7 replies to this topic

[RealSlow]

More wiring issues! So during my drive yesterday, I lost headlights, high beams, instrument lights, tail lights, and rear fog light. 1994 JDM SPI. 

 

Test light says the brown wire at the headlight switch plug is getting no power, and that fuse 7/8 in the 4 fuse box under the hood is getting no power to either end. I've been staring at wiring diagrams all day, but I'm terrible at reading them. Brake lights work, horn works, turn signals and hazards work. My current guess is maybe one of the relays is toast, or maybe a ground came loose, but not sure if that would lead to no power at the switch. I'm also going to pull part of the dash apart and try to chase the brown wire back and look for breaks.

 

Man, I hate wiring.

[68+86auto]

From the factory, the brown wire is never fused. Unless they did something crazy on SPI/MPIs and didn't follow the colour coding properly.

There should be a join in the harness where one brown wire splits out for a couple of things, maybe this is your failure point.

Edited by 68+86auto, 06 November 2024 - 04:04 AM.

[brivinci]

Not sure how different JDM SPi are to RoW cars but on my UK 94, 7/8 fuse is a red to red/black wire. Brown is fused at 3/4, being brown (3) to purple (4).

The brown should come into the lighting switch to provide power. There is a red and a blue wire that come off the lighting switch from the 2 other terminals and provide power to the Rear (red/red black) and blue for the Front via the dip/dim switch.

[68+86auto]

Brown is fused at 3/4, being brown (3) to purple (4).

 

Purple is fused from the brown supply. Brown is not fused. I'm not sure if this is what you meant to say? That fuse has nothing to do with the headlights or tail lights. It is primarily used for the courtesy light.

[Designer]

 brown (3) to purple (4). 

 

White Knight (10) to Black Queen (15)    

[RealSlow]

I eventually gave up and tapped into power for the rear defroster switch, as I could never find a break. If I'm remembering correctly: test light showed no power at 7-8 or 3-4. As far as I could find, everything aside from headlights, instrument cluster, and taillights was working. So it appears that the brown power into the switch broke somewhere.

[RealSlow]

From the factory, the brown wire is never fused. Unless they did something crazy on SPI/MPIs and didn't follow the colour coding properly.

There should be a join in the harness where one brown wire splits out for a couple of things, maybe this is your failure point.

Do you know where that join is?

[68+86auto]

 

From the factory, the brown wire is never fused. Unless they did something crazy on SPI/MPIs and didn't follow the colour coding properly.

There should be a join in the harness where one brown wire splits out for a couple of things, maybe this is your failure point.

Do you know where that join is?

 

 

The harness needs to be untaped to find the join. Double check that you don't have power on the brown wire before going further.

 

On an 80s mini, I think I found it above where the washer bottle is located. It splits out to feed the starter relay bolted to the crossmember bracket.

The SPI could be in a different location. Have a look at the diagram to confirm that the wire splits out and what it feeds. It will be located before any of those components.

Edited by 68+86auto, 08 November 2024 - 03:59 AM.