Sunroof drains plugged now fuse blowing

[Cheri]

Hi, I started a thread a few weeks ago about the rain water that got into the backseat due plugged sunroof drains. Got that problem fixed but now the #20 fuse keeps blowing. That fuse controls many things including the A/C. The mechanic said it could take up to 3 or more hours just to find the problem. Just wondering if someone knows how I should handle this problem. Thanks

[David325e]

Bump this for you. Is any wiring below the fuse corroded because of the water damage?

[Cheri]

Thank you. No, it looks fine under the fuse. I guess the water did the damage under the back seat where it flooded. Somehow maybe it shorted out a wire that leads to the fuse box...??? I don't know. I wish I knew how to find the short and tape it up.. I will try to get someone to use that tool that tests for voltage. I don't really know what I'm talking about and I can live without the A/C even though I'm in KS. But, I want to maintain this car as long as possible...I do love it. I suppose my only route is to take it back to the mechanic. I was hoping it would just fix itself after it dried out...wrong. Thanks again!!
Hey, coming back with an edit...is there a fuse in the back possibly. The fuses I'm dealing with are under the hood.

[tim eh]

The A/C won't work, the instrument lights either. The number 20 fuse blows instantly...I did hear a ding noise like it worked for a second. So, the water damaged something and now it will be difficult to find the problem, right? The mechanic that cleared the sunroof said it would take hours to even find the problem. The check control module or something like that??? Help please.

Well at least your mechanic is looking at the right circuit. F20 is connected to the ihkr and the check control module. It is also connected to the 'ding'. i would also suspect a short in the ihkr (controls heat/ac) as it can carry a pretty high load. The check control module is in the front power distribution box, so I doubt it is the unit itself.

which instrument lights are you talking about?

There are some more fuses and lots of wiring under the backseat you might want to see if you can find any more clues down there. And of course if you are playing with wires that you are not 100% sure of you would disconnect the battery while playing....

.. don't want to discourage but it could take a long time, especially if you are not sure what you are looking at, but it's certainly worth having a look so at least you know for yourself what kind of damage happened down there. a schematic would probably help you a lot...

pdf '94 wiring diagram here-> http://www.e38.org/e34/e34_94_etm.pdf
big file! 15MB or something.

[Cheri]

Tim eh, I am pretty sure it is the instrument cluster/check control lights-though the tail lights work. I do have a manual that tells me which fuse goes to what. But, the F20 controls many things but only some of those things don't work. So, see, I don't know how things work. Just some things got shorted out? I looked in the back seat at those fuses and everything looked good. Thanks for the diagram. I will study it and see if I can learn a thing or two. Thanks again!

[Sherman]

Whendoes it blow? As soon as the cct livens or only under load, like when the AC cycles on? Start eliminating sections of the cct, like before and after the components it powers, then break out any junction points etc. It's the only way to narrow it down, otherwise you just end up replacing connectins and wiring until you stumble accross the right point, which you may never if there is a short within a bundle somewhere.

[Cheri]

I've only tried to replace the fuse once and nothing was on-AC, etc. and it blew instantly. I heard the ding and then I heard it fry. Thanks Sherman.