Fellow electrical gurus! I need your help! Here is what I've got.


I did the 35w HID retrofit with morimoto D2S hi/lo projectors (Write-up coming soon BTW) and they are all ready to rock. I just need the bulbs and to do the wiring. The wiring is where I am running into an issue however.

Measuring with my multimeter, I determined there was a considerable voltage drop across the stock headlight harness, so I decided to power the ballasts directly off the battery. I am going to wire the projector solenoids directly to the headlight harness ground and highbeam power wire so that the projectors will switch between hi/lo along with the high beam switch. Simple and straightforward. The ballast wiring however is where I am running into a problem.

Obviously I cannot wire the ballasts DIRECTLY to the battery or the headlights would be on all the time even when the car was shut off. I have a couple of 30A generic relays just laying around I was going to use and power the relay coil off the headlight harness low beam wire so the HIDs/ballasts would switch on off with the headlight switch. The problem is that the stock wiring in the car kills voltage to the lowbeam wire whenever the highbeams are switched on. So while the projector solenoids would still function the HIDs would turn off when the car was in high beam mode. I could splice the high and low beam wire into each other so the relay coild would always be powered when the headlights were on but then the projector solenoids would always be getting voltage and the HIDs would be stuck in high beam mode.

The electrical fanatic in me is bothered by not being able to figure this out. Am I missing something? Other than crawling under the dash and modifying the high beam switch at the base of the steering column so it doesn't kill voltage to the low beam wire, I don't see how this is supposed to work.

One other possible approach is using 2 relays per headlight, so it would relay battery power in both high beam and low beam mode, but I think this is kind of sloppy. I'd prefer to keep it clean and simple.

 

I did a similar retro with the morimoto mini H1 projectors...I just got the H4 relay harness from TRS and got an H4 to 4656 adapter so that I could just use the stock low beam wiring to power the relays. The low beam 4656 also has a high beam function, so the stock wiring to the low beam bulbs will provide the signal to switch to high beams as well.

 

Thanks but I looked at the body wiring diagram and figured it out.

All that is needed is to cut the tan wire on the high beam switch at the base of the steering column and splice it into the yellow wire at the switch.

This way, the low beam power wire will still switch on/off with the headlight **** but will be bypassing the highbeam switch so that the highbeams cannot interrupt power to the lowbeam wire. The highbeam wire will still turn on/off like normal.

 

no capacitors? helps maintain the proper voltage needed to power up and run the ballasts. go to radio shack you can run one from the relay for $1.00

 

I'm sorry but I don't see how capacitors are going to be needed. Wouldn't that be the same concept as running a capacitor for an amp?

Depending on the load, a capacitor can only typically supply a charge for seconds, if that. Once the capacitor has depleted It's charge the voltage will fall back to the next highest source.