josh88

ok, this is really starting to make me mad... I have a 94 22RE Toyota from Cali, and it wont charge.. ive changed the alt 3 times, did the ohms test from battery to alt, checked the 80 amp fuse.. i get 12 volts at the alt... but some thing keeps burning out the alt's.. as ive put one that i new was good on it, and just bought a new one... and still wont charge.. ive checked all the grounds... My charge light wont come on inside the cab, and i have no gage.. what would keep burning out the regulators in the alt... i did know the truck had been is a small crash b4 i bought it... so i started looking around and found that the metal tab that holds the wires going from the alt to the battery had ben bent over on to the wires and had been chafing.. so i changed that small section of wires... and i get a good reading at the alt and battery of 11.98.... so where else could i go.... and i put the new alt on after i changed the wires cause i figured i had found the problem... i have a BRAND NEW Toyota engine in it with 1000 miles on it... so i have 3300... bucks in this truck and i cant drive it... and its making me want to just send it to the crusher... ive had atleast 25 Toyota pick ups 89-94 and NEVER had a problem like this..... any help would be greatly appreciated

josh88

some body must have a lil help..

josh88

help!!

josh88

ok now i tour the dash out of it.. and the light bulb is good for the charge light.. but it wont come on... there is power and ground there.. its so weird... has anybody had this kind of problem.... nest thing is going to be to change the whole wiring harness in side the truck... that sounds like a night mare....

some one plz help!!!

josh88

nobody has 2 cents.... or even one

bugs1961

Here is the FSM wiring diagram for the charging system: http://www.ncttora.com/fsm/1990-1995...i/charging.pdf

With the engine off but key on:

Check the fuses in the diagram first. If they are good, and you have 12v at pin 4 (yellow wire) of the combination meter connector, use a piece of wire to ground pin 4 and the light should come on. If not, the bulb or combination meter has a problem. If it comes on, then the wiring to terminal L at the alternator is bad. Connect a test piece of wire from pin 4 to terminal L and the light should come on. If yes, fix the broken wire or run a new one. If no, the alternator is bad.

This site has great articles on how the electrical system works: http://autoshop101.com/

Click on "Technical articles"

Click on "08 Charging Systems"

If you get the light to work but still don't have any charging, I would temporarily install new wires to the other terminals of the alternator in accordance with the wiring diagram. I would use 14 ga wire for the IG and S terminals and 10ga direct to the positive post of the battery for the B terminal. This is temporary, just long enough to determine if the alternator will charge with new wiring!! Check the size of the OEM wires before making a permanent rewire.

Good luck,
Bugs

wyoming9

iTrader: (1)

First off when you say you checked the grounds what do you mean ?? How did you check them??

The first thing I do on these trucks or 4Runners is replace all the grounds with new cables using #1 welding cable . One cable to the body one cable to the engine block.

Check the plug that goes in the back of the alternator I have seen them corroded not so much to see but enough to cause the problem. With the charge light not working that could be the problem

Another thing to look at is the condition of the wire coming off the B terminal of the alternator running up to the fuse block. Being that they get cooked over the years and don`t work as well .

You do have the battery charged when you install the alternator .

You replaced a few of them and they never worked a string of bad alternators where did you get them where they checked when you took them back or just exchanged???

Hope maybe something helps.

ovrrdrive

I had that problem once and it ended up that the plug had come off the alternator down below. I plugged it back in and the lights came back on. I suspect that your wire or plug is bad somewhere. Have you taken the alternator off and had it tested?

josh88

ok, thanks 4 ur replies guys...

Wyo: I took all the grounds off and sanded the ends then put them back on.. i also added another ground to the alternator.. and my friend has a 2 way test light.. and we checked and there is ground at the ALT ground wire...

ovr: its not the plug being unplugged... and i took a alt of a running and charging truck put that in and nothen... but being a had a bare wire that was fixed( read above ^) i was thinking i might have burnt out the regulator.. sooo... i went and bought a brand new alt.. with it having the same problem... sooo... i took that out and took it back to the parts store and had it tested and it worked fine...

so i have no clue what to do.... im going to look at the diagram that BUG gave me and see what i might find..

but any new info would be great..

what would i have to do to rewire the whole charging system??? does it have to go threw the inside of the truck? or can it all b run just in the engine bay for good??? no need for a dummy lite or a gage if i really dont need it..

scope103

For what it's worth, a reading of 11.98 (or 12.0) is not good. With the alternator turning you should get about 14.1 volts. It sounds like all you are getting is battery voltage (and even then 12 is a little low, but that depends on temperature).

You might try disconnecting the B cable (the big one) from the alternator, then measuring the voltage at the alternator when the truck is running. If you get 12 volts (or zero) then the alternator is not putting out anything (it should be about 14.1).

The lack of a charge light (key on, engine off) usually means that you are not getting 12v TO the alternator in the first place (or the alternator is broken internally). You could disconnect the smaller connector, and check for 12v on the three wires (you should get 12v on all three, but according to my diagram red and white connect direct to 12v, the yellow connects to 12v through the charge light.) Then try connecting the yellow (not the fat one, the one in the small connector) to ground, which should light the charge light.

There's nothing wrong with replacing all the big fat wires and checking the grounds, but from what you've described so far the problem is elsewhere.

josh88

is it possable for the problem 2 b in the spedo cluster?? as in the mother bored...

abecedarian

like mentioned, with the engine running 11.98 is not a good reading at battery or at the post on the alternator- should be more around 14-14.5 volts at the stud on the alternator.

On the 3 wire plug, check that you have voltage equal to battery voltage:
... on the white wire at all times
... on the red wire when the ignition switch is on
... on the yellow wire when the ignition switch is on

Check that the 7.5 amp "Charge" fuse is good.
Check that if the key is on and you ground the yellow wire the charge light comes on and doesn't blow the IGN or CHARGE fuses.

josh88

should be 14 if its charging.... but its not!

when checking the red and yellow wires for voltage.... do they have to be pluged into the alt? ovaslly for checking 4 the 14 volts.... but what about the 12 volts from the battery?

abecedarian

nope. you're checking the voltage at the plug, without it plugged to the alternator.
the red and yellow wires come from / through the ignition switch and dash cluster.
those wires should have about the same as the battery voltage.

josh88

ok thanks... i will check them 2moro..

josh88

if the 7.5 amp ing fuse is bad, or the 10 amp engine fuse is bad.... it wouldnt run at all right?????

abecedarian

How about you tell us what you find and we tell you what we think? just kidding.

However, if those fuses are bad, it shouldn't run.
How is the Charge fuse?

josh88

all the fuses where good... i think its the spedo bored.. it shows a pic of a resister and i think its bad

josh88

wasnt the speedo board... i changed that also..

josh88

I hate this truck and dont know where to go next! HELP PLZ.... ok i tested all wires going to the alt with a test light.. i have power on a 3 wires going to the alt.. i grounded the yellow wire and the battery light finnaly came on.. i tested the big wire that goes to the battery.. and thats good also... i then tested the grounds.. and the test light comes on... all fuses are good... so i then take tha alt out and put it in my other truck to make sure that it shares and it starts to charge.... so what else could be my problem... im pulling my hair out...