Alternator wiring question

[slovanova]

Can anyone tell me where each wire goes on the stock alternator on my 86 SVO? I just got done swapping the head gasket and the car will not stay charged. I am not positvie if I put the wires back on right. I have a feeling it is the wires cause it all worked when I took it apart.
Thanks in advance for any help.

[GAboySVO]

When my battery would not hold a charge, the problem turned out to be the voltage regulator.

However, just to confirm the wire layout:

The brown wire goes to the top terminal.

The black wire goes to the middle terminal.

The orange wire goes to the lower terminal.

[KevinK]

Your typical alternator is not made to recharge a weak battery. To accurately test the whole system, you need to start with a fully charged battery. Most batteries are about 400 amps, so you need to put 400 amps back in it. The best way is slowly like at 2 amps per hour. At this rate it will take 1.5 weeks. You can do it faster but it is harder on the battery.

Next, put a volt meter on the battery before starting the car. It should be about 12.5-13 volts. Start the car and you should have more, 13-14 volts at the battery. If that is the case then everything is working.

Turn on everything electrical (lights, ac or heat on high etc.) and watch the meter for about 15 minutes and it should not continue to drop the voltage. It will drop a bit at first but it should hold there. This will tell you if the alternator puts out enough.

[slovanova]

OK, I am going to take the alternator to get it tested just for the heck of it. When I put it back on, I will make sure all the wires are on right. I might also pick up a voltage regulator. I have the battery on the charger now, so hopefully it will work right.

[slovanova]

OK, I got it back together. I had the alternator checked out and it was good. I also put a new voltage regulator on the car, but it still doesn't work right. Here is how I have the wires on the back of the alternator:
Black/orange (big wire) -----> BAT
Yellowish wire -----> STA
Orangish wire -----> GRD
There is also a terminal marked FLD, but if I connect the orange wire to it, nothing changes. The battery voltage was 13.2 with the engine off, but with the engine running the voltage was like 12.2 and slowly dropping. Do I have the wires on wrong or what?

[Rob Jakos]

why not upgrade?

I rescently upgraded to a 130 amp alt in my SVO and I tell you what, I'll be damned if I put that 60 amp back in again!

I bought mine off e-bay and was able to get wiring schematics here on SVOCA!

You won't be disapointed...

[GAboySVO]

This is how mine is:

Black/orange (big wire) -----> On terminal closest to valve cover

Yellowish wire -----> Has black rubber cap and goes to the terminal at the top with black plastic terminal marker.

Orangish wire -----> Has red/org rubber cap that goes on the bottom terminal with the red plastic terminal marker.

Hope this helps.

[slovanova]

I am stumped and this is driving me nuts. The wires are all in the right spots, and the regulator is new, but it still won't charge. How hard is it to trace all the wires that go to the alternator? I think I may just go ahead and upgrade to the 130 amp alternator though.

[slovanova]

Well, I tried connecting the wire to the field post and it still didn't work. I guess I will just trace all the wires and see if there are any broken or burned up. Or maybe the alternator is bad and the guy testing it didn't know what he was doing.

[KevinK]

Most of the wires go directly over to the battery/starter relay or the voltage regulator. One probably goes to the dash instriment cluster for the Alt. light. Make sure the voltage regulator is grounded well.

[SVOeric]

Make sure the voltage regulator is grounded well.

This is a GOOD suggestion -- I have had problems with this in the past.