Another n00b's cautionary tale. If you've ever wondered what an auto tranny inhibitor switch looks like inside, here you go. I'd rather be showing you a pristine functional switch but all I have is a broken one. The loose fragments in the pic below are part of the commutator, or wiper arm. Those fragments were the collar which held the wiper onto the splined shaft. The splined shaft is rotated by the fork on the outside of the switch. Just visible in the pic below, 2 black fork tines under the switch housing. So how does one break an inhibitor switch ? Too easy. When re-installing the shift linkage to the transmission the correct first step is to put the shift lever in Park. Then attach the linkage to the bottom of the shift lever. That way, when you tighten the nut which holds the linkage to the tranny selector shaft then the shaft can't turn. Below is the selector shaft, the switch was above & behind it. The lever in the pic is the one which engages the fork on the inhibitor switch. I was too hell bent on finishing to get out from under the car & put the shift lever in Park. So when I swung on that nut the selector shaft turned clockwise and the fork for the inhibitor switch followed it. I assumed there would be some sort of travel limiter to protect the switch, wrong x 10. The switch can be removed with the tranny on the car. Hardest part is freeing up the looms enough to allow you to pull the switch out. Either grow some tentacles or remove the starter. I hope this helps to stop others from making an avoidable mistake. Cheers from Mick. A special thank you to Tektrader for the Tech support via phone.:thumbup:
bad luck mate. if it makes you feel any better i pulled an engine together with the tranny and didn't disconnect the linkage, even though i pulled at least 4 engines before the same way.
Ah well, I was determined to learn about all of the sub-systems on the car. This fiasco has forced me to learn about diagnosing auto trannys, I've never owned one before. Prix of things aren't they ? Don't worry, I'd find ways to break a manual too.
A Hollywood ending. I bought a used switch from a GQ Patrol transmission, off a wrecker. The local Nissan dealer could supply one for $149 which I thought was OK but there was a 4 week wait. The only external difference is in the wiring loom. Original on the left, GQ Patrol on the right. The options were to shorten the 2 wires for the 2 pin plug or re-use the existing bakelite cover with loom. I went with the 2nd option. I opened it to check it's condition, clean it out & lube it. Those three springs are tiny. All it would take for a switch to fail is for one of the springs to weaken or break. The stationary contacts in the Patrol switch were in the same locations as in the damaged original switch. Here's the wiring colour assignments. While we're at it, for anyone needing to test the switch's continuity without removing or dismantling it - Refer to page AT 86 in the FSM, the 8 pin plug you'll be putting your multimeter on connects to the grey socket on the lower right in the below pic. Put it all back together, installed it on the transmission, no further issues. Hope this is useful to others some day.
