Fried RamJets Aternator wire harness.

Bullshark

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St. Charles, Missouri
On the way home from Benefit Car show for fallen police officer Saturday, RamJet's charging system shot craps. The amp meter started reading negative amps and burnt smell came from engine compartment. I quickly pulled over at the nearest bar to assess the situation. No impending fire danger so we went in for a few beers :mobeer: before tackling our alternatives. My brain works better when not stressed.:D
Turns out the brown-white striped resistor wire from terminal #1 on the alternator to the firewall connector via ignition switch, melted and fused in the front engine harness. Multiple wire insulators melted.

Wondering what the root cause might have been???

Couple of weeks earlier my old battery went totally dead......my fault, left the ignition key on. :bonkers: Not even a starter solenoid click. I jumped the car, and limped home hoping it would charge. Turns out it was toast so bought a new battery. Things seemed to work fine after that....till Saturday.

1) Did I over heat the brown/ white wire when trying to charge the old battery, melting and causing a pending short. Didn't think GM would design a system that would allow that???

2) More likely did the regulator shoot craps shorting terminal #1 to ground?
Have to check that out next spring. Going to Florida for winter!:bounce:

So, how best to fix?? Probably need a new alternator, but which one to get??
If I stick with 3-wire, I plan to fix harness and run a new brown white copper wire with a 10 ohm 6 watt, power resistor in series to power field winding. Has anyone done this?

Appreciate any additional thoughts

Alternator schematic for reference.
175817e22cdafb0.jpg
 
I have a 17SI alt. on my car, 108 amp, same mounting, slightly larger diameter changed pulley to serp drive....I rewired my car so many years ago, I forget all that factory color codes/wiring, long ago I changed over to a voltmeter, along with the custom gauge pack....all my underhood wiring except front headlights/etc was replaced when I did the first install of FI 20 years ago.....

Sorry I can't really help, as to your specifics......

:goodnight:
 
On the way home from Benefit Car show for fallen police officer Saturday, RamJet's charging system shot craps. The amp meter started reading negative amps and burnt smell came from engine compartment. I quickly pulled over at the nearest bar to assess the situation. No impending fire danger so we went in for a few beers :mobeer: before tackling our alternatives. My brain works better when not stressed.:D
Turns out the brown-white striped resistor wire from terminal #1 on the alternator to the firewall connector via ignition switch, melted and fused in the front engine harness. Multiple wire insulators melted.

Wondering what the root cause might have been???

Couple of weeks earlier my old battery went totally dead......my fault, left the ignition key on. :bonkers: Not even a starter solenoid click. I jumped the car, and limped home hoping it would charge. Turns out it was toast so bought a new battery. Things seemed to work fine after that....till Saturday.

1) Did I over heat the brown/ white wire when trying to charge the old battery, melting and causing a pending short. Didn't think GM would design a system that would allow that???

2) More likely did the regulator shoot craps shorting terminal #1 to ground?
Have to check that out next spring. Going to Florida for winter!:bounce:

So, how best to fix?? Probably need a new alternator, but which one to get??
If I stick with 3-wire, I plan to fix harness and run a new brown white copper wire with a 10 ohm 6 watt, power resistor in series to power field winding. Has anyone done this?

Appreciate any additional thoughts

Alternator schematic for reference.
175817e22cdafb0.jpg

Is this an old/recycled schematic? (Otherwise just curious why D2 is shorted out.)
 
Old recycled schematic I found on internet. I just thought it was there to dissipate field winding energy and protect TR1 when it shut off. I looks penciled in so not even sure it's part of the hybrid regulator. If that diode was shorted out though, that would surely fry my resistor wire alright.
 
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Looks to me whoever did the black overlay was attempting to remove the diode from the schematic, and for the life of me I can't see why it would be there in the first place......
 
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