Fuel door switch not working

[DaviesKeymaster]

It seems fairly common for the only way to open the fuel door is with the mechanical release on the b-pillar. I have three 780s and none of them have a working button on the dash.  (Actually my 1991 will work about 20% of the time.)  Any idea of the source problem? It seems to be electrical as after several attempts the latch mechanism will click.  Any ideas how to repair?

[Andrea Salata]

Mine is not working either, at some point i tought it never worked..

[DaviesKeymaster]

Mine worked back in 1995 when I got the car and gradually stopped working. Anyone had experience with this repair?

[GuillaumeParticipant]

It works perfectly on my two 780.
I think your problem can be repair easily:
– It’s a mechanical problem? The linkage is good?
– It’s an electrical problem? Try to solve it with a multimeter.

Here is the schema:

Please use a multimeter to check where the electricity arrives:
– The ignition switch must be on position 2
– Is there 12 volts between the ground and the motor?
– If no: is there 12 volts between the ground and the switch?
– If no: is there 12 volts between the ground and the relay?
– If no: does the fuses 12 and 14 are ok?

[DaviesKeymaster]

That is good to know. I’ll go through the steps and see what is going on.  What is odd is that it isn’t consistent so I’m thinking it must be a bad connection at some point. Thanks for posting the steps

[christopher]

It has been my experience that the electrical portions of the release are working. Its the solenoid that actually opens the door that is not. I took mine our cleaned it up and put it back in and it has been working ever since.

[christopher]

Adding on my above comment, New fuel door/trunk solenoid.

http://www.ebay.com/itm/311756424763?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[DaviesKeymaster]

Thanks  Chris. Good idea I’ll pull the unit and make sure the mechanics are working with the solenoid in addition to confirming the electrical connections

[BertoneParticipant]

Hi,

My fuel door electric opening system did not work either.

To test were the fault was, I put 12 volts on the top orange cable (there are 2 and both are orange) that go to the opening switch on the dash, and the hatch opened up.

Hence 12 volts was not reaching these cables….I checked the relay (sits left to the OD relay) but it worked fine…clicked when I turned on ignition. Opened it up to see if I could find any other issue….but no…12v were coming out from pin 87 when triggered.

Then I looked at the gray plastic connector on the relay box…and amazingly the orange wire going to the switch was connected in a wrong position on the gray connector. I took out the cable with its spade connector and moved it up one position…and then it all worked!!

Incredible but true…at the factory they had connected the outgoing orange cable in the wrong place on the relay plastic mount.

The relay is a “small one”with a “steel metal” look..part number 1259926.

Hope this helps in case you also have problems with the hatch…

Btw…the entire fuse/relay holder comes out if you unhook a little black latch to the left…then just wiggle the entire piece out.

Be careful not to disconnect any cable….could be a nightmare if one cable comes loose and you do not know were it should go. He, he…

 

 

 

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