sort.

Any confirmations on exact identity & function of this part?

relay of some sort.

Yes, it's a relay. Used for a variety of things. I have a diagram on my web site here:

for the rear-window defogger.Shows the terminal identity. Speedy Jim

Jim

What might the other uses be, do you think, in a van which never had a rear window defroster in it?

I'm more interested in why/how my alternator now works, whereas before I replaced this relay it did not work.

Tom

window defroster in it?

replaced this relay it did

Truth be told, I don't have a clue. Only thing I can think of is some dual battery setup for camping, but that relay doesn't seem appropriate. I guess you could carefully trace each wire and make a diagram...

Speedy Jim

Rings a bell. The PO had an air con in there, and there was a dual battery setup, but it had it's own alternator - 2 completely separate systems. I threw the whole mess out and put a little fan on the dash as soon as I got the van. Poor little engine ran it's heart out trying to turn everything 'cept the wheels. Took about 500 lbs. off the vehicle weight that day.

I'll make a diagram and figure it out.