URNVS

Hi, I am having issues keeping the fan going on my 05 CLK500. As far as I can tell, it will slowly spin up as the temperature increases, but once it gets to a point where it should be running on high, it pops the fuse. When its that warm, it will immediately pop another fuse as well, but if I let the car sit overnight to cool off, I can start the cycle over again.

Fuse 51 is only 7.5a, so it cant possibly be the one providing current to the engine fan. Does anyone know how the wiring for this works? Does 51 power some sort of relay that powers the fan controller? Where can I find the wiring diagram?

Plutoe

post your VIN!!

URNVS

2093751F150712

Plutoe

You may not understand the engine and AC electric suction fan--the fan only operates when the ECU senses a high coolant temp and or a high refrig temp-----if the fan comes on with a cold engine you have a fault!!


In any event use starfinder and look for PE5421p2106BA and PE0761p210197BA.


FYI: fuse 51 protects the relay in the circuit 15


My guess is that you have a couple of issues----do you have DAS

URNVS

I do understand the relationship between fan speed, coolant temperature, and refrigerant pressure. Here in Phoenix its going to reach maximum fan speed within 10ish minutes of driving :P

The fan does not come on with a cold engine, it does come on slowly as the car gets hot, and that increasing speed works fine. Its when the fan reaches a high RPM (car is fully warm) that the fuse pops, and at that point a new fuse will pop right away if I just swap it.

I do have access to DAS.

URNVS

Bumping this thread - temperatures reached 117 this week, and the fuse popping issue started up again :/

Any ideas what would cause fuse 51 to blow when the engine fan is on high?

bbirdwell

For your car the fuse assignment shows fuse 51 is used with the following:
-the instrument cluster. (Note: fuse 42 (7.5 amps) also connects to the instrument cluster).
-the Code 581 Comfort Automatic Air Conditioning; fuse 51 powers the sensors for the AAC.
---Fuse 51 connects to connector X85/9 to power multi-function sensor B31 directly and, via connector X28/26, the sun sensors B32/2.
---These sensors provide input to the Automatic Air Conditioning (AAC) control module. Fuse 51 does not power the AAC, fuse 41 (15 amp) powers the AAC.
---The SAM connector 19 provides the connection to the AAC's sensors.
-the Code 614 Bi-Xenon headlamp units left E1 and right E2 (not sure what it does).
---the SAM connector 24 provides the connection with the headlamp units. The wire is spliced to connect fuse 51 with pin 3 of both xenon control modules.

It's not clear which fuse you are talking about. Only fuse 51? Or the humongous fuse powering the suction fan behind the radiator?

The engine suction fan is controlled by the ECU and the fan's fuse is rated at 125 amps; should be #5 in the pre-fuse block(?).

If fuse 51 is the one blowing, I would look at the climate sensors first, xenon modules second, and the instrument cluster third.

I can't do much more to assist long distance but this gave me something to do over my lunch break.

Good luck.

URNVS

Only fuse 51, all other fuses are fine.