NSB Switch failing or electrical connectors?

[kachurak]

Well, if I had any hair left, I'd have pulled it out by now.

The last few days I've had some pretty cold weather (15F degrees or so) in Watertown, NY. I noticed that my shift lever would shift into gear with a little bit of effort.

Yesterday morning, I went out to the truck, started it right up, went to put in gear (R) and was able to do it, again, with a little effort (resistance). Put it into (D), again, a little resistance. Moved the truck about 2 feet forward, and it stalled. Not sure why, so I put it in (P) again and attempted to restart it. Well, this time, it wouldn't start.

Realized that the shift lever indicator didn't show any gear change, nor the highlight of the indication of what gear it was in. Flashbacks from this happening before, led me to believe it was the same thing again. The truck will crank, but never turn over and start. I knew the NSB switch (GM part # 29540479) was affecting it, so I located another one ($121, United Auto Supply, Cicero, NY) and put it on the truck. figuring it would resolve my problem and get everything back, it failed. Same thing, it will crank but never start. Something is obviously making the truck think it's in gear and won't crank (what the dealer said). I know mechanically operating though, the truck will move when in neutral, but not in any other position when I change the shift lever, so mechanically, it appears to be ok.(?)

So I'm really stuck on this guys, not knowing where to go with it. I guess what I'm looking for is any input as to what could be happening, if the connectors or any other electrical problems could be causing it. I get no indication on the service engine light, don't hear any additional chimes or anything other than normal. The only thing I can think of is maybe the wires somewhere are shorting, but it seems to look fine. Does anyone out there know what the 4-pin and 7-pin connectors that connect to the NSB switch should show for voltage? Any ideas on what else to do here woud be great - Thanks in advance!

 

[shortcircut65]

i think i understand what your saying, but amuse me if you could. if you go under the truck, and remove the shifter cable, then manually shift the truck with a pair of pliers, the display is all screwed up? the reason im asking is i had a simmilar problem with my truck. the shifter had a little bit more "tension" on it than normal, but the display would be all screwd up. it ened up being the cable was almost snapped off in the splice right under the driver door. replaced that :smash: and all was well. i thought it was the NSBU switch, and ended up replacing a good one for a bad one right out of the box, but got that squared away. hope i was some help,

Ken

 

[kachurak]

shortcircut,

will definitely take a closer look tomorrow. It's supposed to be cold and raining, of course, I'll be wet, but I'm taking the day off to try and resolve the issue. Will try what you said about shifting it manual and let you know when I've tried it what the result is.

At this point, anything can be a help. I'm just wondering, after tonight, all it wants to do is crank and not start. (?) I was thinking perhaps, now a fuel filter issue? Put on 28K since buying the truck and haven't replaced it yet so it's probably in need fairly soon anyway. Was told it has 2 filters. Is this correct?

 

[shortcircut65]

that would be a good thing to do. mines creeping up on 10k, and i need to replace. these thrucks only hve the one under the hood. i too heard that there were two, but more knowledgeble minds than mine said only one.

mine would start, you just had to have it in the right gear to start it. i didnt have the crank, but no start issue.

Ken

 

[kachurak]

Well, I gave up and put the truck in the shop on Wednesday morning. Haven't heard anything from them yet because of the holiday weekend but they said I will have something Monday morning regarding the issue.

 

[Sparky8370]

Sounds like you are having more than one issue here. When I did my NSBU switch, the resin that had been over heated was all over the pins. I cleaned mine the best I could with electrical cleaner and a plastic brush. I think there is still some on it because it was stuck in there the last time I tried to take it out and clean it. I didn't want to pry to hard and snap it in the cold weather. I also applied di-electric grease to mine.
I'd look into a fuel or security issue to get it running so that you can then determine the transmission problem.

 

[kachurak]

Result of the no-start was a bad connection to a ground apparently according the dealer, although I could never find it. That's why I was getting erroneous readings on dashlights and such. Electrical gremlin I guess. Thanks for all that responded.