I'm an IDIOT!

[cjkeeliii]

OK, so alternator # 2 seizes on the way home. I get it rebuilt. I hook it back up. BACKWARDS! When I hooked the batterys back up, a loud pop and a puff of smoke come out of the alternator. Question: Even though I fried the alternator, shouldn't the GEN 2 idiot light still shine before I crank the truck? It did before this incident. Have I fired something else, and where is this something else? Checked the GEN 2 bulb, and it's fine.

 

[Screamin' Metal]

Nope and yep....respectively.....

 

[gaunt1969]

It is prob just that you fried the alt. if you pull the plug on alt1 you will notice it does not come on either. dont worry about the light till you get the alt rebuilt.

 

[twright]

Check the fues link at the bus bar that is right above the glow plug relay
AEC Retired Tony

 

[stampy]

Don't feel bad I backed into the wifes 2002 7 series BMW this morning with my 84 300sd (windows were iced up) Bang! big dent in the drivers door...no damage to the 300 sd. I will never hear the end of it.......

 

[southdave]

7 arn't cheap how did the Merc fair

 

[cjkeeliii]

Thanks for the replies. As suggested, I pulled GEN 1's wire and it didn't light. Made me feel better. But, I did try to crank the truck without alternator 2 in place: won't try that again. Lots of sparks from back battery's positive terminal. Maybe I'd better read up on vehicle electrical systems.

 

[stampy]

The 85 merc had no damage! the 7 series......$400$ est (and I think he is letting me off easy as he knows me)

 

[southdave]

Thanks for the replies. As suggested, I pulled GEN 1's wire and it didn't light. Made me feel better. But, I did try to crank the truck without alternator 2 in place: won't try that again. Lots of sparks from back battery's positive terminal. Maybe I'd better read up on vehicle electrical systems.

yeah thats pretty good start, I went to kinko had them Plot the PDF on E-size paper 2.00 buck a sheet little big but made life easier maybe try C-size.


Stampy- Had 98 il the damed alt. was 800 bucks first time i ever saw a water cooled alt. love the car although it was a pricey wentch, I had till last summerr 300 sd heated seat an all the crap bamdi did it in. The motor is (poorly) in a 90 for ranger.

 

[cjkeeliii]

I need some serious help. The shop that rebuilt my alternators said that alternator 2 was OK. I hooked it up--CORRECTLY-- then hooked up the baterries, and got a sizzling/frying sound from the back battery's negative terminal, and smoke poured out of the glow plug relay on the firewall. I've never had any electrical trouble with this truck. I know nothing about vehicular electrical systems. HELP!

 

[sparky1]

I need some serious help. The shop that rebuilt my alternators said that alternator 2 was OK. I hooked it up--CORRECTLY-- then hooked up the baterries, and got a sizzling/frying sound from the back battery's negative terminal, and smoke poured out of the glow plug relay on the firewall. I've never had any electrical trouble with this truck. I know nothing about vehicular electrical systems. HELP!

i suspect your rebuilt alt was rebuilt incorrectly for your vehicle.that single stud in the lower left corner of the alt must remain an isolated ground.if the alt shop grounded it the sparks will fly.been there done that.

 

[gaunt1969]

Easy to check. Take a VOM and check for continuity btween the ground post on the alternator and the alternator case. If you have continuity they got something wrong. Ie they built it for a 12V system. A 12V system ground is usually the alt case.

 

[cjkeeliii]

Would that also explain why the GEN 2 light would not light up? Should the passenger alternator be wired like the driver's side? Any pictures would help. I looked at a picture of the passenger alternator on the Roscommon Equipment Center website, and the picture shows how I originally wired my alternator when I thought I had wired it backwards. Dazed and confused. Now it looks like I really do have it wired backwards. TM's wiring diagram kind of fuzzy to me also.

 

[sparky1]

Would that also explain why the GEN 2 light would not light up? Should the passenger alternator be wired like the driver's side? Any pictures would help. I looked at a picture of the passenger alternator on the Roscommon Equipment Center website, and the picture shows how I originally wired my alternator when I thought I had wired it backwards. Dazed and confused. Now it looks like I really do have it wired backwards. TM's wiring diagram kind of fuzzy to me also.

on my m008 the isolated stud on the drivers side gen grounds directly to an intake stud. however the passenger side has one red wire that goes back into the harness and ends ??????

 

[cjkeeliii]

yes, mine seems to be like that, but should alternator two's wiring hook up to the alternator exactly like alternator one's? i told the rebuild guy the alternator needed to be isolated ground, and i think he said he rebuilt it that way. who knows?

 

[sparky1]

yes, mine seems to be like that, but should alternator two's wiring hook up to the alternator exactly like alternator one's? i told the rebuild guy the alternator needed to be isolated ground, and i think he said he rebuilt it that way. who knows?

i believe out of the vehicle the two alts are identicle.they will interchange from left to right and right to left.the only thing different is the wiring.i don't have the experience to explain it.i do know i had a bad time years ago when we sent a military alt out to a rebuild shop.we installed it and were hooking up the last battery,the sparks flew like someone was arc welding.thats how i found out about the ground.i have wiring schematic at the garage i could copy and send to you.

 

[cjkeeliii]

just unhooked the passenger alternator, and hooked up the batteries. no popping, frying, sizzling, sparking, etc. logically, i must conclude the alternator is flawed. now if i only had a voltmeter.

 

[cjkeeliii]

sparky1, that diagram would be great

 

[cjkeeliii]

gaunt1969, is the ground post the one labeled "NEG"?

 

[sparky1]

sparky1, that diagram would be great

send me your address and what your vehicle is.