So I was setting the timing, and hit my wrench against the back of the alternator. There were a few sparks, but everything kept running. I noticed that the alternator sound changed a bit. A minute later, it shut off and now I have no power to anything that goes through the ignition system. I've traced the power to the ignition switch and tried replacing that, but still nothing. Some idiot seems to have removed or bypassed every fusible link, I can't find a single one.

My question is, I noticed that the battery is sitting at 13.07 volts. I believe I somehow caused an overcharging state when I shorted out the alternator. I'm having a hard time chasing down a schematic, does anyone know if this over-voltage could be tripping some sort of protection circuit somewhere?

Also, any pointers on where to look next after the ignition switch? I couldn't get power at the fuse box, so maybe there's a short or a relay blown between them?

If anyone knows where I can get a schematic, I would be eternally grateful.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

I have an 83 FSM,
If you can’t locate a wiring diagram, pm me your email address and I will scan and email the 83 diagrams to you.

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

Trace the + bat cable. It goes to the starter relay and the body power feed is taken from there. Follow that heavy wire and you should find the fusible link you fried.

_________________
Joshua

Thank you. I found a fuzzy diagram for a '71, if that doesn't work out I'll take you up on that.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

So I traced it to the starter relay - there are two heavy wires coming from there, one goes to the diagnostic port and the other goes straight to the firewall, no fusible link there. I probed the same wire under the dash and there's power at least to where it vanishes under the harness wrap. I get power at pins 1 & 3 of the ignition switch. I thought it wasn't making it out of the switch, so I replaced it, but still no power. Ran out of time after that, tonight I'll probe after the switch and try and figure out where it's going. I'm starting to wonder if I also fried a ground somewhere.

I also picked up a 30A breaker to put on the main line where the fusible link should be. I want to find whoever removed them all and slap his ears up onto the top of his head.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

I had a few minutes, so I went out and started probing. Everything looked fine, so I turned the key, and lo and behold it worked. What the hell? The battery voltage had dropped overnight, maybe there is some sort of overvoltage protection circuit.

Tonight I'm going to re-wire the charging circuit, been putting it off for a while... don't want to send any more wires to an early grave. Thanks for the help.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

You can buy fusable link wire at NAPA,
I believe the fuse wire is two sizes smaller than the circuit it protects, but double check that.
I am not an EE, but I believe in some circuits a fuse link is preferred to a standard fuse, certainly either is better than neither.

_________________
Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

Thanks - I might check that out if the 30A breaker blows. Everything I've added is separately fused, and mostly everything else seems to have a fuse in the main box, so the biggest thing I'm worried about is protecting the main harness from frying if something shorts, and I think 30A should do it. I could see a fusible link working better if the current spikes above 30A often, I'll try that if the breaker isn't slow enough. I don't think it should, since the heater is gone and I'm moving half of the remaining circuits to separate through relays, but we'll see. At this rate, I think I'm about two circuits away from the entire thing being brand new, lol.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

I just spent four hours trying voltage regulators, alternators, re-wiring everything... turns out that the problem was the voltage regulator plug. The harness held it at just the perfect angle where suddenly the sense wire would lose connection and overcharge.

Well, hopefully it won't have this problem again anytime soon, now that literally the entire system is new. (other than the alternator, which I found in the bed covered in leaves)

Thanks for the help.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.

Congrats! Enjoy the drive...

Lou

_________________
Home of Slant6-powered fun machines

For those out there pondering how to size a fusable link, the rule is four gauge sizes smaller than conductor being protected.

Example:

Protecting a 10 gauge conductor one would install a 14 gauge fusable link.

Protecting a 14 gauge conductor use an 18 gauge fusable link.


Fusable links are slower to open an over current circuit than a standard fuse. There are slow blow fuses available generally used to protect initial high amp draw devices such as motors where a current spike may last a few mile seconds than drop back to rated draw.

Circuit beakers are slow to react to over current before tripping, but not so slow as to cause a melt-down, and after cooling down, will reset automatically. The factory installs one of these 30A breakers on headlight circuit, and is mounted on headlight switch.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC