Okay, here's the information:

1980 Toyota HILUX 4WD 20R engine


I recently purchased this beauty for 500 bucks and noticed that the battery was operating the ignition system (removed the battery cables and engine shuts down). Obviously the alternator and/or regulator are bad. I went about hunting for the problem, but couldn't find the issue. I hastily changed out the alternator and regulator in a desperate attempt to fix the issue-NO LUCK.

Here's what I do know at this moment:


alternator works- puts out the proper voltage/amperage


regulator works- passes continuity/resistance tests
wiring is good as far as I know- traced the wiring and there is continuity


Battery is BAD-wont charge over 11.5V, but it still shouldn't matter. If the system was operating properly there should still be 14.5V going past the terminals with the engine running, and the engine should continue to run with the battery cables removed. Battery is strong enough to start the engine and run the car. I've even driven it around town. Voltage is 11.5 both static and while the engine is running. when I put a load on it (radio, lights, etc) it drops down to 11V.


GEN light is functioning but NOT LIT while the engine is running???????


I performed every test in the HAYNES manual and the tests say that the damn charging system should work. If it weren't for the battery terminal test I would say the battery is the issue, but the alternator should run the ignition system with the battery removed once it's started. WHAT THE HELL IS GONG ON HERE????

 

Your battery could be your problem..

Or my other thought it your alternator doesn't hook into your harness. Have you checked the connections on the alternator? Try running a 10 gauge wire from the + battery post straight to the post on the alternator

 

Tested the battery. It is bad, but it's good enough to start the car and run it. I've even taken it on 60 mile trips with the lights on and there were no issues. I also pulled the good battery from my Camaro and placed it in the truck...same issue.

First- I never thought about running a wire directly from the alternator to the battery. It's those ideas I was hoping for. I know it HAS to be a wiring issue, I just have no idea what wire/harness. Jumping from the alternator will confirm the issue, but will be unregulated for a short time...keep the ideas coming.

 

Before anyone asks, I did check the fuses and they all are good. A 1980 only has one small fuse box under the dash, and the relays are all placed in difficult to get to places behind the dash. Fortunately I removed the entire dash, but all of the subsystems work, so I'm guessing there are no relay issues.

 

The fat white wire on the back of the alternator that is held on by a nut is supposed to go straight to the battery. It's also what powers the harness. Just run another wire from the same spot to the battery and see what happens. It won't hurt anything! I ran it like that on my '80

 

make sure all your grounds are in decent shape as well. there are a few body to frame, and battery to body connections.