24V BJ42 electrical issue (1 Viewer)

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When they changed the batteries? Do they do both or just one?

From what I understand, when you have 2 batteries running together, its very important to treat the two equally. IE: when you change one battery, you have to change them both, otherwise one battery will take out the other. You can't have one old battery and one new one. Its best if they are both matching brands and models as well.

Its also importat to draw off each battery equally.
If one battery has a greater constant draw than the other, then it could kill one.
Which means both will have to be replaced.

Others smater than myself will probably chime in.

Cheers,
Nick
 
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From briefly reading your other thread...you have some 12V draws being tapped off of your low side battery...this is a BIG no-no! Get yourself a Solar Converter or a 24-12V step down voltage converter and draw all of your 12V need off of there, make sure both batteries are well charged, and your problems will go away. While you're at it, take a voltage reading while your truck is running and the voltage regulator has kicked in and make sure that your alternator is putting out the right voltage to charge your battery bank.

If you do a search on 12V installations (CD player, CB, alarms, etc.) or Solar Converter, lots of informative threads will pop up for you to read. Good luck.
 
Both batteries are new, and the same, here is the specs

http://www.pol-r.com/pdf/automotive/p78dt.pdf

I do have a 24V to 12V converter for the indoor accessories, such has cig lighter, radio, and such.

I'll look into putting my viair compressor on it, but my converter is only 20 Amps and at max load the compressor will draw 30 amp i beleive. http://www.viaircorp.com/400c.html Yep 29 amps.

I will also put the fake led on that system, that should be easy.

But i think 12V head lights were originally connected to one battery, maybe some one else with a 24V truck can confirm, has i've yet not find wiring schem.
Again i could always put that wire on the 24V-12V transfo, but how much amp the head lights draw? I'm going to need one good transfo...

If toyota originaly installed the head light on one battery, i guess its ok?

When my engine is running the voltage is 27 to 27.5, so i guess my alternator is fine?
 
I just looked up 24V-12V convertor, seems like 40 amp does exists, i need to be sure how much the head lights use. They don't seem to be cheap tho.
 
eleblanc said:
I just looked up 24V-12V conertor, seems like 40 amp does exists, i need to be sure how much the head lights use. They don't seem to be cheap tho.

Do NOT run your headlights from a converter. Either ensure the stock system has not been played with and is hooked up correctly, or turf it and wire in 24V headlights.

Information about the the stock 12V headlight system on the 24V Cdn spec BJ42 can be found here:

https://forum.ih8mud.com/showthread.php?t=68379

Sounds like someone did not understand the stock hookup, cut all the wires, and wired both headlights off one battery. Bad news. I bet if your pull back the harness wrap on the right side fender you will find all the cut wires that were to go to the headlights.

hth's

gb
 
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Greg_B said:
Sounds like someone did not understand the stock hookup, cut all the wires, and wired both headlights off one battery. Bad news. I bet if your pull back the harness wrap on the right side fender you will find all the cut wires that were to go to the headlights.

hth's

gb

You may be right, mostlikely right, if i unplug that wire that goes to the negative of one battery thus pulling 12V and "both" headlights goes down, would that indicate someone screwed up the wiring, or maybe it is normal that both goes down.

I'll go through the wiring diagram this evening to fully understand it.

Thanks this should well be my problem.

Also i see there is a section missing in the diagram, if you have it all could you pm me. Thanks
 
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Would switching to 24V head light be has easy has changing the dimmer relay and head lights? i guess not, and what would be the implication?
 
eleblanc said:
You may be right, mostlikely right, if i unplug that wire that goes to the negative of one battery thus pulling 12V and "both" headlights goes down, would that indicate someone screwed up the wiring, or maybe it is normal that both goes down.

I'll go through the wiring diagram this evening to fully understand it.

Thanks this should well be my problem.

Also i see there is a section missing in the diagram, if you have it all could you pm me. Thanks

I've added another diagram to the other thread. I recall finding out the Toyota wiring digram was not fully correct (forget where it was wrong now), as I had a stock 1984BJ42 with which I took apart and followed the wires (trying to troubleshoot my 1981 BJ42 headlight issues).

I know there is some discussion of wiring the headlights to 24V and turfing the evil 12V center tap system but do not recall if it was here, or on the RMLCA archives at Birfield.com. I've not done it.

hth's

gb
 
Well i quickly took a peak and someone wired the right headlight to the left headlight wires, thus using the left current for the right head light. Now i need to find the original right head light wires.

I just cannot beleive after that much time i will finally find the problem. well probably it was a good thing someone screwed it up like that, it saved the truck to be used for the last 8-9 years...
 
the 3 wires for the right hand headlight were cut, i have no clue why. After testing those i realise one wire going in the dimmer relay was cut also. See pictures.

Greg would you have the orientation of the wires with there color codes in the connector plug? i worried they were mixed up and maybe they are not at the correct place anymore.

My guess is that whoever did this was to fix a problem, so i guess once the wires are reconnected i may run into that problem. Finger crossed....
Photo_081706_001.jpg
 
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Well i've reconnected the cut wires, Both light works. but the right side seems low. Probably due because the right hand side battery is low on power. But i don't know if the right hand side head light draw from the battery on the same side.

Huge thanks
 
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Since i've fix this wiring issue i never had any batterie issue, but has stated in my previous post, the right head light doesn't seem to have the same intensity has the other one. Now since then, i had a my head light stay on even if the pull switch was closed, or pushed. None of the parking lights are open, only the two head light, keys are not in the ignition and switch for head light turn off!!!

I have a kill switch that cuts the current going from the negtive off the right batterie to the frame, thus removing ground. When i turn that kill switch off, the left light closes and the right stays on. So i open the hood and unpluged the wire that goes on the negative of the left batterie that use 12V from the right battery, finally shutting down the right head light. :rolleyes:

The first time that problem occured, i went and moved the dimmer relay boxe under the dash and after a few hit, close and open the head light switch and switching off my kill switch i got them to shut down.

Does that sound like a bad dimmer relay? If so where to get one?
 
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It is pretty rare, but a filament in the bulb can break and cross over the terminals inside the headlamp and keep it lit... even with the switch off. I had this happen once (H4 lamps) and installing a new bulb solved the problem.

If I recall things correctly, the grounds are switched in this system.

~John
 
It is pretty rare, but a filament in the bulb can break and cross over the terminals inside the headlamp and keep it lit... even with the switch off. I had this happen once (H4 lamps) and installing a new bulb solved the problem.

If I recall things correctly, the grounds are switched in this system.

~John

I have both light up when the switch is off? Would the issue you describe result in both light being on?

The issue happened again today, i went and unplug the dimmer relay and both light came off. I openned the relay, sprayed it with contact cleaner and reinstall it. I'll see what that do.
 
center tap is a good balanced system as long as one headlight is 12 volts as 0 volts to 12 volts and other headlight measures 12volts to 24 volts which is still only 12 volt potential difference. each headlight runs off seperate batteries don"t run with burn out headlight .
 
For the record, i eventually found out the issue with the light being less bright then the other side and sometime staying on. The 3 wires in the right side headlight were mixed up and causing this.
 

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