[07gray335i]

2007 bmw 335i e92. My water pump fuse keeps blowing. The fuse located in the passenger side engine bay under the white cover. 30 amp fuse

Long story short, I was on my way home from a 13 hour drive from North Carolina to Michigan and about 40 minutes from home the orange over heating symbol came on then the car went into limp mode. I pulled over and scanned the car. Had a bunch of water pump codes.
Towed the car home and replaced the water pump, when I first started the car the water pump still wasn’t working. After more searching I found the fuse blown in the engine bay. Replaced that then the car worked fine. A couple days later the fuse blew again and it keeps happening.

I pulled the power wire running from the fuse to water pump and everything was fine on it, no melting or cracks. Looks like the other power wire splits and runs into the interior. That one also looks to be in good shape and not grounding anywhere

Anyone know what else I should check? I’m not sure where to go from here

[07gray335i]

Anyone

[cdm244@gmail.com]

Since replacing the pump also gives you new pump electronics the issue seems like it must be a short to ground between the fuse (output side) and the pump connector. With the pump disconnected try measuring: 1) resistance between the fuse and the +12 v pin on the pump side; and 2) from the fuse side to ground. The first should be less than an ohm or so and the second should be way up towards infinity.

[07gray335i]

I have already checked the entire power wire from fuse to water pump. Nothing was grounding out on it. And I also added extra insulation to that wire

I should also add that the fuse doesn’t blow instantly. It only happens at random times while I’m driving, some days it doesn’t blow at all. It does it sometimes while I’m just cruising going 25 or on the highway going 70. Not really a pattern of when it blows.

[gbalthrop]

Originally Posted by 07gray335i

2007 bmw 335i e92. My water pump fuse keeps blowing. The fuse located in the passenger side engine bay under the white cover. 30 amp fuse...

According to TIS circuit diagrams, the 335i BEFORE 3/2007 had a 40 Amp fuse for F07 in the E-box, and the later 2007 models built 3/2007 on had a 50 Amp fuse in F07 slot. When the pump goes to Max speed (max Amp draw) you are probably blowing the 30 Amp fuse, and there may be NOTHING wrong with the system, just too low Amperage fuse.

Early 2007 Diagram:
https://www.newtis.info/tisv2/a/en/e...ooling/dJL5OHc

Late 2007 Diagram:
https://www.newtis.info/tisv2/a/en/e...ooling/wzLX20U

Please let us know what you find,
George

[M_Torx]

Had exact same problem it's the water pump return it get a different make

[E92guio]

Originally Posted by 07gray335i

I have already checked the entire power wire from fuse to water pump. Nothing was grounding out on it. And I also added extra insulation to that wire

I should also add that the fuse doesn’t blow instantly. It only happens at random times while I’m driving, some days it doesn’t blow at all. It does it sometimes while I’m just cruising going 25 or on the highway going 70. Not really a pattern of when it blows.

Did you end up figuring out what was wrong. I’m having the same issue on my 07 335i

[gbalthrop]

Originally Posted by E92guio

Did you end up figuring out what was wrong. I’m having the same issue on my 07 335i

What is build Month/Year, and the Last-7 Characters of your VIN? With that information, we can provide correct wiring diagram & fuse chart for your vehicle. MANY electrical changes effective 3/1/2007 in middle of 2007 model run.

If a fuse blows, WHAT NUMBER FUSE, and WHAT AMP Rating?

If you have Scan Tool, or Diagnostic Software such as INPA or ISTA, please identify, and indicate if it can do Activation/ Triggering of the Coolant Pump.

George