964 Horn problems
03-17-2007, 09:27 AM
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964 Horn problems
Hi,
I have recently purchased a '91 964 (such a great car!) and have a problem with the horn (and also a newbie to this list).
The car has a Momo steering wheel & when the wheel in in a particular position (about 30-40 degrees to the right) the horn goes off (yes - VERY annoying). It also does it on a hard left turn at exactly same position on the steering wheel (i.e 320-330 degrees to the left).
I have taken the bottom cover that goes arround the steering wheel & slid a sheet of paper between the horn contact (a springy brass metal strip) and the horn contact ring. The horn contact ring remains open circuit at any position, so it means the problem must be in the springy brass metal strip or in the various wiring looms on the back of it (i.e. where the cruise control lever switch, indicator lever switch or wiper lever switch).
Does anyone know where the connection from the springy brass goes to? I assume it must go to one of the connectors on the back of the levers, but I'm not sure which one.
Cheers,
Gary.
Perth
Australia
I have recently purchased a '91 964 (such a great car!) and have a problem with the horn (and also a newbie to this list).
The car has a Momo steering wheel & when the wheel in in a particular position (about 30-40 degrees to the right) the horn goes off (yes - VERY annoying). It also does it on a hard left turn at exactly same position on the steering wheel (i.e 320-330 degrees to the left).
I have taken the bottom cover that goes arround the steering wheel & slid a sheet of paper between the horn contact (a springy brass metal strip) and the horn contact ring. The horn contact ring remains open circuit at any position, so it means the problem must be in the springy brass metal strip or in the various wiring looms on the back of it (i.e. where the cruise control lever switch, indicator lever switch or wiper lever switch).
Does anyone know where the connection from the springy brass goes to? I assume it must go to one of the connectors on the back of the levers, but I'm not sure which one.
Cheers,
Gary.
Perth
Australia
03-17-2007, 11:56 AM
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Hi and welcome 
I'm not sure about the horn problem - it is likely the contact shorting to the brass ring at the positions you mention.
There are some disassembly photos here , perhaps you can clean up the contacts or reposition the contact so it does not short out.
Marc
I'm not sure about the horn problem - it is likely the contact shorting to the brass ring at the positions you mention.
There are some disassembly photos here , perhaps you can clean up the contacts or reposition the contact so it does not short out.
Marc
03-17-2007, 01:52 PM
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I think Marc hit it on the head. Aftermarket steering wheels sometimes have this problem if they are installed incorrectly. I used to have an Olds Cutlass with an aftermarket steering wheel. (I know... Apples to oranges) I had a similar problem. It turns out that there was supposed to be an insulating tube to house the connector and it wasn't there. I think I used a drinking straw and it solved the problem. If your steering wheel has an airbag you might want to take it to a certified technician. You don't want to set off the airbag accidentally.
Please post some pics of your Porsche and let us know about the fix.
Please post some pics of your Porsche and let us know about the fix.
03-20-2007, 09:03 PM
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Thanks for your help so far.
Well, I have narrowed down the fault to between the springy horn contact (at the back of the steering wheel) and the indicator connector pin 71 (from the diagram pin 71 on this connector is used to carry the horn contact siganl from the steering wheel to the horn relay). If I connect pin 71 to ground, the horn works fine. If I measure the resistance on the springy contact to ground, it closes when I push the button. This link is broken somewhere in between.
So the big question - does anyone know how the spriny contact links to the connector at pin 71. The connector appears sealed but maybe the fault is somewhere behind the springy contact.
Anway, I've put a photo of my car in the avatar (sorry - this is the best I have at the moment - try & get some better pics at the next club outing!).
Thanks,
Gary.
Well, I have narrowed down the fault to between the springy horn contact (at the back of the steering wheel) and the indicator connector pin 71 (from the diagram pin 71 on this connector is used to carry the horn contact siganl from the steering wheel to the horn relay). If I connect pin 71 to ground, the horn works fine. If I measure the resistance on the springy contact to ground, it closes when I push the button. This link is broken somewhere in between.
So the big question - does anyone know how the spriny contact links to the connector at pin 71. The connector appears sealed but maybe the fault is somewhere behind the springy contact.
Anway, I've put a photo of my car in the avatar (sorry - this is the best I have at the moment - try & get some better pics at the next club outing!).
Thanks,
Gary.
