Electrical prob, need solution

'86 Toyota PU. I need help troubleshooting this one. My charge light came followed by the loss of my turn signals and fuel gauge. I tested the alternator and it failed. So, I replaced it and had a load test done on the battery to be sure it wasn't too far gone. It passed the load test. So, after installation of the new alternator I started it, but still have the charge light on and same issue with the fuel gauge and turn signals. The battery simply isn't getting charged. I checked the fuses and relays and everything seems OK. The emergency flashers work. I pulled the new alternator out and had it tested, it passed. I checked the wiring harness and didn't find any suspicious problems. Any suggestions where to go from here would be appreciated!

[QUOTE=Goober] The battery simply isn't getting charged. QUOTE]

How do you know that the battery is not being charged? If it really isn't, could be the voltage regulator.
As far as the fuel guage and turn signals, you do know that the fuel guage is the only guage that does not go to zero when the truck is off. All other guages (battery, oil, water) come up when key is on.
Turn signals sounds like a flasher relay. If voltage regulator died, it could have smoked something else with a voltage spike.

Thanks for the feedback. When the Charge light went off, the fuel gauge just dropped. I discovered the turn signals were out about a block after that when I was turning. I understand the fuel gauge doesn't go to zero when shut off, that's why this is an unusual one for me to troubleshoot. And, the emergency flashers still work. So, doesn't that indicate its not the relay? I was told the regulator was internal in the alternator by a mechanic, not sure what to do with that one. I had the alternator tested. If you know for sure that its not internal, please tell me where it is in the engine box and I'll play with that. I think the voltage spike is a good possibility and that might be what fried the signals and fuel gauge. Guess I'll be running backwards through wires from the terminal and fuse/relay box.

I check my book. The regulator is internal. Did you check the fuse under the hood by the battery? I believe there is a AM1, AM2, engine and charge fuse there.

I did check the fuses, including all those mentioned. What I do not know is if the relays marked CMH/Fuel Heater or Head, if blown, would contribute to my problems. Any ideas on those? I don't have a manual on this since this is the first real problem I've had with it in it's lifetime - all 178K! I'll be getting one after this.

goober, I have identical problem. did you find an answer?

this also just occured in my 1980....anyinfo

Y'all have a power feed to the interior making a bad connection. This could be as simple as the ignition switch or a faulty fusebox. Start tracing the power feeds but don't destroy your trucks. I'd suggest you use the alternator light as the refence point.
The way the light works is like this, one of the small wires from the battery feeds the interior and goes to the ignition switch. When you turn the switch to on it sends a + signal to a light bulb in your dash. The other side of the bulb is connected to a wire going to the alternators L terminal on the regulator. Once the alternator begins to charge it sends + back to the bulb, two + will turn the bulb off since it no longer has a ground.
Therefore once you find the missing link to the initial + and get that light to operate properly your problems will be cured.
:thumbup:
Get a wiring manual!

the fuel guage is the only guage that does not go to zero when the truck is off.

Mine does. And as for your turn signals, try replacing all 4 blinker bulbs, one might be blown. When my front driver bulb went out my turn signals would flash really fast when I turned them on, so thats a possibility.

one of the small wires from the battery feeds the interior and goes to the ignition switch. When you turn the switch to on it sends a + signal to a light bulb in your dash.

If you're talking about the ACC wire, its Blue/Red in the steering column.

I got mine figured out........I replaced all my fuses (they were really old), and the turn signal relay had fallen off.

I just started having that charging light problem, but thats because I managed to pack a 1000w amp under my driver seat and a 8in tube behind the seat :whatwhat: