Joehank7

2005 E55..just bought 2 weeks ago,
Anytime I buy a car I replace battery first. If it needs it or not, just for peace of mind..
Yesterday car would not start, totally dead. Managed to get in trunk and jump it no problem. Prior to that I noticed navigation disc player in trunk was always making noise even with the car off. I thought that was the culprit so I unplugged it. Go back in the house and an hour later I hear what sounds like a leaf blower outside. Imagine my surprise when I see my radiator fan spinning at top speed! Mind you car has been off for an hour, and wasn't even brought up to temperature after I jumped it.
I thought maybe this has got to be the drainage problem. So I unplugged the fan. Came back out 30 minutes later, plugged back in and fan starts spinning again! Unplug it and go look for location of fan relay to check that.
Plug wire back in prior to checking relay and fan stays off.
Could a bad relay cause this behavior even with key off?

Ls1toAMG

First thing I would try is unhook the battery and charge overnight. Then hook it back up and drive the car. THEN try to locate a problem. Chasing electrical gremlins in this car with a low battery is not going to work.

Joehank7

Drove it around for an hour today..no issues. I think water got all over the aux battery( bc the cabin filter housing is missing).., then traveled down on the wires

Ls1toAMG

Cool. Hope it works for you. There should be no water able to get in. Check to see if the previous owner opened up the vents on the back of the hood or your molding around the hood has been messed with

Joehank7

I'm talking about the vents on the back of the hood. They don't open or close..they are part of the hood