Alternator wiring nightmare!!!

[gijoe985]

Alright, so I am helping my brother with his 8522r Toyota pickup. He originally had an 82 motor in it, and he had to get a new one and installed an 87.

Now, he has been having a nightmare getting the alternator to work. He just bought a new one, so we are assuming that the alternator is fine (though we may pull it and have it checked soon.) Originally he accidentally wired the main wire from the battery (to the alt) to ground and blew his 80a main fuse. After realizing that mistake, he got it wired up and the truck running. But he has never gotten and voltage from the alternator, even after replacing it.

Some of the problems we have encountered-
-The alternator has an E, F, and L written where the wires goes, which is different from the lettering I am used to seeing, and what the FSM shows. Any translations?
-We have a yellow, white, and b/w coming off the alternator, and a red, green, and black where it connects to the car wiring. We had to use connectors to get it in because the harness from the old alternator didn't fit the new.
-Now, the black and white wire on the alternator,(which we had hooked up to the red) is grounding out, so is it a ground?
-We just disconnected everything, but I think we were blowing the dash light fuse because we had the red wire hooked up to the b/w one.
-
Beyond that, we are lost... We've got the Chilton wiring diagrams and the FSM ones, but we are still at a loss... I even tried running a hot wire to each of ones to the alternator while it was running to see if it made it work...

Any ideas?

 

[2ndGenToyotaFan]

Have you checked voltage at the terminal on the alt when it's running? If you aren't getting 14.5 or so Volts there, then the alt isn't making juice for some reason... Have you checked all the other fuses after he blew the 80 amp???

 

[Bogo]

When did Toyota switch from external regulators to internal ones?

It may be easiest to get a FSM wiring diagram for the year of the alternator you got. Then wire it up to that spec with new wires.

From the colors you mention, it sounds like the wiring has been changed on the truck. An '85 should have 1 red, 1 yellow, and 2 white wires going to the alternator. My 89, 94, and 95 all use the same color scheme and I think it is the same one they have always used for internally regulated alternators on mini trucks.

Ground is done via the alternator case, no wire is used.

Check out the FSMs here: Toyota Tacoma/ 4Runner/ Tundra/ FJ Cruiser Factory Service Manual Page

 

[KLF]

When did Toyota switch from external regulators to internal ones?

8/84

My early '84 had an external regulator, when the alternator died on me I converted it to the newer style as it is slightly higher output. Besides the wiring change, you have to swap the bracket that bolts to the side of the block.

 

[Bogo]

OK, close enough. Could this truck be a pre external regulator one? Is it an '84 by production, and only purchased in '85? Another thing is the engine. It had an '82 in it for awhile. Could it have ended up with an external regulator alternator because of the engine and its mounting bracket? The other thing that doesn't fit with internal regulator alternators that I know about is the lettering by the plug on the alternator. I don't know what lettering is next to the plugs on external regulator alternators. OK, found a FSM for a diesel with external regulated alternator and the alternator has E, F, and N on the connector. Still not the same list. Looking further I see an internal regulated alternator that the connections to the regulator block inside the alternator are labelled E, F, and L. Could there have been a series of external regulator alternators that used that letter set for labelling the connector wires?

 

[gijoe985]

As far as I know it is internally regulated. Where are the external regulators located? Usually right on the alternator or on the fender?

I didn't get more than battery voltage when testing @ the alternator. But, if the regulator isn't getting a signal that the ignition is on, wouldn't it not tell it to generate voltage? That's why I tried hotwiring each of th3e wires going to it.

There is that one b/w wire on the alternator that is definitely grounded. At least when I tried hooking up 12v to it I got a nice spark show.

 

[Bogo]

If there was an external regulator it would be mounted on the fender.

I think we'll need to see some photographs of the alternator, connectors, etc..

We had to use connectors to get it in because the harness from the old alternator didn't fit the new.

Tells me you may have gotten the wrong alternator for the alternator electrical hook up present. Photos of both the old and new connectors would be good.

The next step will be to trace the wires, where do they lead to? At that point it may be easiest to just put in a modern internally regulated alternator, and make the harness it needs.

 

[KLF]

The external voltage regulator is a black box that is bolted to the inner driver's side fender. The alternators are very different, there is no mistaking them. The older non-regulated alternator has a bladed pulley, I assume to pull air thru the alternator as it is running, it looks kinda like this:

You can't even mount the non-regulated alternator in the regulated alternator mount, the spacing is different and the pulley location is very different, the belt won't line up. Besides the mount, I also had to swap over the entire alternator harness when I did my conversion.

 

[gijoe985]

You can't even mount the non-regulated alternator in the regulated alternator mount, the spacing is different and the pulley location is very different, the belt won't line up. Besides the mount, I also had to swap over the entire alternator harness when I did my conversion.

Well, I know that my brother said that the alternator off of his older engine (the 82) would not fit the bracket of the new engine he got. Maybe his old engine had the external type, the new engine has an internal, and he is still running wires to the old alt's regulator? There's a theory...

 

[gijoe985]

So I am assuming that the truck was previously wired for an internally regulated alternator. We just got and wired in an externally wired alternator. Should we buy an external regulator or find the correct bracket to switch back to an internally regulated one?

 

[84stockcrawl]

MMMM, I am in the same situation except I sold the truck and bought it back a few years later talk about a hack job. Test the alternator because when I did not ground to the side of distributer I had a nice melt down of the alternator internally regulated(almost caught fire you could see it glowing with power on). so I had to wire without a good plug on the back side of alternator and replace the big 60 or 80 amp fuse.
Since then (two owners and almost two years later) who knows what has been messed with. got the truck back almost a week ago battery light and e-brake light on. Last night took the multimeter all over it. 15 feet of junk useless and spliced wires removed and probably three shorts later no luck. So I asume the three years that this truck had to be over loading and shorting it finally damadged the rebuilt alternator?? testing that TODAY! We need the wiring diagrams mine is an 87 4runner converted to 22R.

 

[84stockcrawl]

***** bad alternator***** just got word from... well Napa, but still I belive the codes were right on. Plus after reading your problem I knew my rebuilt alternator could not keep a strong life with so many small wiring issues, Thanks guys! Good Luck gijoe985 I found our situations similar. The 1st time I shorted the entire alternator was in relation to this. It did not survive. Now I can back to cruisin'

 

[KLF]

So I am assuming that the truck was previously wired for an internally regulated alternator. We just got and wired in an externally wired alternator. Should we buy an external regulator or find the correct bracket to switch back to an internally regulated one?

Try to stay with the internally regulated one if you can. It is rated for much higher output, I think something like 80A whereas the older one is only like 55-60A. I can't remember the numbers, but it's worth the upgrade.