Could it be my charge lamp relay? Checked all of the connections for alternator, grounds, wiring to battery. I am kinda stumped, changed out all fuses to proper amperage, checked all wiring connections in the cab????

 

Did you check the voltage at the alternator?

 

does your ebrake light stay on too?

 

No I didn't, where do I test it? At the connections?
I replace to alternator with OEM part if that makes a difference?
(sorry first timer)

Ebrake does not stay on just the charge light

 

you can test charge at the battery terminals while the engine is running. should be charging above 12.9v
what type of yota do you have?

 

Tuesday(truck)is 86-96 4Runner under a 1980 4wheel drive truck body. She is a Frankenyota. The state of CA calls her special construction which is cool because we can do what ever we want as long as she stays street legal. Toyota calls her a Frankenstein truck but wants pics when she is fixed and legal.

 

well, if everything is working properly, it might be the charge-light wire shorting to ground somewhere.

 

Electrical is my recent bane...yet more wiring I need to track down. I will take the ohm meter to it today and find out if everything is working right

 

ignore the blue and green, those were my measurements from my problem.

the charge light wire (solid yellow) is on when there is no current in the alternator. when it's charging, the yellow wire gets 12v, so when the light has 12v on one side (ignition) and 12v on the other (charging alternator), there is no voltage through the light. if the yellow wire is touching ground, it will stay on as long as it has 12v from ignition.

 

I have seen the light flicker when I first got the truck so it makes total sense, that a loose wire might be causing the problem. I tested the DC at battery post while running and it was 13.86. I will track the wiring back and find out where the contact is happening. I just wanted to make sure there wasn't something I was overlooking. That might be where my short is too, I have to disconnect the battery when I park it for a while.


Thank you for the schematic and the great explanation

 

Got it fixed finally today, I don't know why the light EVER flickered off. I unraveled the tape off of the wires coming from alternator going to cab, unconnected wires just taped up in the bundle and not connected together. Who ever wired this truck was trying to start a fire. I don't know how the truck made it home when I bought it without catching on fire or the battery dying....crazy