Can we do this? (aka The DIY Cruise Control Thread)

[CTScott]

Excellent pics! Let me scratch around them a bit and see what I can come up with.

[CTScott]

Originally Posted by CTScott

Excellent pics! Let me scratch around them a bit and see what I can come up with.

OK. To figure this out, we'll need the meter PCB to be hooked up to the car. What you'll have to do is turn the ignition on, and initially take 16 voltage measurements, then press your cruise on button and take the 16 again. If one of the 16 changes after turning cruise on, we'll know that that pin would drive the cruise LED if the car had one.

IC500 and IC501 are the "8 bit shift registers". Each of them can drive 8 LEDs. We need to look at pins 3 through 6 and 11 through 14 on each.

Pin 1 is the pin under the "1" after the IC50x label. In your picture which has the text upside down, Pin 3 is right above the middle of the 00 in IC500 and right above the 1 in IC501. In that view, 4, 5 and 6 are to the right of 3.

Pin 9 is at the top right in that view (next to the upside down 9). Pin 11 is two pins to the left of 9. 12, 13, and 14 are to the left on 11.

So, connect it up, turn the ignition switch on, and measure from a ground point to each of those 16 pins. They will measure ~0.5 VDC, or ~5.0 VDC.

Then, press your cruise on button and measure all 16 again.