Alternator lamp wire not working, can anyone help!

[tristybomb]

Hi, I'm having trouble with the lamp wire to work in my ae86. Im wiring a 4age in, I've had the engine running but the alternator isn't charging the battery. I've doubled check the wiring to the alternator and I'm shore I've got it right. I used the [how to wire 4age thread] on here to work it out.

This is wants going on; when I connect the lamp wire from the fuse box to negative terminal, ignition on, not running, the charge light from the dash comes on. Indicating that it does work. When I plug it into the alternator. The charge light doesn't come on.
So maybe it's an earth from the alternator? I then checked the earth with a volt meter by using the positive wire to positive battery terminal to anywhere on the alternator and it reads +12v. So the earth is all good. I then check the lamp wire from the alternator and it reads +11v, by then putting the positive volt meter wire onto negative battery terminal it reads -1.85v, so that means there's power coming back through the lamp wire, is this normal?

So yeah I don't know if its the alternator is stuffed or its an earth issue. Or maybe something else. Can anyone help me out!!

[Matt]

The alternator earths out thru the casing / mounting bracket.

do you have the ign pin connected? 12v accessories plus 12v constant power for the sense wire

[tristybomb]

Yeah I've got the sense wire and the IGN wire hooked up. Just when I hook the lamp up it doesn't work.

[Matt]

Seams weird, it should just work. Especially if the light wire is providing an earth when the ignition is on.

That's how you checked it right? Red wire from multimeter to positive terminal and black to the light wire

[Matt]

Did you remove the regulator from the 4ac?

[tristybomb]

Yeah that's how I checked it. It only reads 11v though. Shouldn't it be 12v? All the 4ac reg is removed

[pt_y2k]

Pop off the alternator, pull off the 3 8mm nuts that hold on the back cover. Loosen the 10mm nut on the positive connection stud. Slide off the cover and take out the 2 Philips screws that hold in the brush box, use a good p3 Philips and catch it right once,they have a habit of slipping...out your meter across the 2 slip rings contacts and check for continuity, I bet there will be none there. Common prob on this end units is the rotor going open circuit thus no charge light.

[Matt]

Or u could send it off to golberg to be recod