HDJ81 Headlamp/Foglamp Wiring (1 Viewer)

[carbon60]

Hi All,

Just installed a set of Depo headlamps in my 1994 JDM HDJ81. Works great.

The OE harness switches the filaments on the H4 bulb for hi/lo. The OE setup is with fogs in the other sockets.

So, I want to do a few of things:

1. Setup the currently unused H1 to come on with the hi beams, which will likely require a new harness and relay triggered off the gate or output of the OE relay that drives the H4s.
2. Use the OE dash control for the fog lamp circuit to power my LED aux lights, but I also want them to only be energized with the high-beams are on.

This would be way simpler with the wiring diagram, which I can not find anywhere. Googling "depo +hdj81" produces zero results.

So, does anyone know where I can get the wiring diagram that will show the OE relay setup for the hi/lo H4 and fog (H3?) If not, how about some suggestions from someone who's done this, before, to get me on the right track?

Thank you,

A.

 

[IanB]

For the high beams, some HDJ81's have an unused H1 harness taped up (my '91 had it, I couldn't find it on my '93), making it plug and play, no additional harnesses/relays required.

For the aux. lights, there's no reason you can't use the factory switch and wiring to activate them, I don't have any input other than maybe just use the switch and don't worry about wiring them to come on with the high beams only, you might find that extra effort isn't required, you might even find that's not how you want them to work. If you live where it snows, high beams aren't always the answer, you may want to be able to run the low beams and aux. lights only, which you can still do if you leave it as is.

 

[ThaiCruiser]

What did you do with your old headlights?

 

[carbon60]

For the high beams, some HDJ81's have an unused H1 harness taped up (my '91 had it, I couldn't find it on my '93), making it plug and play, no additional harnesses/relays required.

A friend's '92 did indeed have that, but I can't find it. Happen to know where to start looking?

For the aux. lights, there's no reason you can't use the factory switch and wiring to activate them, I don't have any input other than maybe just use the switch and don't worry about wiring them to come on with the high beams only, you might find that extra effort isn't required, you might even find that's not how you want them to work. If you live where it snows, high beams aren't always the answer, you may want to be able to run the low beams and aux. lights only, which you can still do if you leave it as is.

Food for thought, thank you very much.

What did you do with your old headlights?

I have them in boxes. You want them? They are JDM RHD spec.

A.

 

[IanB]

A friend's '92 did indeed have that, but I can't find it. Happen to know where to start looking?

They were taped up in the headlight wiring harness on my '91 and I don't remember them being difficult to locate, like I said I was unable to locate them on my '93.

 

[ikarus]

Bumping an old thread. I've thought through this a little but want to run it by others since electrical isn't my forte..

I had the JDM HDJ81 headlights with internal fog lights. I've since converted to quads using the H4 connectors. That leaves me with two unused H3C connectors from the JDM fog lights. (gray plug on the right)

I would like to add LED fog lights, and I don't mind if they act just like the OEM fog lights - automatically turning off when the brights are on, etc. Also, I would like to do this by using the factory wiring and factory fog light switch.

In my research I have found that the stock bulbs were 55W H3C halogens:

Using the Amps - Watts formula, (55w x2 bulbs / 12 volt system) we get a total of 9.17 amps on the stock fog light system. Also the fog circuit has a 15A fuse.

So, the LED lights I'm looking at are 30w with a 2.4A draw and with 2 fog lights we get a total of 4.8A - much less than the stock halogen setup.

I'd like to keep my additional wiring to a minimum. Any reason I couldn't use the factory wiring and switch to install these LED fog lights like @IanB says a few posts up? (as opposed to new wiring with a relay or tying into a Switch Pro type system)

I found a bunch of guys on TacomaWorld that have done this but they were less fact-based and more "I wired up a 50 inch light bar using stock wiring and only blew a fuse once so I'm good" -based.

 

[HDJ80L]

@ikarus While a 15A fuse doesn't neccessarily mean that the whole fog light circuit is capable of running 15 amps (the fuse is just there to protect the wiring in case of overload/short circuit) it's perfectly fine as long as your new lights stay below or equal the wattage of the stock bulbs.

 

[ikarus]

@ikarus While a 15A fuse doesn't neccessarily mean that the whole fog light circuit is capable of running 15 amps (the fuse is just there to protect the wiring in case of overload/short circuit) it's perfectly fine as long as your new lights stay below or equal the wattage of the stock bulbs.

Cool, that's what I was thinking, thanks.