I'm looking for the wire to turn on the park lights at the light switch itself, which in past experience was a brown wire(+). It doesn't respond. There is 12v coming from the alarm brain. Do I have to run a separate wire directly to the drivers park light for this van?

Could you also maybe explain the difference between multiplexing & class 2 Databus systems.
I do realize that the OBDII is a GM standard and is not used in this van and I realize that multiplex system is tapping into the ECM or cars computer to add an external device such as alarm etc

I generally stick to sound and video systems but do the odd alarm or starter

 

Thanks, should make for a happy customer. None of my wiring installation software has any of that info, so I guess this is where experiance pays. Thanks again!

 

I found a thin gauge white wire coming from the actual relay for the park lights on the fuse box under the drivers seat.

I applied a relay to switch my postive park light wire from the alarm's brain into a negative and tapped into the white wire.

I could not find the positive brown at the fuse box.

I had orginally tried to tap into the back of the light switch but the one wire I found for lights had negative while the lights were off and positive during park lights & head lights. Orginally there was no "at rest" at the parking light wire which made me feel that sending a pulse of positive to this wire might either short out the brain's park light wire or damage the van's electronic switch.