PLEASE HELP.. electrical problems

[rougetoaster45]

Okay this is kind of a long story but please help...

About 2 weeks ago something started killing my battery through extensive test me and my dad found it was the alternator with a bad diode. I changed the alternator and everything was fine for about a day or so.

Now if I get in my car and go for a drive and come home and park it takes about an hour for my battery light to come on. When it is on that is with the truck off and key out so I started testing things..

1. I thought it may be ignition switch/lock switch so I changed both to still have the same problem.
2. I unplugged the new alternator while the light is on and nothing happens to the light...it is still on
3. I put a meter on the started solenoid. It read 12 volts on one side and .1 volts on the other...


While the truck is sitting with everything plugged up after the light turns on I happened to be under the hood and the alternator was very hot to the touch...and that's with the truck off key out. And I'v unplugged the battery posts and let it cool down and hooked them back up and it starts to get hot again after an hour or so


II just don't know what else to check for....i bought the battery a week ago and the alternator 3 days ago and I'm really at a loss so any input will help.

Btw it's an 88 Ford Bronco II xlt

 

[ab_slack]

Diode bad again in alternator?

There is the field coil that gets power when ignition is turned on. I don't know how much heat that can make nor how fast it can drain battery.

Energy does seem to be going into the alternator.

 

[rougetoaster45]

Something new to add...While battery light is on truck off key out if I unplug the alternator it stays on if I plug it back in it goes off..I'v only done this once so I don't know if it's a definite thing...i will be trying this through out the day...me and my dad were thinking that if the alternator is unplugged while the bat light is on how can it still be the alternator?

 

[ab_slack]

I don't know what the battery light indicates without looking it up. One of two things. Low battery voltage or it is indicating the battery is getting discharged which is not the usual state for the battery while the engine is running.

Now something is puzzling me. If you have the key off and removed, why are you getting a battery light? Far as I know with ignition off there shouldn't be any power to any of the dash indicators.

You aren't seeing other things working with ignition off key out like radio, fan for the heat/ac, etc? Other than the interior light, door chime, headlights (if on) and brake lights, there isn't much that should operate.

So goes back to what I said before, power getting to the field coil that shouldn't be would be consistent with electrical power getting to the light that shouldn't be.

I don't know if that is thru alternator or if something else is at work.

If this additional symptom if repeatable that it stops when alternator disconnected and doesn't re-appear after reconnection there could be some relay latching the power on and when alternator removed power is lost to the relay, relay goes off so when re-connecting the power is no longer there. A sort of like both things need to be present to keep power going and removing either causes it to go off.

Lots of electrical diagrams here http://www.therangerstation.com/tech_library/EDiagrams/index.htm

But there doesn't seem to be one related to where I would think your problem is, at least not for your model year, just earlier years and even then just one of the two pages.

This may be some help too http://www.therangerstation.com/tech_library/chargingsystem.shtml

 

[rougetoaster45]

To give an update. I went to my dad's house after work. After I parked the truck and it sat for a few min the battery light came back on. Ended up finding a wire that was grounding on my amp in the back so I pulled the whole radio out of the dash and disconnected it...still draining the battery. Truck off and key out

We decided then to start pulling interior fuses to see which on would turn the battery light off..we ran across fuse #18 which is carburetor circuts; warning indicators; shift indicator; low fuel warning; seat belt warning and deisel indicators and tachometer.. the only three things my truck has that I know of are the warning indicators and seat belt warning and tachometer

We pulled the fuse and checked the volts to it and it read anywhere from 5 volts to 6 volts. On power side with switch off My question is is this circut suppose to be hot all the time or only with the key turned over...why is it only getting 5 to 6 volts

With that fused pulled I headed home. Hoping that was it. I got home around 7 o'clock and read the battery w/ my meter @ 12.70.....at 9:00 tonight it read 11.92. I also noticed when I came outside To check the voltage when I put the testers on the battery I heard a click then sounded like something kicked on and then another click and it was off not sure where it came from or what it was.

 

[JerryC]

Just thinking out loud...
stuff powered when the key is out of the ignition:
Lights; headlights, tail, brake, interior.
Alarm system if you have it.
Factory radio with clock
Anything aftermarket, stereo, amps, etc...

Do you have aftermarket high intensity bulbs in your headlights? I hear that they can cause issues with the headlight switch.
How do your lights (heads, tails, brakes, dome) look? If your losing power to ground they might be a little dim.

Anyway, try pulling the headlight switch.
Another guess would be a short in the steering column.

 

[JerryC]

To check the voltage when I put the testers on the battery I heard a click then sounded like something kicked on and then another click and it was off not sure where it came from or what it was.

I don't know if the relays on the BII make noise, but that does sound like a could be a relay. You could pull those one at a time and see.

 

[rougetoaster45]

I don't have any aftermarket headlights my interior light fuse is pulled b/c the back gate doesn't close far enough headlights are not dim when the battery light comes on. (Aka the drain starts) I guess my next move is to check relays after I get off.