ifawkingh8electrical (1 Viewer)

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nuclearlemon

not an addict
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going back to my 76 pig help thread...here's the story; i hope it makes sense to you cause it makes non to me

right before moab, had issues where when truck was at operating temps, ammeter would peg hot under throttle. let up on the gas or hit the turn signals and it would go to just above 0 like normal. it would not do it on the way to work when the engine wasn't warm enough to reach operating temps. figured voltage regulator and swapped in a new one.:bang:

everything was fine for a couple months both in daily driving and going to and from cruise moab. got back from moab and parked the rig for a couple months. went to drive it to work one day and the battery was dead, so threw in an extra battery that was charged. fine going to work (when engine was cold), but about 1/3 of the way home, ammeter pegs again just like before. buy another voltage regular and next day, same thing. park it for a couple days til the ex could come trouble shoot and he finds a dead cell in the battery. replace with another battery and all is fine for a couple months.:bang:

coming home from a friends, i blow a tire badly. swap on spare and try to drive to work, but three no tread bias plys and one brand new bias ply convinced me that i should park it until my new tire comes in. tire is backordered for two months. in the meantime i clean some connections to the tailgate wiring.

tire comes in, but now battery is dead. disconnect it and trickle charge it for a few days and go to hook up battery. get a spark when i hook up negative, but figure it's radio or something. fire up cruiser ammeter pegs hot hard so i rev it once quickly and determine it's not going to go to drop down to normal voltage and shut it off. go over to battery and alternator wire off battery is smoking. quickly cut wire and disconnect everything.:bang:

figuring i had to have screwed something up when i was dicking with the tailgate, i disconnect wires at junction block and start hitting things with the test light. not the problem:bang:

next, i think wires might be pinched in the tailgate so i find power wires where they run by passenger door and cut them. not the problem.:bang:


put test light on positive batt post and touch alternator batt post and it lights up. with test light on battery positive touch case and it lights up. thinking maybe alternator is internally grounding, i buy new alternator. same freaking problem. :bang:

my test light shows flow of current (lights green one way, red the other way), so i check battery. clip on negative, probe on positive lights green. check the battery in my 80 and it's opposite. check battery in the 45 and it's opposite, check battery in green pig and it's opposite, so i think the battery is jacked. take the brand spanking new optima out of the 45 and put it in, but that still isn't it :bang:

disconnect voltage regulator, unhook all wires from alternator and touch power wires to battery. no spark, so i hook them up. go to hook up battery wire on alternator and bad spark. they spark like the batt post on the new alt is grounded.:mad:

literally the only time i get no sparking is when the batt wire is not hooked up to the alt so i'm thinking it has to be the alt!:bang:

can anyone who doesn't suck at electrical confirm? or, can someone with a good running 76 try disconnecting the bat wire on the alt and hooking it back up and seeing if they get bad spark?
 
Ooooh, kinda confusing ands starting to go in circles.

Sounds like a dead short in the system somewhere, try the unpluggin fuses......................


Woooow, as I started writing this I understand you have a ground between battery and alternator were there is no fuse? surprised the fusible link did not cook first.

Mac Tools sells these fairly expensive breakers you can put in the system to prevent burning your rig down while testing, handly little fellers.

Im thunking you got a hot wire worn through somewere or crossed to a ground?

Dunno without being thier, to bad I sometimes enjoy chasing these gremlins.

Goodluck

Rob
 
yeah, someone previous to me eliminated the fusible link. i added one of the 80series fusible links that i had in my toolbox.

now I CAN JUMP UP AND DOWN IN JOY!!!

third alternator is a charm. for info, the two shorted alternators were autolites from checker.
 
hmm....maybe will explaing my 55 alternator charging issue...
 

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