Which wire to tap for Dimmer

[obxjeep]

I am wiring up my Uniden BCT15 scanner and I need to tap into a wire inside the dash that provides power when the parking/driving lights turn on. Thanks in advance!

[James76]

as far as i know all dash wiring inside the jeep is multiplexed, i had to go to the white/green wire under the main fuse box under the hood for parking lights

[obxjeep]

I'm not sure what you mean by multiplexed... I'm pretty good with wiring, but have never heard that term before :thinking: ... do you by chance know what color the wire may be coming from the switch? Thanks!!

[James76]

multiplex wiring is found in most Chrysler vehicles. Say for parking lights at the switch it may use one wire for both head lights and for parking lights. It may send 5.6k ohms of resistance for parking lights and say 1.3k ohms for head lights. the body control module reads this resistance and sends a trigger to the appropriate under hood relays to turn the circuit on. This is why in most cases use the basic 12v circuits found under the hood instead of the dash wiring. If you were to put straight ground to a multiplexed wire you could essentially fry the BCM :eek2: You may be able to find a courtesy light wire somewhere but i can tell you that the switch wires in the Jk ARE multiplexed :yup: So just run the wire out to the fuse box. When you flip it over it will be at the bottom and its white with a green tracer. It will test positive when the switch is on. :yup:

[obxjeep]

multiplex wiring is found in most Chrysler vehicles. Say for parking lights at the switch it may use one wire for both head lights and for parking lights. It may send 5.6k ohms of resistance for parking lights and say 1.3k ohms for head lights. the body control module reads this resistance and sends a trigger to the appropriate under hood relays to turn the circuit on. This is why in most cases use the basic 12v circuits found under the hood instead of the dash wiring. If you were to put straight ground to a multiplexed wire you could essentially fry the BCM :eek2: You may be able to find a courtesy light wire somewhere but i can tell you that the switch wires in the Jk ARE multiplexed :yup: So just run the wire out to the fuse box. When you flip it over it will be at the bottom and its white with a green tracer. It will test positive when the switch is on. :yup:

Well I definately learned a lot!!! Thanks for such an in depth reply! I will look for that wire tomorrow... is there only going to be one white w/green tracer wire under there? :D Thanks again!

[James76]

if you want to wait till tomorrow i can take a picture of it....it was the only one i could find...just use a test light if you dont want to wait tho. tip the fuse box towards the battery and itll be towards the bottom and towards the engine side....mine was sticking right out...so:) FYI Multiplex is commonly referred to as MUX

[obxjeep]

I should, keyword 'should', be fine finding it... thanks!

[James76]

10-4 :D Keep the shiny side up! :eek2:

[John L]

There is an orange wire with a grey stripe behind the center stack, it goes to the illumination for the climate controls. I've tapped into it for various reasons, maybe easier to get to than the underside of the fusebox.

[James76]

:crazyeyes: yeah i thought about that after i went to bed....the white green under hood is mainly for remote start and keyless entry use to trigger the parking lights but itll work for what hes wanting...either one really...:yup:

[obxjeep]

I'll probably use the one in the stack since my wire bundle going through to the engine bay already has 8 wires :D Thanks!!

[John L]

Are you getting the remote head with your scanner? A bit pricey at ~180, but it solves lost of problems.......

[James76]

any wire as long as its on the output side of the BCM is ok, which those console lights are :yup: