Looking for Stone or any electrical wizzards out there

[coldtaco]

Hi Stone. What I want to do is mount a pair of 24V 130w aux lights. I want to make it so that I can turn them on with the high beams or on/off independently. So I will be using a on/off/on light switch. The problem is how to get it hooked up with the high beams? Can't figure out by the scematic how the high beams go from 24V to 12V. I am assuming of course that at the light switch it is 24V. Do you have any ideas on this? I had to get the bulbs from Germany. If all else fails, I will just have to run the lights the old fashion way and have them be on/off only. Thanks. Stephan

 

[Stone]

Hi Stephan:

I'm just finishing up a movie with the wife right now...I'll have a schematic ready for you late tonight or early tomorrow. I think the lights in the 70 series are ground switched...and this is the way you should also have your aux lights switched. I have the same lights (IPF 900, 24v 130W H3 bulbs)...and I have them ground switched through a 24v relay.

It should be easy enough to figure out how to wire it the way you want...I just have to consult the FSM. Basically the relay coil will see ground when either your high beams are on or when you flip the aux light switch, causing the relay to flip the load switch and providing current to your aux lights and turning them on. The only thing I can think of is that here in BC, you are required by law to have your off-road lights covered at all times except when you are off road. I don't know what the regs are in Alaska, but if you have them covered and forget about them while you have the high beams on (and therefore having the aux lights on also if you wire them that way), then it would be easy enough to melt the plastic covers if you have them on long enough...and I know that the 130W per bulb does generate heat. I guess it's no big deal to replace plastic covers.

Cheers.

 

[Greg_B]

Can't figure out by the scematic how the high beams go from 24V to 12V. I am assuming of course that at the light switch it is 24V. Thanks. Stephan

Hi Stephan

Your BJ70 is 24V...correct? I know Toyota used the center tap system for the Cdn spec 1986/7 BJ70, and the HJ60. The following is how the center tap works with the Cdn spec BJ42's. I am assuming that Toyota would not have changed the basic principle for the 70/60 Cdn spec 24V trucks.

Toyota used a funky center tap system to run the headlights 12V on a 24V truck. This center tap (from the negative pole of the highside battery) runs to a 12V dimmer switch and powers the swtich. The dimmer switch also has a 24V wire coming into it. The dimmer switch splits the 12V and 24V's to the headlight wires. One headlight will have 0V neutral, and 12V's supplied to the lowbeam and highbeam pins when the lights are one, as selected by the high/low indicator. The other headlight will have 12V neutral, AND 12V to the lowbeam pin when the headlights are off, and 24V's supplied to the low and high beam pins when the lights are on, as selected by the high/low indicator. 12V neutral minus 24V selected pin leaves 12V for the headlight. With this system one headlight uses power from the highside battery, and the oother headlight uses 12V from the lowside battery, balancing the battery load.

Some people simply get rid of the Toyota center tap system, and wire the lights 24V, moving to the KISS principle.

This does not answer your question, however may assist those who can.

hth's

gb

 

[Stone]

Hi Stephan:

Well, it's bloody cold outside (although probably downright summery for you Northern boys), and I was having a heck of a time holding the flashlight and trying to put my multimeter probes in the right spots...so I'm going to check it tomorrow.

From what I can gather in the FSM, the headlight combination switch provides a connection between pin 13 and pin 5 in the wiring harness when the high beams are on. The only question is whether pin 13 is a (+) voltage lead or a ground lead...that would determine what the headlight high beam relay needs to see to activate. I'll check for you tomorrow when there's daylight and it's a little bit warmer.

