hey everyone. I have an 87 Trans AM. I need some advice on headlight wiring.

Im currently doing an HID upgrade. NOT the wrong way by just slapping them in halogen housings. Im using infinity FX35 projectors with TSX clear lenses. My issue is I want to use the hi/lo shutter thats on the projectors. It requres a 12v signal to a solenoid when the high beams are on. But it doesnt change the light..its all one bulb (bi-xenon).

My question is, is there a simple way to have power stay on the low beam circuit, then when I click to high beams, have the 12v come through the high beam wire without shutting off the low beams???

In other words, I need my low beams to stay on with my high beams. This is usually only needed in case with separate lights for hi/lo. But since I need to power that solenoid, and I dont want to have the ballasts turning on/off to do so, I figured someone here might know how to do it. Probably simple as using a jumper wire somewhere.

I should also mention that Im going to be upgrading the head light harness to a relay set up with a larger gauge wire. Just to help with the ignition requirements of the HID ballasts and igniters.

Any ideas?? I might even be able to accomplish this when I build my new headlight harness...havent thought about that yet.

Thanks!

Justin

 

I guess one way is to pick off power to the ballast from the wire going between the light switch and the hi/lo switch..

 

Ok...did some thinking. I think this idea should work... I made a quick sketch of what I want to try. The solid lines are the normal low beam circuit with a relay added. Then the dotted line represents where the power will go when the high beam switch is hit.

This might result in a very brief loss of power to the ballast...but it shouldnt hurt anything. Im going to look into this with the HID guys before building the harness.

Anyway..here is the sketch.



I attached the PDF..just incase its hard to read.

Justin

 

From what I can see the hi & lo are shorted together. You'll need a diode going from the hi to the lo side, where there's a dotted line now. If you also add a capacitor across the relay coil, you won't get any brief power loss when switching.
I take it you don't want to add any wiring from inside the car.

 

Sorry...I should probably make a separate diagram...or change the line type for the two circuits. When the switch goes from lo to hi...the lo side is not getting power anymore. I just added the dotted lines...but I should mention that the solid line coming from the lo part of the switch will shut off. Actually...even if the power didnt shut off the lo side, it wouldnt short. Because its all positive to positive. Im not dead ending to ground anywhere that doesnt have a load to work with (relay, solenoid, etc).

As far as a capacitor...now you are beyond me. haha. That would be nice to try to incorporate in though...

And you are correct, Ide like to take care of this solution outside of the car. Here is why... The original headlight circuit is perfect for controlling relays. And if I can make a harness thats plug and play, then if for some reason I want to go back to stock, its as simple as un-plugging it all and reinstalling the halogens. I guess if there was a simple solution that is easily reversable that didnt require hacking into too many wires inside, Ide probably check that option out. But I need to build an upgrade harness for the headlights anyway...so thats why I wanted to try to make it work with that.

Thanks for your input by the way!

J.

EDIT: Shoot...you are right. I see what you mean now about the shorting... When the lo beam circuit is engergized, the high beam circuit will be too. Thanks for point that out... Back to the drawling board!

 

It's a hassle to break into the dash/ steering column so I understand the PnP concept.
Ok, if you want to do w/o the diode, you'll just have to add an extra relay so you get two in total.
Connect one coil to lo, the other to hi, and their contacts in parallell.
It generally takes a little longer for a relay to drop out than to pull in, so this way you migh not get a power glitch at all.

 

Hey man thanks for your help... I just finished re-working the diagram. I added another relay, and then saw your suggestion. I should be able to make the harness nice and neat even with the extra relay.

I have the high circuit powering both the coil in the relay and the solenoid. The solenoid on the projector has very small wires, so Im assuming it doesnt require much current...should be ok for my stock high circuit to power it.

I made two diagrams...just to make it easiers to look at. This should work out ok. The HIDs dont really use much more power after the initial fire up. So the upgrade harness is really just to aid in the start up of the bulbs.

Look ok now??

Low beams...


High beams...

Justin

 

Yep, that should do it, good work.
It's actually become identical to a halogen upgrade kit now, exept of course for the solenoid and the relay contacts being wired together instead of going to the separate filaments.
You could even do the parallelling of the relays on the ballast side of the secondary lamp sockets instead, connecting the now unused hi-beam cavities to the hi-beam relay (just like a halogen kit would have been).
That way, if you ever got trouble with the HID units you could then easily swap to 100W halogens instead, w/o having to rewire anything.
There are often many ways of achieving your goal when it comes to electr(on)ics.

 

Hmm... I like the idea of basically making a halogen upgrade harnes...with a shutter solenoid provision. That actually sounds much better. Ill have to give that some thought.

What exactly did you mean by parallel the relays on the ballast side? Do you mean make the "unused" high beam sockets energized under high beam conditions, and just run the ballast 12+ wire to that as well as the low?? So basically, branch a second power wire off the ballast power wire...

If thats what you mean, it sounds like a simple idea, and Ide probably like to do that.

J.

EDIT... Here is how I took what you suggested... Looks like it will work and will work good if I need to swap back to halogens. I actually have a set of 90/100 watt halogens, that I havent installed yet due to the wiring. So worse comes to worse, I sell my HID project and just do upgraded halogens.

Thanks for the brainstorming help!

 

Yes, that's just what I meant. You'll get a dual purpose harness that way. It's a neat solution.

 

Beautiful... Thanks for your help man! Ill just build the harness just like I did on my jeep. Except Ill add a single wire weather pack connector for the solenoid hook up on the high side. And then ill just modify the HID ballast wires to work like the diagram. Totally plug and play, totally removable. Also, if I cant get it to work like I want, I can sell that as a completely plug and play kit...should net me a sale much quicker!

Now I just gotta wait for the projectors to come in so I can see if I can get them to fit into a 6054 housing..and still fit in my headlight bucket. If I can swing it, Ill get started on the harness. Ill probably start a new thread dealing with the HID install...and Ill put pics of the harness in it.

J.