URNVS

I am helping a friend out with her 2005 CLK500. The car was in a front end accident a while back, and whomever put it back together did not do the best job with the wiring. Right now the ambient temperature shows -40.

The ambient temperature sensor and plug isnt where its supposed to be on the passenger side bumper. Does anyone know where the wires that go to that sensor come out of the harness, and what colors they are (a picture might be incredibly helpful)?

DanielFD

Thats what the sensor looks like. it plugs into the left side of the front bumper (if your looking at the car from the front) it looks like the sensor is missing completely, or its completely broken in half to give out -40. The wire comes out of the harness from the left (if your looking at the front of the car) of the engine bay and passes over the left wheel well (again if your looking at the front of the car).

URNVS

So its somewhere in that cluster of wires that goes to the headlights, fog light and radiator overflow tank?

Rudeney

I've tried checking WiS for the wiring diagrams, but I can't find the plug for this temperature sensors. I'm pulling the bumper on my CLK this weekend (finally getting it painted to fix all the rock chips in the paint from where I worked in an industrial area). I'll check the colors and report back.

DanielFD

I opened up the engine bay yesterday. couldn't find the wires correctly so cant help you out there. Your in Rodney's arms now..

Rudeney

OK, so while removing the bumper, I checked the wiring for the temperature sensor. It is connected to the same wiring harness as the right side fog light. It uses two leads - green and brown, which are also the same colors as the fog light, but the temp sensor is a much smaller gauge - maybe 20ga compared to 16ga for the fog light. That harness runs up the finder and connects to a loom of wire right in front of the coolant reservoir.

URNVS

Thanks!!! Ill pull apart the fog light wiring and dig those out

URNVS

So still no luck. I pulled out what I thought was the fog light wiring (the car has no fogs after the accident), but to me it looks more like a horn plug? I found a couple of other disconnected/taped up plugs as well. One was inside the passenger fender, and the other on at the side of the engine, behind the cooling fan. Any idea what these are for?

Can you post a pic of temp/foglight loom where it goes into the harness by the coolant reservoir?

Rudeney

No, none of those are it. I should have my CLK back this weekend from the body shop and when I re-install the front bumper, I'll take a closer look at the wiring and try to take some photos for you.

Rudeney

Wiring harness, right side fender





Wiring harness, right side fender, bottom bundle splits off the fog light and ambient temperature sensor





Ambient temperature sensor and fog light connector





Ambient temperature sensor

URNVS

Thanks again, I really appreciate it!

I ended up pulling the bumper and the headlight, and had to follow unwrap the loom all the way up to that joint in your 2nd picture to finally find where they had hidden the wires.

Rudeney

Good deal! I know pulling the bumper is a pain, but do it a few times, and it becomes a fairly easy task.

HETPE3B

I was missing the temperature sensor as well as long as the wiring to it, so this thread helped me a lot locating the 2 snapped wires, which I assume are for temperature sensor. Will find it out shortly if this is the case.
Now a have another mystery to solve - I need to find the wires for the left fog light. Can anyone shade some light what braid the wiring for the left fog light is coming out from? I need to find a clue where to dig in order to find another set of snapped wires...

clydem

Thanks for posting the pics.
I presume that's looking up from below with the bellypan removed?

My outside temp readings were spot-on until the 1st cold snap hear in NNJ
then I saw it display 70 and ever so slowly drop down until it hit 36. But the actual temp was more like 25.
Now it's always a bit higher than the actual outside temp.
So I'm guessing I need a new sensor.
Looks like an OEM is < $30 at advanced auto parts P4025378043OES
< $25 at autoHaus # 0075421318 (+ $10 s/h)

Thomast21

which side on the right it is it on the driver side or passenger side?

Fatz

Ambient temp sensor is on the passenger side for US cars.