My #9 fuse keeps blowing and I need my AC and horn

[Jason]

Seems like the little things keep piling up... anyway, my #9 fuse blew around memorial day weekend and i didnt think anything of it. the it happened again yesterday, so i replaced the fuse last night, when to use the horn and AC this morning and it got fried, so i replaced it again. Then after hiting the horn once, it went out again. I'm assuming the problem lies in the steering/horn area. Besides the airbag connection what other wires could short it?
TIA
J

[DanH]

Check the wires where they plug into the horns, they become brittle after 15 years...

Also try unplugging one horn at a time to see of one or the other is causing the fuse to blow.

[Beemr750]

just remove the horn relay first and try it,if it does'nt blow,you know from where you have a problem!

[Rory]

Good news!! You now get to practice taking off the front bumper :-)

http://www.nmia.com/~dgnrg/page_20.htm

BTDT and it is pretty simple and straight forward. The Bentley outlines a test that you can run on your radiator mounted sensor by jumpering a couple pins. If you don't have a Bentley then I can look up the specific test between the three pins for you, but it will confirm that your resistor is bad. But I assume that based on the symptoms that this is the problem. Good Luck

Best,
Rory

[glen-sj]

Same thing happened to me on my 92 525ia about three years ago. At the suggestion of the Indy, I had them install in-line fuses at each of the the three circuits before it comes together at fuse #9; horn, AC and aux water pump to isolate the problem. It turned out to be a faulty aux water circuit, changed out the aux water pump and the problem was solved. The #9 fuse hasn't blown since.

glen-sj

[Jason]

I was gonna look up the procedure tonight in the bentley, cause i wanted to do the aux fan resistor. but i thought all it involved was grille removal. is the bumper something i can do by myself?

[MBXB]

Here'w Winston Fong's Grill Removal Page:

http://home.comcast.net/%7Ewinstonfong/repairpagessite2/frontgrillremoval.htm

[Derek A.]

I just bypassed the resitor - If the fan is gonna run - then let it run fast - no reason to do anything half assed :)

[winfred]

the problem with that is the fan draws too many amps to start in high and will kill the fuse, you can reach the resister from the bottom behind the spoiler, theres a plastic piece that needs to be removed then you can get to it. whenever the fan is called on for high speed it's allready running in low and doesn't need that much extra power to spool up, i've measured the starting draw in high to be around 55 amps but it's only for a second or two so the fuse can take it but it gets worn a little every time and it will pop


I just bypassed the resitor - If the fan is gonna run - then let it run fast - no reason to do anything half assed :)

[winfred]

that's what i did and almost 3 years later i am still running on one horn


Also try unplugging one horn at a time to see of one or the other is causing the fuse to blow.

[Dan in NZ]

Try unplugging the aux water pump. Mine was binding and making that fuse blow. Has been fine since disconnecting the pump, don't seem to need it anyway.

[Derek A.]

the problem with that is the fan draws too many amps to start in high and will kill the fuse, you can reach the resister from the bottom behind the spoiler, theres a plastic piece that needs to be removed then you can get to it. whenever the fan is called on for high speed it's allready running in low and doesn't need that much extra power to spool up, i've measured the starting draw in high to be around 55 amps but it's only for a second or two so the fuse can take it but it gets worn a little every time and it will pop

Its probably compounded by an older fan with higher resistance. I replaced my fan with a custom fit ( read much cheaper non BMW fan ) last summer and it has been working great. No issues with the fuse kicking out.