I need help identifying this wire that come out of the plug on the alternator, the car is my used 98 cobra. My alt. went out 2 weeks ago i take it to a shop for a rebuild he said i could exchange it for one off the shelf. So i run mine old one up there and he tell me its off a mark 8. I dont really think nothing of it cause they are both DOHC motors. He gives me the correct alt for the cobra which looks more like the one i had just put on a 98 cobra i had sold a few months back. I think a simple swap and im good. but i notice as im plugging the harness back in the new alt that this middle wire (white with a black stripe goes no where and its looks like it was cut and stuffed into the loom. I dont know if the Cobra alt needs this wire connected or i just got a bum ass re-built alt from this dude. The only reason i say that is because the alt was charging then not charging then charging again then finally my ass got stranded trying to take it back to him. So if anyone can run out under shier hood and please help me find where this wire is supposed to go i would be eternally grateful. THX Jason.
Alternator help
- Thread starter jperez77
- Start date
I need help identifying this wire that come out of the plug on the alternator, the car is my used 98 cobra. My alt. went out 2 weeks ago i take it to a shop for a rebuild he said i could exchange it for one off the shelf. So i run mine old one up there and he tell me its off a mark 8. I dont really think nothing of it cause they are both DOHC motors. He gives me the correct alt for the cobra which looks more like the one i had just put on a 98 cobra i had sold a few months back. I think a simple swap and im good. but i notice as im plugging the harness back in the new alt that this middle wire (white with a black stripe goes no where and its looks like it was cut and stuffed into the loom. I dont know if the Cobra alt needs this wire connected or i just got a bum ass re-built alt from this dude. The only reason i say that is because the alt was charging then not charging then charging again then finally my ass got stranded trying to take it back to him. So if anyone can run out under shier hood and please help me find where this wire is supposed to go i would be eternally grateful. THX Jason.
Well, I just checked on my '97 Cobra. It has three wires coming out of that connector and going into the wire harness.
It's dark out and i didn't look to see the colors because I have the service manual on CD. The colors are: Black/Orange, Violet/White, and Light Green/Red. There is no Black/White wire connected to a Cobra alternator. Maybe, due to age and dirt, your Violet looks Black? V6 and SOHC V8's have a different alternator with a black/white wire that is nothing more than an external jumper between two internal components of the alternator.
Thing is, all three of your wires should go into the harness. Somehow, someway, somewhere, your third wire (be it Black/White or Violet/White) has been cut or broken off a few inches into the harness. Peel back the tape and find where it was cut/broken, and splice it back together. Wouldn't surprise me at all that you find that all three wires are spliced (for some long lost reason) inside the harness. From your intermittent charging condition the connection down inside the harness itself was probably intermittent, and you really didn't need another alternator!
Good luck!
Sankeye I appreciate the quick reply, I went out and started to peel back the cover on the wiring all the way back to the main harness going back about around the battery. I also double checked the wire colors its for sure a white wire with a black stripe(its the center wire on the harness). Anyone with a 98 please if you got time and light try to see if this is what you have on your car. So at least i know some joker b4 me maybe installed (spliced) in a SOHC harness maybe.
Now that it's daylight I'll take another look just to confirm the colors of the wiring diagram.
Thing is even the SOHC alternator uses the same three wire color combinations PLUS the Black/White. And I don't think a SOHC alternator would bolt up to the DOHC engine.
If you didn't find the third wire in the harness something is really wierd.
Thing is even the SOHC alternator uses the same three wire color combinations PLUS the Black/White. And I don't think a SOHC alternator would bolt up to the DOHC engine.
If you didn't find the third wire in the harness something is really wierd.
Yeah i know very wierd since the old alt was working just fine till it went out and i had it replaced. Thanks alot for looking though.
Guess what, my alternator connector has a white with black stripe in the middle position just like yours! And, just like yours, it goes into the harness 3-to-4 inches and ENDS! Unlike yours my passengerside wire is black with green stripe. And like yours my driverside wire is yellow.
So, the good news is your wire is okay.
Let me check the wiring diagram again for wire colors and fuses that are associated with the alternator.
So, the good news is your wire is okay.
Let me check the wiring diagram again for wire colors and fuses that are associated with the alternator.
Okay, here's the deal. The three wires on the diagram include the big heavy one bolted to the stud next to the plug-in connector, so only two of the three wires of the plug-in connector are used. Which we have seen for ourselves.
Which gets us back to solving your alternator's inability to charge. So, take a look inside the engine compartment fuse box for a 20-amp fuse which should be labeled (look inside the fuse box cover) "alternator". From the wiring diagram it appears to provide voltage output feedback to the voltage regulator and to the field winding of the alternator. If it's blown: no voltage to the field means no output from the alternator.
Check it out and get back.
PS - Just stuff that white/black wire back into the harness and forget it. It apparently has a use with the alternators on SOHC V8's and V6's.
Which gets us back to solving your alternator's inability to charge. So, take a look inside the engine compartment fuse box for a 20-amp fuse which should be labeled (look inside the fuse box cover) "alternator". From the wiring diagram it appears to provide voltage output feedback to the voltage regulator and to the field winding of the alternator. If it's blown: no voltage to the field means no output from the alternator.
Check it out and get back.
PS - Just stuff that white/black wire back into the harness and forget it. It apparently has a use with the alternators on SOHC V8's and V6's.
Thx again snakeye its I checked the fuse and we are goo there so this new alt just must be bad. its charging when its cold (right after a start up). After the car warms up its starts to not charge. I went ahead and replaced the battery cables just as a precaution and had the battery checked and charged up at autozone but still the same thing. So I really appreciate you looking into the wiring for me but clearly this is my rebuilt alt. Now I got to recover all the wiring i took out the harness....:uh oh:
Now we're getting somewhere: bad voltage regulator.
I had an intermittent one. I could tap on it with a screwdriver handle and switch it on and off!
While Ford says that the voltage regulator is not replaceable, and the whole alternator needs to be replaced, it is. I got one from a local generator and starter motor repair service for $35. Plug and play.
I had an intermittent one. I could tap on it with a screwdriver handle and switch it on and off!
While Ford says that the voltage regulator is not replaceable, and the whole alternator needs to be replaced, it is. I got one from a local generator and starter motor repair service for $35. Plug and play.
See and thats where this alt came from was a local generator repair shop, it was cheaper then going to autozone.
I wouldn't fault them - yet. If the voltage rgulator is intermittent they'd never see it in a bench test. It needs to get heated up, maybe even with engine heat to really heat it up. Get'em to swap the whole alternator or replace th VR.
When im off this weekend thats first on my list of things to do, thx again.
You don't need it on the cobra. Idk about the mark 8, but I just did a cobra swap in my GT. the GT alternator uses that wt/bk wire, the cobra doesn't. Just plug the connector in and stuff that wt/bk wire back in the loom. Mine works fine.
I replaced the alternator after the shop I got it from tested it again. He put more load on the alternator and it wasn't charging correctly. After replacing it the alternator worked till I sold the car.
Actually the sohc harness will bolt up it does so without a problem except the jumper wire that i just leave hanging there. Whats that wire for though
seems possibly my intermittent battery light that only comes on when cold, may be a bad alternator or VR. checks fine hot. I have a spare alternator from my 99 Crown Vic CVPI that is gone, I am wondering if it will work even though the three wire plug is in a different location on the alternator. I saw on one parts site the same part number for both cars, but again, the plug is in a different location and I have not checked to make sure the plug is exactly the same, but looks like it. the cobra has the black and white wire in the middle, the Crown Vic plug does not have anything in the middle.
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