Fuse blowing 89 911 Carrera

[Yan2947]

Just got my car back from the body guy who did an amazing job on sume rust. I had rust on the cowel, door pilars and behind the rockers on the passenger side. The windshield had to be removed to repair the cowel. For some reason they touched the sun roof button and it opened. When they closed the sun roof the fuse blew (16 amp). I put another fuse in and opened the sun roof a bit. It opens fine. Once you hit the other half of the button to close the roof the fuse blows. The windows were down so I had to put in another fuse. They operate without problems as long as the same fuse is good. The manual doesn't show a fuse panel diagram. Does anyone have one or picture of one? Another interesting thing is that the relay for the door/key in the ignition is buzzing with the key in the ignition. Relay is 9116181000. I pop the relay and no buzzing. Not sure what the relay controls in order to diagnose the problem. Any help would be appreciated! Why these 2 symptoms all of a sudden?

thanks!

Yan

[Joeaksa]

Pull the switch out and make sure the terminals behind are not touching metal.

[Yan2947]

I pulled the switch out. I pulled the switch off the plug it connects to. No sign of burning. All wires were connected. They seem fine. Could the switch itself be broken? Opens but the fuse blows when you press the switch to close? Could removal of the windshield come close to any wires? The windows on the door work fine until you blow the fuse by closing the sun roof. I would assume they are on the same line.

[Tigerrat]

I'd check the sunroof motor/mechanism. Sounds like something is overloading the motor and it the fuse. Maybe just cleaning, lubricating the rails would do it. Ken

[Rot 911]

As to the fuse panel diagram, you should have a black plastic cover over the fuse panel. The outside of it has the diagram.

Do you live in Europe? Only ask because it is fairly rare for a late model 911, residing in the U.S. to have that kind of rust absent a car that was wrecked and then repaired.

[Yan2947]

Ken - As soon as you touch the close button the fuse trips - immediate. I will look to see if anything is in the way and lubricate the rails.

Rot 911 - I live in NY. The car began its life in Michigan where I got it. The rust seems to be a common place even on newer cars. The rust is hopefully all gone and covered with the right protection and kept in a garage! The cowel rust seems fairly common according to posts as well as the door pillars. Nothing protects the back of the door pillar. Everything gets thrown up in there and the same for behind the rockers. The nooks and cranys back there seem to hold every pebble and piece of dirt. Since I know of the area it will be an area of constant cleaning.
Still haven't solved the sun roof issue. I will get at it now.

[Yan2947]

Rot 911 - the outside of the fuse panel has a holder for a diagram. I never had the diagram. Bought the car used.

[Yan2947]

I hand turned the sun roof closed using the panal and dial inside of zippered headliner and it turned like it was brand new. Could the switch be bad? That simple?

[Yan2947]

I bypassed the switch. Hot comes in, ground and two that leave the switch. The line that operates the opening of the roof functions well. The line that leaves the switch trips immediately. It would make sense that the "closing power line" is being grounded somewhere or could the motor be bad on the closing end?

[dshepp806]

Might you disconnect the connection to the motor then actuate the switch? In other words, remove the load and see if she still blows the fuse via switch actuation......would tell you if that wire is grounding out somewhere...you'd certainly be removing the motor from the equation......

or take an "ohmeter" approach to test............

..just a thought.

Best,

Doyle

[Yan2947]

Doyle,

To disconnect the motor is it that one plug one sees when you unzip/take of the cover for the sun roof and right in front of you is a plug with 2 black wires coming in to a plug/connector then leaving with 2 wires I think green and some other color? I believe it goes to the motor. There are no other wires correct?

[Yan2947]

Has anyone ever followed the wire from the sun roof switch to the motor to see where it travels? It seems pretty hard to get to once it leaves the switch.

[Yan2947]

Doyle,

I disconnected the motor for the sunroof. I put a new fuse in. Hit the open button and the fuse did not blow. I then hit the close portion of the button and it blew immediately. This brings me back to wonder if putting in a new windshield, cutting around the window to get it loose could have brought the body guys knife anywhere near the positive lead for outgoing "close" button. If so how do I trace that wire????? Does anything come off easily in the dash or does the window need to be removed to find the issue?

thanks again to everyone for the kind help

Yan

[Yan2947]

Doyle, Ken and Kurt,
thanks for the help. I crawled into the hood area and was able to see where they did the cowel repair. The welder's wire was sticking down and pierced the wire housing for the sun roof in 2 places. Pulling the welder's wire out didn't help yet. I would assume it probably fused a ground in there with the positive wire for the "closing" wire and such shortening it out everytime you hit the "close" button. I have to somehow take the protected sleeve off and fix the grounding issue that is inside the sleeve. At least I know where it is. Getting rid of the motor out of the equation pin pointed where to look.

thanks again all!

Yan

[dshepp806]

Good work!

Welders' wire was in there? why?

Maybe you can save some fuses at this point by hanging an ohmeter on that "closing" DC buss wire to ground (no need to actuate the switch, as I feel this grounding exists AS IS,..simply awaiting instruction to cross the switch's contacts upon command!) Disassemble this sleeve that you suspect and start moving stuff around (with the ohmeter attached) until the ohmeter shows you the (proper) open circuit measurement of infinity. Then, you will have found the culprit.

Just 2 cents, however.

Again,..good work.

Best,

Doyle

[Yan2947]

Doyle,

its all fixed. Disassembly of the sleeve was impossible. After removing part of the headliner it was found that the sleeve was deeply burried and could not be easily gotten to from above. Moving the sleeve around from the front trunk was enough to dislodge whatever connection to a ground there was. Whatever piece of welder's wire could have been grounding out the positive lead has been removed out of the equation and currently all is better. Thanks for all the help everyone!

Yan