[s-cars] Autocheck after relaying headlights

[Wayne Dohnal]

>I cleaned the lenses and relayed the headlights on my father's car ('92) a
>few days ago, but as usual, the autocheck thinks there is a blown bulb due
>to the relay only being connected to the car harness on one side. How do I
>"fool" the autocheck system into thinking everything is OK?

Here's what I did in case you choose to do some cutting and soldering inside 
the autocheck module.

1. Get the plastic case of of the module.  #%$&#^!!!  After you spend an 
hour doing that....

2. Look at the component side of the circuit board.  Between the 2 vertical 
metal maze-looking components there are 2, inch-long wires flat against the 
board.  These are the low-ohm resistors used to sense current through each 
of the headlight circuits.

3. Turn the module over, board-side up, connector pins down.  Look at the 
solder pads along the bottom of the board, starting at the right.  Skip the 
1st 2 pads.  The next 2 pads connect to the ends of one of the headlight 
sense resistors, and the next 2 connect to the ends of the other headlight 
sense resistor. (verify this in case not all of the modules are the same).

4. Solder a jumper between the 3rd and 4th pad from the right, and another 
between the 5th and 6th pad, to shunt across each of the sense resistors.

5. Cut each of the 4 traces you just jumpered, cutting above the jumpers you 
just soldered in.  I don't remember how I did it, but it sure looks like the 
work of a cutoff wheel on a dremel tool.

The autocheck module now thinks the headlights are always off, and its other 
functions are unaffected.  I'm pretty sure I could successfully reverse the 
change if I ever wanted to.  You can obviously acomplish the same thing by 
fiddling with the wires under the autocheck module, or cutting the correct 4 
pins off of the module and inserting jumpers into the fusebox connector 
before plugging the module in.

Wayne Dohnal
1994 S4



-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.362 / Virus Database: 267.12.7/157 - Release Date: 11/2/2005