LS1 Alternator Hookup

Thanks docwyte- nothing would surprise me at this point

Do you think that no voltage @ the blue alt exciting wire upon ignition is indicative of a blown (or MISSING) bulb? Assuming I even have the correct blue wire . . .

the first "how to'" I found on an 87 cluster removal looked like a PIA, but maybe that's just because of my current frustration level-

Maybe I will sort out the TACH while I've got it apart, but that's seems to a whole other can of worms with 50 different "right ways" to do it . . .

Onwards . . .

Hmm, that's not sounding right. Doc's suggestions are good. I'm afraid I don't know what to expect for voltage on that blue wire with or without the engine running. And my car's across town these days, still parked at the old house.

As for cluster removal, it's a pain the first time but gets easier. The wiring connector deals are the worst part, they have levers that clamp down to the back of the cluster.

Rich

Key on I'd expect the charge light to come on in the cluster.

Getting the cluster out is pretty simple, just a bunch of phillips head screws...

Docwyte- you totally called it! No bulbs on the bottom half of the tach.
None- looks like the previous owner wanted to make the check engine light
disappear ;(

Ordered some bulbs and hopefully when I plug in the empties all will be good.
Fingers crossed-

Thanks again-

Ugh- I replaced the bulbs on the back of the gauge, and still
No lights at all anywhere on the oil pressure/voltage gauge.

The volt gauge/needle is working though.

Any ideas? Issue with the circuit board on the back of the instruments?

Maybe I should give up and switch to a one wire set up.

Totally stumped . . .

Do you still have the factory alarm? Is it hooked up right? Did you hook up the blue charge wire correctly?

I tore out the alarm without much caution.
Could that have caused a problem with the power to the gauges
and to the blue wire? Now that I'm thinking about it, it would make sense that the
alarm would disable the ignition And associated switched circuits.


Already dealing with the fallout from cutting out alarm in terms of
releasing/opening the rear hatch . . .

I'm pretty sure the alternator is wired correctly to the blue wire.
However, when energizing the starter/ignition ON, the blue wire never showed
any voltage when tested-

Replacing the alarm and associated wiring seems like a huge PIA.
Wondering if it is as simple as splicing the blue wire back together if indeed I cut power to it when removing the alarm- or would I need to replace the alarm module? or just bypass? Ugh. Sounds like a nightmare. Wish i had better wiring schematics of that region.

Or maybe i just go for the one wire hook up and not care about warning lights.
But then i don't have the option of hooking up the ABS, and also there are convincing arguments about the inefficiency of a self exciting alternator.

Or, install the resistor that Painless spec's if not using a warning light? Or just install a 12v 2 watt bulb in line on the blue wire to replace the missing ALT warning light that excited the alternator?? Wouldn't that do the same thing as the alternator warning light that is in the gauge?

Hey Rich, did you remove the alarm or leave it? If you removed, did you do anything with the associated wiring?
Last thing I need to resolve before this baby is on the road-

Appreciate the advice-

J a s o n

The alarm and electric boot release were removed by a shop years ago when my car was made into a spec racer. I don't know exactly what they did but there's a bundle of wiring and relays zip tied under the fuse box. My dash warning lights all function normally.

Bummer on your continued troubles.

Rich

Ok, that's definitely your problem. That blue charge wire circuit goes through the alarm circuit. It also controls the rear hatch release on the late model cars and I suspect all sorts of other things.

I removed the alarm from my car and have the same issues as you. Luckily I didn't remove the wiring and harness plug, so I can just plug it back in.

On the late model cars the alarm bypass procedure on Clarks garage is wrong and you jump power to ground if you follow it. So on the 88+ cars you can't use it.

You can just loop the blue wire past the alarm circuit, but you still wouldn't have the rear hatch working...

Thanks docwyte-

Luckily I didn't remove all the wiring so I soldered the connector back in and jumped the pins as per
Clark's (I have an 87 n/a), and now I've got the alternator warning light glowing!
Yippee!

Now on to the hatch-

Thanks again for steering me in the right direction-

J a s o n

No worries. Wish the Clarks Garage bypass procedure worked for my car...

So the good news is that I finally bypassed the OEM alarm and the rear hatch opens with the key again.

The bad news is my alternator charge light on the instrument cluster still isn't lighting up.  I removed the cluster to make sure the bulb was there and not burnt out and it is there and isn't burnt out.

Ok, looks like the problem is how I've got the wire hooked up to the alternator then.  Someone confirm, the blue wire at the fire wall near the master cylinder gets hooked up to which pole on a 4 wire LS F body alternator again?

I used the pigtail from Painless (as per Rich L's recommendation)- worked great. I'm out of town now, but when I get back I can look at the pigtail's interface with the 4 pins on the alternator and see which post the blue wire goes to-