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Old 06-16-2011, 03:45 PM   #1
Mongo
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Question Symptoms of a Bad Ignition Switch?

I have been having the same recurring symptoms lately whenever I come out to start my car (I now drive it once or twice a week as it is back to being a garage queen):

1) Erratic Fuel Gauge that won't register at all sometimes

2) Brake Pad Light on intermittently

3) Blower Fan Intermittent

4) AT Shift lights intermittently on

5) Sputters and Stalls on cold start, then fires up on third attempt to start with LOTS of black smoke (flooded engine)


The only thing I have not replaced in the 10 years of ownership is the ignition switch. I did press on the plug connecting to the switch yesterday causing my AT shift lights to work in the gauge cluster again.
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Old 06-16-2011, 06:43 PM   #2
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I don't see anything in your list that involves the ignition switch. You solved the AT light thing by fiddling with the pod connections. Fuel gauge could be the same issue or in the pod itself. The gauge contacts with the circuit board in the pod can be iffy. There are collections of ground wires for the pod gauges under the pod and the fuel sender has a ground point in the spare tire well. Intermittent brake pad warning is almost always one of the sensor connection blocks near the calipers not fully seated. You may still have an LH issue causing the over-rich cold start.

All your problem circuits except the fueling issue pass through a 14-pin connector (T19) near the CE panel. Also, they pass though the central informer under the driver footrest. You may want to check wiring in those areas.
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GP White '89 S4 - 269K carefree (well, almost) miles, creeping up slowly on 300K. Motor unopened and original TT bearings.
'87 rear resonators; '83 LSD; PKlamp on TT, Bilsteins, 2002 996 wheels; Momo Club 4 steering wheel; H4 Hi/Lo HID headlights; HID driving lights.

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Old 06-16-2011, 06:46 PM   #3
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Oh, I missed the blower fan...check the seating of the relay.

Does it ALWAYS work on defrost or is that intermittent too? If it always works on defrost, it could be the resistor pack.
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GP White '89 S4 - 269K carefree (well, almost) miles, creeping up slowly on 300K. Motor unopened and original TT bearings.
'87 rear resonators; '83 LSD; PKlamp on TT, Bilsteins, 2002 996 wheels; Momo Club 4 steering wheel; H4 Hi/Lo HID headlights; HID driving lights.

If you live in North or Central CA, join our group at Norcal928.org
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Old 06-16-2011, 07:05 PM   #4
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Hey Bill, actually when the blower fan started acting up, the first thing I checked was the relay and put a new one in. Still works intermittently.


Is the 14-pin connector you mention the one under the hood on the passenger side under the charging post cover?

EDIT: I found in a search that it is not the 14-pin in the engine compartment, but rather one that is in the area as you said, but only 7 or 8 pins are actually used. Is there a picture of what this looks like?
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Old 06-16-2011, 08:08 PM   #5
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Quote:
Originally Posted by Mongo View Post
Is the 14-pin connector you mention the one under the hood on the passenger side under the charging post cover?

EDIT: I found in a search that it is not the 14-pin in the engine compartment, but rather one that is in the area as you said, but only 7 or 8 pins are actually used. Is there a picture of what this looks like?
My recollection is that it is up by the glovebox, perhaps a bit hidden. I found it once a long time ago.
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GP White '89 S4 - 269K carefree (well, almost) miles, creeping up slowly on 300K. Motor unopened and original TT bearings.
'87 rear resonators; '83 LSD; PKlamp on TT, Bilsteins, 2002 996 wheels; Momo Club 4 steering wheel; H4 Hi/Lo HID headlights; HID driving lights.

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Old 06-17-2011, 10:46 AM   #6
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Interesting how my 'overly rich' cold starts disappeared. I tried it 3 times yesterday with no rich running issues. I wonder if it's because it was sitting for about 2 weeks on a maintainer. I will have to check that ground in the back of the car for the fuel gauge and work in the passenger footwell area to find that T19. I'm not sure what I would be specifically looking for on that connector other than exposed wiring.
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Old 06-17-2011, 11:15 AM   #7
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I had some of the exact same symptoms.

Erratic Fuel Gauge that won't register at all sometimes? - Yup

Brake Pad Light on intermittently? I have my sensors unhooked, so I don't think that would light up on mine - but my "stop lamp" light would stay on, even after I pushed the brakes.

Blower Fan Intermittent? - Yup

My wipers would also not work and the headlights would turn on, but not pop up. Also, my key would get very hot.

Re-starting the car would sometimes erase all the faults and the car would be normal.

I turned the key slightly backwards while the car was running one day and saw the "stop lamp" warning go off, fuel gauge jumped back up, etc.

Searched here and came to the conclusion it was the ignition switch. Planned on pulling the pod to change a few bulbs and was going to change the switch then.

Got to thinking "hummmm.....it does seem as if the tumblers are sticking - I wonder if a shot of Deoxit would help?". I've used this wonderful spray on window switches (just sprayed it in from the top - did not take apart the switches at all), door interior light pin, and the sunroof rails and it made them all work like new.

One shot of that directly into the ignition tumbler and I haven't had the problem since - it's been about 3 weeks now and it has not come back. My key is no longer hot and it bounces itself back (or sits in the correct position - don't know how it really works) when starting the car.
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Old 06-17-2011, 03:29 PM   #8
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Jeff:

That's a bit weird since the key tumblers and the electrical section of the ignition are separate.
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GP White '89 S4 - 269K carefree (well, almost) miles, creeping up slowly on 300K. Motor unopened and original TT bearings.
'87 rear resonators; '83 LSD; PKlamp on TT, Bilsteins, 2002 996 wheels; Momo Club 4 steering wheel; H4 Hi/Lo HID headlights; HID driving lights.

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Old 06-17-2011, 04:29 PM   #9
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Could the Deoxit have lubricated the tumbler enough to make it sit back in the right spot (as is when I would slightly turn the key back)? Does the position of the key have any effect on the ignition switch?
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Old 06-20-2011, 11:07 AM   #10
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I found the T19 this weekend after pulling out the EZK and LH. The thing looked like new and no wires were damaged (no corrosion or sheething missing). This is probably good news. I was in there before doing a CE panel removal for cleaning and I recall seeing that same connector with no issues either.
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Old 06-20-2011, 12:02 PM   #11
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I had similar issues. Tried a new switch and still nothing, but now it would not start. Turned out to be Ignition Module.
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Old 06-20-2011, 12:02 PM
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