In the meantime...this is how I've wired up my aux lights:

 

[Greg_B]

Stone, the FSM will not show the center tap system. I will send you a picture of the Service Addition that Mike Graham sent me a few years back. This addition is still not completely correct, (in relatin to the BJ42 center tap system) so do not trust it. I was into my BJ42 headlight system on the 1981 cleaning up a PO's mess. I took apart the 1984's wiring harness to the headlights and traced/figured out the stock system, then fixed the 1981's. I found the factory addition lacking.

hth's

gb

 

[Stone]

Greg:

I wasn't going to fool around with the center tap system. I was hoping to replicate what the switch does on the dashboard, as this would be a low amperage or ground switching type application. The harness under the steering column should be the same, it's just after the relay that things change with the 24v-12v lights, right? Anyway, I'm sure if I find the right wires that Stephan will check them before making the connection. Thanks.

 

[Greg_B]

Yes, perhaps. I followed the wires from the tap to the dimmer, and then the dimmer back to the engine bay and to both lights. I did not investigate between the switch on the column and the dimmer.

gb

 

[coldtaco]

Thanks guys. I guess if I can find out where to connect the 24V relay at the high/low beam switch, the rest would be easy, it think.
Stone, where did you find the 24V 130w bulbs?
Greg B, thanks for the lesson on the head light wiring, kind of messed up but good to know. Don't know why Toyota didn't just go with 24V head lights?
I was very hopefull to find an answer to my problem here

 

[Stone]

Stephan:

I put my voltmeter to the wiring harness under my steering column and found a couple of wires related to the headlight switch. There is a red wire with a green stripe that sees (+) 24v when the high beams are on. There is also a slightly fatter red wire beside it with a yellow stripe that sees (+) 24v when the headlights are on, but 0v when the high beams are flipped on.

Would you test your harness and see if you see that same thing on yours as in mine? If it is the same, then I guess you will have to switch the 24v relay from the (+) side and not ground. It seems to me a tap to the skinnier red wire with the green stripe leading to your relay coil will flip it when the high beams are on, and you can also then run a wire from the relay coil through an on/off switch and then to a (+)24v source to manually flip the aux lights on whenever you want. As insurance, I would personally put a diode inline with the wire tapping off of the red/green wire from the harness.

Does this sound sensible?

I didn't get my 130W 24v bulbs here, they came on my truck from Japan. Looks like these bulbs last a LONG time...as one light wasn't working, but it only turned out to be some corrosion on the base of the bulb that was preventing contact with ground. Cleaned it off and still worked. Looks like they've been there for years. The highest wattage 24v H3 bulbs that I've found locally so far have been the Hella 100W H3s from Lordco. Maybe some of the trucking suppliers have some higher wattage ones, I haven't had the chance to look extensively yet. Cheers.

 

[coldtaco]

Stone

Hey, thanks. I think this will work. Will check it out. Need to find a 24V relay now. Was wondering what size speakers you used in the cruiser? Was interested in a "component" speaker set-up that has the seperate tweeter and the extra little electrical box for each set of speakers. If you know what I'm talking about, do you think these will add more power usage out of the converter? Right now I have the cigarete lighter, stereo, cb on the inverter, it's the same one you got. Of course the cb is on only for road trips or wheeling and the cigarette lighter is used to charge the cell phone. Thanks again.

 

[Stone]

Components do produce very good sound, although high quality coaxial speakers these days are so good it's hard to justify the added expense and additional holes you need to make for components. They should not draw more current as it's the deck that is supplying the speakers with juice. I thought that the little box (crossover network) in most of these component speakers were passive...but even if you have active ones (I haven't seen one personally), they wouldn't take much current to work at all.

I have 6.5" Pioneer 2-ways on the front doors, and 6x9" Pioneer 4-ways in the rear panels. If you can find custom mounts to make 6.5" speakers sort of like a surface mount or shallow mount...you can mount 2 of those in the rear barn doors instead of on the sides in the rear and it will throw the sound at you better. I've seen this type of mount in some of the JDM 70 series.

 

[coldtaco]

Stone

Thanks. What's a JDM 70?

 

[Stone]

Japanese Domestic Market 70 series. All the imported BJ70, 71, and 74s.

 

[coldtaco]

Ah, I should have figured that out.