help guys im melting wires

[whynot225]

hey guys i realy need help . i just put a slant six in my 72 dart . i dont know whats happening the field wire on my alternator is melting its the one that splits from the bulk head and goes to the ignition balast and the alternator ....im super lost ...my first thot is i didnt hook up all the grounds because i only have the battery to the p/s bracket .. i would imagine the would be one to the body ..but i really have no clue ..but i guess it may be a bad alternator .do any one no were all the grounds go .or have you had the same problem . the pics would realy help :-k ops:

 

[67Dart273]

First thing to do is take a multimeter / continuity checker and check both the field terminals of the alternator to ground. Do this with both field wires pulled off the alternator. You should have infinity, that is no continuity

Sometimes one of the brush holders breaks, and becomes grounded. Rare, but the rotor windings themselves can become grounded.

 

[BillGrissom]

Does your alternator look like the one 67Dart273 posted? Both brushes are "isolated". In earlier alternators (most round-backs), one brush was grounded. Some people do that to later alternators so they can use the original 1-wire "high-side switch" Vreg. If your alternator has a grounded brush and you connect the 12 V ign wire to that, it will melt the wire. With ignition off, measure the resistance from that wire to ground. Should be >5 ohm if going thru the field and not shorted to ground.

 

[whynot225]

yes . looks just like that . i tested that wire with the ingnition off and its way higher then five ..wtf

 

[whynot225]

i checked my + off the battery to see if i grounded one but i dont see any .

 

[67Dart273]

yes . looks just like that . i tested that wire with the ingnition off and its way higher then five ..wtf

PLEASE READ what I asked you to DO

I did NOT say anything about the wire.

REMOVE BOTH WIRES from the alternator. TEST at the ALTERNATOR

Check continuity as in 'ohms' with your meter

With probes on the two alternator FIELD terminals, you should read a low resistance that is should show continuity

With one probe on GROUND, test each alternator field terminal. NEITHER should show continuity to ground.

 

[4spdragtop]

Do what 67dart273 says,(no offense Bill), he has helped me and dad a few times. Once over the phone with the exact same problem you were having...we melted the fusible link in dads 67 cuda 273. Del had it figgered out in 2 minutes over the phone. It was a bad alternator.
Im lost with the electrical, and what Bill says could very well be right, I just know 67dart273 has helped me...good luck!

 

[whynot225]

ok i just did that its saying -1 ????. thanks guys for the help

 

[67Dart273]

You just did what?

Where did you have your meter set?

If you can post a photo of your meter, or at least the brand and model that would help

Do you have an understanding of resistance readings? Different meters differ on what they display for an "open" or "infinity."

What does the meter say when the probes are hooked to nothing?

And, LOL keep your fingers off the probes when taking resistance measurements

 

[BillGrissom]

Just to clarify, I added things to try in addition to what 67Dart273 suggested. The melted wires could be from many different things. The O.P. hasn't posted pictures or described what he has tried clearly, so nobody can provide much help. When you call for help, be ready to help yourself.