qletsinger Posted April 10, 2013 Report Share Posted April 10, 2013 I have an 84 720 and i replaced the alternator a while ago and it has been working fine. Just recently i have had some problems with stuff inside the cab. Whenever i step on the brake my stereo will shut off. I have a volt gauge in the dash and that will go all the way down when i turn the car off. It always used to stay around 12v when the car was off. And my dome light wont turn on when i open the door if the car is off but it will when it is on. Could this possibly be my battery? Or a short somewhere? Does anyone have a wiring diagram? Quote Link to comment
datsunaholic Posted April 10, 2013 Report Share Posted April 10, 2013 You have a broken ground somewhere. Quote Link to comment
datzenmike Posted April 10, 2013 Report Share Posted April 10, 2013 If your horn, heater fan, stop lamps, turn signals, marker lamps or clock also don't work with the motor off then check the fusible link. They are located very near the positive battery ternminal, are about 4" long and have connectors on the ends so they can be removed. It will be the BLACK one. (there are two Green ones too) It may be loose or disconnected but likely melted looking or the wire inside burned and crumbly. If this fusible link is broken there is no battery power to the fuse box for the items I listed above however the alternator output also feeds back through this wire to charge up the battery so there IS power when the motor is running. I expect your battery to be slowly going dead. Quote Link to comment
qletsinger Posted April 11, 2013 Author Report Share Posted April 11, 2013 I wired up a new fusible link and the problem was solved! What would make a fusible link blow? Quote Link to comment
datzenmike Posted April 11, 2013 Report Share Posted April 11, 2013 Well it's how charge gets to the battery from the alternator. If the battery was low and the alternator charging at full tilt it might overcharge and blow out the fuse. Black is color code for 80 amps. Stock alt. output is only 60. Is it possible the output cable on the alt. touched a geound while swapping the alt. out? This would have been a dead short to ground and would have zapped hundreds of amps from the battery through it. Quote Link to comment
qletsinger Posted April 11, 2013 Author Report Share Posted April 11, 2013 Ok i see, well thanks a bunch for your help! Quote Link to comment
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