ALDL wiring OBDII

[dezertrat]

I have a 99 3400 out of a Montana in a desert pre-run buggy.

How do I wire my ALDL connector to the PCM?

The connector has four wires. Purple wire on #2 pin, black on #4 and #5 pins, and orange on # 16.

The pcm has a purple wire at c1-59 and a tan wire at c1-15.

My chilton manual says the plug should be wired different.

Also, how do I wire an autometer tach?

I have the white wire that exits the PCM at pin c2-8, but it does not work. Do I need a tach adapter from msd or something?

Thanks for any and all help.

Frank

[TheDirtyBen]

RE: ALDL wiring OBDII

to get tach reading you need to tap into, i believe, the white wire in one of the connectors that plug into the ICM mounted underneath the coil packs.