No head/tail lights or turn signals, squirrel chewed ground at J4

Ah maybe we found our problem, so we don't have a ground on the White/Black wire at the switch?

 

If you

If you have power at that the ground wire.
Than you don't have a good ground.

 

No, it did not light up test light with (+) battery connected, so I connected (-) battery to pin 12 and got 9.3V on the digital tester.

 

Lets ground that pin through an incandescent test light and see if everything works.

 

The tester bulb does not light up, but the parking lights come on?

 

Is your switch in the park light position?

 

Doubtful, as the original issue was parking lights, but no headlights…….
But let’s hope they were just in park….

 

Well I mean we definitely found a problem because Pin 12 (White/Black) of the switch should be ground at all times...

 

In full-
Key off, HEAD shows 12V on 2 and 5, nothing on 1.
Key on HEAD 2 and 5 still 12V, pin 1 shows 2.71V.
Readings from HEAD do not change, DIM in or out, switch in any position.

DIM shows power on pin 1 even with HEAD removed. When HEAD is replaced, DIM pin 1 goes from 10.2V to 9.8.
DIM pins 4 and 5 show 12V when connected to (+) battery, but only with HEAD in.

Thanks a lot y'all, I'm getting sleepy, good luck, back in the AM.

 

Yeah. I know.
But why does/did the parking lights work?
But not the head lights.

I believe OP said the parking lights have always worked?

It’s the same ground wire………?

 

I've seen missing grounds do some weird shit so who knows but if the OP is on Pin 12 of the switch and the ground is missing we're onto something.

 

No, only get parking lights with switch full on, high/low/flash made no difference. I think I tried flash, will check again tomorrow..

 

How on earth is there power to pin 1 of the dimmer relay, WITHOUT the headlight relay being in?
The head relay feeds power to pin 1 of the dimmer?


WTF?…….Now I’m confused.

 

I believe IA1 pin 30, yellow/black, is connected to DIM pin 1, and IA1 pin 29 is connected to HEAD pin 2?
So... pins 29 and 30 maybe are shorted to each other, and a 12V power source?
The 2.7 at HEAD 2 and 9.7 at DIM 1 do add up to 12.4 volts...but I didn't think electricity acted like that.

 

There's an extra wire, not shown here, at the headlight/C11 combo switch.
Pin 18 has a dark green wire which is showing 9.7V of power, same as DIM ground pin 2.
Ooh! Found it in spreadsheet. It also shows 10.4V at ECU B5 pin 13.

Reminder, a new headlight switch didn't change a thing when plugged into the clip.

IJ1 pin 8 = Tail Light Switch Signal from Combination Switch (C11 Pin 18) to Body ECU (B5 Pin 13)

 

The IA1 pin 30 (Y/B wire) is connected to pin 2 of the Dim. Not pin 1.
IA1 pin 29 (White) goes to pin 1.

Also, where are you testing your ground from?
A body bolt, battery terminal, or from a ground wire?

 

And the Dark Green wire at Pin 18 is for the taillights. AKA - Parking lights

 

I typed it backwards, the spreadsheet says 29 goes to HEAD 1 and 30 goes to DIM 2?
(+)Battery terminal.

 

Shouldn't the green one be 12V? Instead of 9.7V @ C11 pin 18 and 10.3V @ B5 pin 13?

 

It does, I was wrong above.
I fixed it.

IA1-29 goes to pin 1 of Head Relay.