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Discussion Starter #1
I installed a new 100amp 1 wire alternator. I disconnected
the yellow wires from the selonoid, that went to the old alt and regulator. On the way home from work I turned on the headlights, the guage lights were dim and I started to smell
smoke. I turned of the headlights and the smell went away.
I have 14.3 volts with the car running, when i turn the lights on the voltage stays the same. The guage (charge) in the dash which shouldn't be doing anything goes hard to the left when the lights come on. Is the higher voltage overloang my electrical system, Did i screw up droping the yellow wire off.
Wiring is not my strong point, I need help!

Regards,
BillGear

302 Roller, 5 speed, FTI Custom cam, AFR heads, 17 TT2's, Holley 650dp,see it at http://www.289mustang.com
http://www.289mustang.com/images/vmfcar.jpg
 

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Good question. I've got a one-wire Powermaster Alternator that I'm gonna bolt to my fresh motor (should start it this weekend, I hope!). I was curious about the yellow wire as well. There's one that ties into the old regulator and one over by the starter relay. I taped both out of the way but I was wondering about them. Is your switch original? If so then you probably need a new one. I've smelt 'em burn before, its the coils in the old variable resistor, the dimmer. Was the switch hot to the touch? If you turn your dash lights off or down low then it shouldn't burn, if that's the problem.

Question: Just curious. What guage wire did you use to hook the Alt up? I was gonna use 10 guage wire. The Instructions that came with the Alt were not complete. I may give Powermaster a call.

Black primer 66 coupe, bench seat, 302, C-4, 3.55 TSD.
879 posts as "66 bench-coupe" on old VMF.
<P ID="edit"><FONT SIZE=-1>Edited by 66benchcoupe on 04/24/01 04:11 AM (server time).</FONT></P>
 

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Discussion Starter #4
Probably the switch, I didn't feel if it was hot. To worried about the car catching on fire. I drove the last mile home without lights. When you don't have any idea were the
burning smell is coming from it gives you a very woried feeling. I used 10 guage wire for the ALT.

Regards,
BillGear

302 Roller, 5 speed, FTI Custom cam, AFR heads, 17 TT2's, Holley 650dp,see it at http://www.289mustang.com
http://www.289mustang.com/images/vmfcar.jpg
 
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The VR should prevent the system from receiving too much Volts from the alternator, it's why it's there... Even if you change from 55A to 100A alternator, the voltage should be the same, the difference between the two is that you can draw more current from the 100A alt before the battery starts to supply the shortage you might have if demand exceeds max output of alt.

If the amp-meter in the dashboard goes to far left (discharge) it probably means you have a short-circuit. The short-circuit is drawing so much current through the wire that it'll heat up and start melting the insulator. That's probably the smell you noticed.

If you don't experience the same problems if the engine is not running, check that the wires are connected correctly.
 
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If the switch were at fault, it wouldn't matter if the engine's running or not. The only difference is that with a running engine the voltage is a little higher (usu 14.4 instead of 12 V). The resulting increase in current wouldn't be enough to suddenly overload the system.
 

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Discussion Starter #7
The thing is it woked fine with the old alt, the old one only put out about 13.5 volts. I hoping the extra
voltage(from new alt) was enough to push the "old" headlight switch off the deep end. If the higher voltage isn't my problem then I have something else wrong?

Regards,
BillGear

302 Roller, 5 speed, FTI Custom cam, AFR heads, 17 TT2's, Holley 650dp,see it at http://www.289mustang.com
http://www.289mustang.com/images/vmfcar.jpg
 

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Headlight switches can act a little funny. I've had switches go bad that only got hot and smoked when the dimmer was in a certain position while other positions would seem like nothing was wrong, engine running or not. When it goes bad, the switch doesn't necessarily behave consistently.

Black primer 66 coupe, bench seat, 302, C-4, 3.55 TSD.
879 posts as "66 bench-coupe" on old VMF.
 
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Ah, but now we're talking a different part of the head-light switch. You're referring to the dashboard-light dimmer, right?

If the dimmer switch gets hot at a certain position it probably means that it shorts the circuit. The switch is designed so that this doesn't happen, but who knows what might have worn in 35 years...
 
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