I just did the fan switch mod the one recomended by shoebox and others the "ultimate fan switch mod" I found easy to follow and complete but I came up with a few answers. on my 96 lt1 . First I noticed that my car only had 2 harness connectors instead of 3 but I figured out the correct wires by studying a wiring diagram from a shop manual I have. Welll I got it wired and all hooked up after all of the install I flipped the switch. when I put the fans on high both of the led's came on and the fans turned onto high but the service engine soon light also turned on. the fans work fine but I am worried about the ses light. Im just wondering if anyone had this problem before and how you were able to fix the issue.

Thanks!
Ed

 

Yeah, I have a 96 and I just did the mod. Here's what else you need to do. Put a diode and resistor in series at the splice to keep the PCM from fouling up. You have to do this for an OBD II car. Here's the daigram.

http://csce.uark.edu/~jgbertr/rb/fan_sw_diagram2.jpg

 

The only thing you need to get rid of the SES is the 47 ohm resistors. The diodes are only needed if the LEDs don't work as expected.

 

I've found that with the diodes, the led's don't come on when the pcm turns the fans on. Just thought I would throw that out there.

 

THanks Alot for the input guys!

Just so I know before I go running to the electronics store what type of undesired operation would be caused by not using the diodes? I just want to have all my ducks in a row.

Thanks Again Guys!
Ed

 

Sometimes the LEDs might stay on after the car is off. If you use a switched 12v source for the LEDs, you won't have to worry about it. It just depends on whether you will use the fans when the engine or key is not ON. 96-97 fans will run by the manual switch when the key is OFF. 93-95 fans won't.

 

this is what I had to do for mine to work as well, it got rid of the SES light and cleared the code.