Darn electrical gremlins

[CManT1914]

I burned up another alternator cable today. It melted the metal bolt coming out of the alternator, and the metal terminal completely off. What in the world? It's a brand new voltage regulator. Would a bad ground cause this problem? Or is it more likely the alternator itself?

 

[SeventyMach1]

Did you JUST NOW get a new/upgraded VR? If not ..... what have you added or done since then (that could possibly cause this)?

I'd take it & have it tested. ( it would be cool to watch their machine wires melt ... ) J/K. Yeah, a bad ground could cause it to do that ..... or the "grounding" of something thats not supposed to be.

 

[HISSIN50]

Chris, did it melt to the bottom bolt? Which wires melted? Is the main (amperage carrying) cable ok (that goes to the distribution block)?

Does it happen when the alt is hot, cold or both?

Justin, I think he replaced the VR and one connector a couple weeks ago (seems about right, time-wise).

Good luck Chris!

 

[CManT1914]

Justin, it all started happening after my heads/cam swap. I think I must have gotten a ground not attached good.

JT, the cable that goes to the fuse box, that melted. The post that it attaches to, that melted also. I really don't know when it happens, I just know all of the sudden I had no voltage, and I popped the hood when I got to my dad's shop, and it was melted again.

 

[HISSIN50]

Chit man, melting a 6 AWG cable is not good. It should not have done that without melting the fusible links either.

Were it me, till I sorted it out (wiring vs alt), I would run a new cable with 4 AWG and use a 125 amp fuse.

Is the stock charge cable shorting anywhere that you can tell (as it runs under the coil, etc)?

I am too tired to think straight. Good luck man!

 

[urban96]

is your alt hitting the valve covers? could be grounding out there somehow

 

[CManT1914]

Chit man, melting a 6 AWG cable is not good. It should not have done that without melting the fusible links either.

Were it me, till I sorted it out (wiring vs alt), I would run a new cable with 4 AWG and use a 125 amp fuse.

Is the stock charge cable shorting anywhere that you can tell (as it runs under the coil, etc)?

I am too tired to think straight. Good luck man!

That's what boggles my mind JT, is the fusible links are in perfect condition (at least they were last time, I haven't looked at them this time yet).

I would have ordered that cable and those terminals and all that from that website you emailed me, but everytime I've checked, they're out of stock on half the stuff.

The stock cable looks good all the way down, not even melted in the least bit (I'll take a closer look tomorrow).

I talked to one of the other mechanics at work today, and told him the situation. He said it sounds like a loose or bad ground somewhere. I know that at least one of my grounds was not hooked up after I did my heads/cam, I saw it a few days later, and I hooked it back up. I might have missed another one somewhere in the process.

is your alt hitting the valve covers? could be grounding out there somehow

I am pretty sure they aren't hitting, but I'll check for sure tomorrow.

 

[HISSIN50]

In that case, run an extra ground (I just picked up a cable yesterday so I can run an auxillary ground - just in case).

You really could make a new alternator cable from parts store stuff too. A bulk/generic cable from the battery cable section, and either add a fusible link to it, or put an inline fuse. You would have to solder a couple connections, but then you know you have a fresh cable for now (and it should be for a cost of well under 20 bucks).

I am still thinking on what else it could be. Intermittant and goofy stuff like that is a pain to track down.

Good luck Chris and have a nice Turkey day!

 

[CManT1914]

JT, how would I wire an auxillary ground? Where would I splice the new cable to? I went ahead and ordered that cable (5ft) and the rest of the stuff. Only bummer is, the cable is out of stock until 12/07! :damnit:

But if I could wire an auxillary ground, then that should take care of the problem, especially if I go over all my factory grounds too huh? I have tomorrow off, thinking about working on it then, so let me know (I know you will, you always come through for me when I need it)! Thanks JT!

 

[HISSIN50]

I have not finally decided upon where to run the ground myself - I need to get under the car and look. I remember that going from the motor-side of the motor-mount to the frame (the anti-sway bar bushing mount is one spot I saw) on the pass side would work. That is not near ideal, but it was all I remember (I was not under and lookin for a spot, so I am going with crude recollections). I know some of the guys in here who do the wiring upgrades will have cool spots picked out (I should check Shane's page out since I know he upgraded all that stuff, esp for his big alt. Mike and others would likely have similar info).
One would want a new ground from a clean spot on the motor to the frame, and upgrading the ground (or augmenting it) from the battery is also good.

You could use a parts store battery cable (one with two eyelets). That cable generally has really thick individual cables (as opposed to the cable from PE, which is very fine and easy to work with). I have made my own connections with both though.

Sorry to not have better info. If I can, I will take a look tomorrow. I know you can find something good yourself (probably better than I can).

 

[CManT1914]

Thanks JT, I'll probably start a new thread about running an auxillary ground.

 

[mo_dingo]

Just some food for thought. Have you removed that connection recently? Is it possible that the connection got loose? That is the #1 reason wires melt. A loose connection increases the amps dramatically and cause this.

Secondly, did you install the voltage regulator correctly. Possibly backwards? The alternator puts out 14V AC and the regulator is a diode pack, which only allows current to flow in 1 direction for one, and also converts the 14V AC to 14V DC.

So if the diode pack was installed backwards, the battery would power the diode pack and allow current to flow to the alternator and cook it.

So you might want to check out the regulator first. Then, if you have ruled out any loose or bad connections, you should look to your alternator.
Scott