Any help appreciated, 318 Alternator (Blue wire glowing red)

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74_Dustr

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Hey hows it going. been having some issue with my duster.. I haven't worked on it in over a month but went out to fix the oil pump. and after i hooked up the battery turn the key on and the blue wire from the bulk connector all-the way to the alternator was melting and glowing red at the alternator.... (I know its a short issue) My questions is what may be causing this.. Is it a Bad Alternator? When i un hook the blue wire from the alternator) but the ground and the Green wire are still hooked up... Nothing happens no smoke nothing melting nothing glowing.. The second i hook it back up with the key on Its back.... (Car fired up and ran with out it hooked up also) Oil pressure was back and car sounded better... But this issue wasn't here before... Now i did hook up oil pressure gauge mechanical, along with battery voltage and coolant temp... witch shouldn't of conflicted with it.. since i unhooked it all when i saw it smoking.. and then tried again and it still did it even un hooked...

And Since my wires are melted well at least the blue one... I'm going need re wire it.. is their some sorta Bypass i can do to bypass the connectors? I dont have a radio at all or speaker but i would love to put some sound in the car. so id like to get bigger alternator at some point too
 
Dead shorts like that are usually related to the dash harness. Check the leads on the Alternator gauge for signs of shorting against the aluminum cluster housing. If you cooked the harness, let me know. I've got a good one here.
 
Ill check that out tomorrow is there anything else i should look out for?
i know my fuse box could use a new one.
The car was originally a slant 6 and had a v8 swap but who ever did it.. pretty much rigged it together. the motor mounts are welded to the slant 6 member (crappy welds at that) They didn't space it out or anything its metal to metal contact. .. The exhaust coming off the headers hit the steering arm. and the steering arm goes under the oil pan (witch they had modified and cut to clear the steering arm and made it into a rear sump pan.. (so the oil pump doesn't have a pickup screen instead its a rubber tube that goes to end of oil pan.)

My head lights have always flickered they will get dim then bright.. then dim and bright again only with high beams on... ( i changed voltage regulator and it stopped doing it all the time, only with the brights on.. so that could be an issue with all this too..

how much for the harness?
 
Hi,

My first thought is that one of the brush holders on the back of the alternator has cracked and failed shorting out the blue wire which is the 12 volt ignition circuit powering the alternator field. I would pull the alternator off and take a careful look at the brush holders. If you have a volt-ohmmeter you can check for continuity to ground. Neither field terminal should be grounded but instead are isolated from the alternator frame. The brush holders and new brushes are available and easily replaced.

As you already know you'll need to replace the burnt wiring.
 
^^^ If the OP just unhooked the blue wire at the back of the alternator and nowhere else, than that is a very good likelihood explained by Pete. Start by looking for a short there as described; such a short could be either of the brush holders or if could be in the field winding inside the alternator.

Also, some of the rebuilt regulatros come with a shorting strap to the case ground so they can be used for the older 1 filed wire system; check that connection point for the blue wire to make sure a shorting strap was not left in place, especially with the other crapy stuff done before!

OP, do you have voltmeter and know how to use it in the resistance measuring mode?

If you have melted insulation the blue wrie all the way to the bulkhead connector, there is reason to belive that it will also be melted back into the car's dash harness all the way up to the ignition switch. And it could have damaged the red power wire into the ignition switch. So, to be safe, you need to go in and unwrap the dash harness and inspect it all the way back to the ignition switch. Car fires are nasty things....
 
yea i know how check resistance. my old mustang caught fire due electrical.. definitely not fun
 
Make sure the insulators are where they belong under the wire terminals on the back of the alternator also.
It's real easy to miss how and where they go if they got moved damaged or melted. :-)
 

You have found the trouble. Pull the alternator off and check it out

The blue wire is switched 12V and is not fused. It feeds 12V directly to the field. The green wire controls "the amount of ground" so to speak from the regulator

If the blue wire is smoking, you have a short right there, either the brush holder or internally in the alternator rotor.

With both field wires off, neither brush connection should show continuity to ground.
 
67Dart273 said:
If the blue wire is smoking, you have a short right there, either the brush holder or internally in the alternator rotor.
Click to expand...

Is the little plasic connector insulator under the blue wire connection called the brush holder?

That was what I was trying to say if it is, sorry if that wasn't very clear.
 
Thanks for the help guys, I found the Problem.. It was All my fault.. when i hooked up the tachs to the alternator, i Took off the brushes to check them and make sure they were good, well I forgot the Nylon washer that goes in between their.Put one on and everything works properly, Luckily the wire never melted passed the engine bay.. so it didn't touch the dash. so that was simple fix. luckly ( i just went back over what i did and found the problem)



I Am wondering if I bypass the ammeter would be beneficial to my dim headlights..
 
Glad to hear you found the problem and that the wiring wasn't burnt too badly.

The biggest help for the headlights would be to use relays to control them and get all the highlight switch wiring and bulk head connector pins out of the high current circuits.

Try doing a search in this section on headlight relay modifications.
 
TrailBeast said:
Make sure the insulators are where they belong under the wire terminals on the back of the alternator also.
It's real easy to miss how and where they go if they got moved damaged or melted. :-)
Click to expand...

Ha :D

Glad it was an easy fix.
 
Well, if you never made a mistake it is only because you never tried anything. Glad that it did not go into the inside area.
 
nm9stheham said:
Well, if you never made a mistake it is only because you never tried anything. Glad that it did not go into the inside area.
Click to expand...


I look at it this way:

Try anything. If you screw it up, you can always pay someone to fix it if it's out of your capabilities.


If you don't screw it up, you just saved a bunch of money from not having to pay someone to fix it for you.


Or learn from your mistake and fix it yourself properly the second time....


Either way, you learn something by trying.


You don't learn anything or get better mechanical skills by paying someone else to do it from the get-go....
 
krazykuda said:
I look at it this way:

Try anything. If you screw it up, you can always pay someone to fix it if it's out of your capabilities.


If you don't screw it up, you just saved a bunch of money from not having to pay someone to fix it for you.


Or learn from your mistake and fix it yourself properly the second time....


Either way, you learn something by trying.


You don't learn anything or get better mechanical skills by paying someone else to do it from the get-go....
Click to expand...

Amen, and if you do screw it up it'll very likely be less screwed up than a lot of shops would screw it up. :D
 
And I have to say that it is talent to get a 16 gage wire to actually glow red and not just go 'poof'!
 
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