WTB - FC01-66-167 Headlight Switch Harness

[infernosg]

Originally Posted by Islandplans

Hi infernosg,
I appreciate the info on changing the pins on the S4 harness - it just looked a little difficult after examining the manual - I'm fairly new to this. For instance: the S4 dimmer clip has a pin labeled 'HB' that does not exist on my S5. Would that be left in?

My S5 clip has a pin labeled with parenthesis as '(E)'. It is the only pin with the parenthesis. Do you know what that means since there is also an 'E' without parenthesis.

Hopefully I can lay everything out clearly...

Note, the FSM and Wiring Diagrams aren't always consistent how they depict connectors (viewed from the front or back) so I may have the pin-outs reversed.

Even though the connectors are pinned differently the wire colors are consistent. From the Wiring diagram I deduced the following functions for each wire:

B (black) = ground, "E"
B/R (black w/ red stripe) = turn signal switched power source, "TIG"
G/R (green w/ red strip) = left indicator power out, "SL"
G/W (green w/ white stripe) = turn signal cancel signal, "SC"
G/Y (green w/ yellow stripe) = right indicator power out, "SR"
R/G (red w/ green stripe)*
R/W (red w/ white stripe) = dimmer switch power source (from headlight relay), "HR"
R/Y (red w/ yellow strip) = dimmer switch input from hi-beam (dimmer) relay, "DR"
X = blank, no pin

*There are two R/G wires shown in the wiring diagrams and from what I can tell the S4 uses both but the S5 only uses one. Both use one of the R/G wires as the source for the switch illumination "IL" but the S4 also uses it for some "HB" function, which I've not yet determined.

From the S5 FSM, Section T, pages 22 and 23, the pin-out order is:

Blank E Space Space TIG SR
SC (E) IL HR SL DR

or in terms of wire color:

X B _ _ B/R G/Y
G/W (B) R/G R/W G/R R/Y

Again, I can't recall if the FSM references the connector from the front or back. It's best to have both harnesses side-by-side before starting, if possible. The unknown is the second R/G wire. I know my '89 S5 sub-harness had two R/G wires and the wiring diagram in my paper copy of the '89 FSM shows a second R/G wire going into the dimmer switch straight from the headlight relay. However, it doesn't give any purpose for the wire; it just shows a line leading to a box with no connector callout and no reference in section T of the FSM. The S4 wiring diagram is the same as it being a power wire straight from the headlight relay but it is included it in the connector call-out and gives it the "HB" function in section T of the FSM. In the later S5 diagrams this same wire goes to the ECU from the headlight relay. The only information regarding that is the ECU sees 12V at pin "3L" when the headlights are on and 0V when they're off. I imagine this serves some kind of of "idle up" function to increase alternator output when the headlights are on. I have confirmed the hi-beams still function without the ECU plugged in but I can't confirm if the second R/G wire with the "HB" function is required. For now, I have it connected to the (E) slot on the connector.

Originally Posted by Islandplans

Are the pins only moved on the dimmer clip and not the 'blue clip' the wires are attached to?

How do I physically move the pins? Just pull them out, and move to the proper slot?

To my knowledge the only connector that requires pins to be moved around is the one going into the dimmer switch. Everything else appeared to be the same. To remove the pins you'll need a small pick-like tool to lift a retaining clip inside the connector. I use one of those really small screwdrivers used to repair eyeglasses. Insert the pick into the front of the connector and push up/down (depending on the connector) while simultaneously pulling on the wire. If you're pushing the right piece the pin will come right out with little force.

Originally Posted by Islandplans

Sorry for all the questions - just a bit lost. Since I would have to buy a harness anyway - even to change the S4 - I thought it would that much simpler to buy the proper one if available.

Thanks again.
Mike

No problem, that's what these forums are (supposed) to be for and what originally brought me here instead of some of the other rotary forums.

When I was searching for the S5 harness I only found one place that had a new one for sale (MazMart) and they wanted a ridiculous price for it. I found a used S4 sub-harness on eBay for less than $20. It was a no-brainer for me.