Alternator and battery good, but no charge from alternator. 3Y engine 1985

[aelxon]

Hi guys, I got a new alternator(free under warrantee) and battery(old one was a crystler type with side terminals, which were exposed and I think shorted on the battery box frame!) recently for my 85' 3Y 2 wheel drive, but the alternator still isn't putting out charge(though when swapped into my 1986 van, it does).

With engine running, I volt metered from the plus/junction box to ground, got 12.2 V, then straight from the to-battery terminal on the alternator to ground, and also got 12.2 V. Rev the engine and this value stays the same. Nothing blown in main fuse box(haven't checked fusible links yet though)... thinking that this is a alternator wiring harness issue(based on reading older threads, and the fact that alternator and battery are good).

I have compared to my 1986 4Y van (both are 2 wheel drive), and one difference I have noticed between the two vans, is that the 1986 van has three wires coming out of the plus/junction box, while the 1985 only has two, and it is clear that the alternator->plus/junction wire isn't original in the 85'(not built into the harness like on the 1986, and made of red insulated wire, same gauge as the original on the 86'). Should the 85' van have three wires coming out of the plus/junction box, or is 2 the norm?

Before I get into the wiring harness, I figured I'd check to see if anyone knew immediately which wire/connection might be bad...or what else might be the culprit?


Cheers and thanks,

Alex

[aelxon]

Checked the harness today, 0 volts from the Black/Yellow(ignition) wire when the key is turned to on position, whereas on my 86'(no problem) van this wire reads ~12v. The pigtail is fine, so the problem appears to be somewhere in the harness, or in the ignition switch itself, or some fuse/connector in between?

Also noticed that with alternator pigtail plugged in, dash lights show on both vans, but with the pigtail unplugged, dash lights still show on the 86' van, but DON'T show on the 85' van with the charging problem...significance?

[originalkwyjibo]

I don't know if '85's are wired the same as an '88 but have a look at this post. Maybe it will be helpful. http://www.toyotavantech.com/forum/s...hts-at-startup I discussed an issue I had that may be similar starting in post #6.

[thetoaster]

That sounds all to familiar. Take a look at this thread. Start at post 20 and read it till the end. Hope that it helps you out a bit.

http://www.toyotavantech.com/forum/s...own-electrical