Heat/AC panel and fuse 48

[Mike V]

Are you willing to sell the spare module?

[smoothhd]

Well haven't updated this for a while, too many other projects in work. I was finally able to check all of the wiring mentioned in the TSB i found and all checked normal. No shorts, chaffed wires or loose connections. So, I took others advice and put a 10A fuse in place of the 7.5A, as much as I hated to do it that way. All seems well so far.

[BeckMule]

Just curious if the original poster (or anyone else) has an update on this, as I have the exact same problem: fuse 48 blowing on 2005 X5 4.4 with no apparent wiring problems. Am considering trying the 10A fuse solution, but am curious as to whether anyone has had any problems using a fuse with higher amperage in this scenario. Am grateful for all help and comments.

[CTSportX5]

I just posted about this recently. In my case (interestingly also a 2005 X5 4.4) my aux water pump has gone bad. I unplugged the Aux WP and have not had a fuse blown since. It has been weeks. I have not yet replaced the pump, just unplugged the electrical harness to it. Come winter time this will need to be replaced as it effects low RPM heating of the cabin.

http://www.xoutpost.com/bmw-sav-foru...-not-turn.html

[BeckMule]

Thanks for the follow-up. The 48 fuse stopped popping when the heather control valve was disconnected. I'm going to drive around for a while with it disconnected before replacing it just to make sure it is indeed the culprit. If not, obviously I'll have to start disconnecting other components. I'll update the post when I have more information.

[BeckMule]

Not the heater control valve, as the fuse blew after about a week. Because the fuse does not blow reliably (could be a day, could be a week, who knows) the repair shop tells me there's no way to diagnose the problem that wouldn't involve expensive guessing as to which component could be the culprit. Very frustrating, as I never know when the fuse will blow and whether replacing the fuse will fix it only momentarily (in which case there is no heat/AC) or for a week. Open to any and all suggestions.

[CTSportX5]

Have you tried unplugging the aux water pump? My fuse hasn't popped since.

[BeckMule]

Any way you can tell me (or better yet, show me with a pic) where the plug is? Or will I need to have the shop do it? Not a DIYer, by any means.

[BeckMule]

For posterity, I am updating this post in the event it may be helpful to others in the future.

After MUCH diagnostic work, a quality indy shop was able to determine that I simultaneously had failures in the aux water pump AND the heating control valve. Replacing one or the other did not fix the problem (aux water pump caused fuse to blow on start; heating control valve was also sticking and causing fuse to blow subsequently). Both parts were replaced and fuse has not blown in about a month. Will update further if there are any changes.

[nebilex]

I am perhaps late to post here but I did the 10A as a temporary fix and it has not blown since. How much was the aux water pump and heating control valve parts + labor? With winter not to far from now, I am thinking the 10A fix is going to back fire.