Transmission switch PRND32
01-10-2013, 04:41 PM
#61
Drifting
Great job Tony.
On my 90S4 I have a problem with the gear indicators also. The P and 2 don't light up. The rest work fine. I wanted to know if there was a location where each of the bulbs could be tested without taking the pod off?
On my 90S4 I have a problem with the gear indicators also. The P and 2 don't light up. The rest work fine. I wanted to know if there was a location where each of the bulbs could be tested without taking the pod off?
01-10-2013, 05:27 PM
#62
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It was Bobs write up on the bad circuit that was the clincher for me and fixed everything!
Im not sure how yours is wired but in the 87 i think the easiest spot is in the spare tire well. There is a connector there that you can supply 9-12v to and light up each individual light.
Only the "D" light was out on mine when i tested there, but i replaced the "P" light also as it sees the most use after "D"
Im not sure how yours is wired but in the 87 i think the easiest spot is in the spare tire well. There is a connector there that you can supply 9-12v to and light up each individual light.
Only the "D" light was out on mine when i tested there, but i replaced the "P" light also as it sees the most use after "D"
01-10-2013, 06:33 PM
#65
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It will be nice now as I may even allow my wife to drive it..in dire cases that involve extreme emergencys : )
01-10-2013, 06:48 PM
#66
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03-02-2024, 04:18 PM
#68
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My VERY BELATED Thank You to Tony and all the contributors to this thread. Reading it provided the incentive for me to analyze the same issue on my '95 automatic. Ultimately, it turned out to be the sender switch mounted on the transmission. Replaced it with a good quality lightly used one, and it's good to go for another 25+ years.
Thanks Guys.
For future owners who have a bad switch, replacement is easy - access is the primary problem. I had OE pumpkin resonators, but have replaced them with GT resonators. Thus, there is quite a bit of space between the resonator and the heat shield. I removed 4-5 screws out of the resonator mounts, leaving one at the front that was not accessible by any of my tools without removing the left side resonator/pipes. This allowed me to rotate the shield enough for my stubby fingered size large hands to access the shifter system on the transmission.
Removed the bolt that holds the shift arm (ball joint mounted to it at the top) to the transmission shaft. Slid that arm off then removed the electrical connector from the sender switch. There is a white locking clamp that needs to be rotated clockwise to release this connector. The connector can be pried from the switch CAREFULLY. There are two 10 mm head bolts holding the switch to the tranny. One at ~8 o'clock and one at ~2 o'clock. Remove these two bolts. and the switch comes right off. Reverse the process for installation of the new switch. Two 'YouTube' Mercedes owner commentaries on the site Mrmerlin suggested on another thread can be helpful (post # 4 here: https://rennlist.com/forums/928-foru...ty-switch.html ) , especially the one that shows how to orient the switch, as it is adjustable via slots where the two bolts are inserted.
Gary
PS: a new sender switch is now nearly $250 at your local Porsche dealer - Roger stated it was $98 15 years ago. INFLATION - WHO'D HAVE GUESSED THAT MIGHT HAPPEN!!!
Thanks Guys.
For future owners who have a bad switch, replacement is easy - access is the primary problem. I had OE pumpkin resonators, but have replaced them with GT resonators. Thus, there is quite a bit of space between the resonator and the heat shield. I removed 4-5 screws out of the resonator mounts, leaving one at the front that was not accessible by any of my tools without removing the left side resonator/pipes. This allowed me to rotate the shield enough for my stubby fingered size large hands to access the shifter system on the transmission.
Removed the bolt that holds the shift arm (ball joint mounted to it at the top) to the transmission shaft. Slid that arm off then removed the electrical connector from the sender switch. There is a white locking clamp that needs to be rotated clockwise to release this connector. The connector can be pried from the switch CAREFULLY. There are two 10 mm head bolts holding the switch to the tranny. One at ~8 o'clock and one at ~2 o'clock. Remove these two bolts. and the switch comes right off. Reverse the process for installation of the new switch. Two 'YouTube' Mercedes owner commentaries on the site Mrmerlin suggested on another thread can be helpful (post # 4 here: https://rennlist.com/forums/928-foru...ty-switch.html ) , especially the one that shows how to orient the switch, as it is adjustable via slots where the two bolts are inserted.
Gary
PS: a new sender switch is now nearly $250 at your local Porsche dealer - Roger stated it was $98 15 years ago. INFLATION - WHO'D HAVE GUESSED THAT MIGHT HAPPEN!!!
Last edited by Gary Knox; 03-04-2024 at 10:21 AM.
