4L80E Neutral Safety Switch......again

[anotheridiot]

I know Big Al just got the 4L80E for his build. Our 2003 Work van is the express 3500. This is the fourth Neutral Safety switch I am changing. First one was discount store, no choice, bad weather needed the van. That one lasted 30 days. Had an order for Rock Auto after I bought that one and got the AC Delco added on so that one was no down time. That one lasted about 6 months. Rock Auto didnt have AC Delco anymore, so went with the Standard since it cost most thought it was better made.

this morning, wont start, dont check the battery, dont check if the lights were left on, turn the key to on and see the shift indicator under the 2 again. What the hell happens to this thing? Anyone had a similar situation? Anyone know the wiring to splice in a toggle switch? Thought it could be an added Kill for switch for the builds, or just bypass this damn thing for when it doesnt fire in the snow so I dont have to get it towed to the shop.

[STINEY]

I haven't had that unfortunate experience, but I will be paying close attention to this thread. We have a '06 3500 Express 12-passenger, hope it doesn't start puking switches!

[BigAL]

I would replace the connectors that plug into the switch, you're probably getting to much resistance and it's burning up the switch.

[Beagle]

they should be sealed... are you using any grease on the connector by any chance?

[anotheridiot]

I would replace the connectors that plug into the switch, you're probably getting to much resistance and it's burning up the switch.

did you buy a harness from somewhere or are you replacing an electronic trans?

I went to GM Parts after searching for AC Delco again there were three that were supposed to fit. At least that way you can enter the vin number and get the actual part that should have come with the truck. Dont know how far away they are, so there is probably time to find the connectors.

[anotheridiot]

they should be sealed... are you using any grease on the connector by any chance?

no grease. you mean like dielectric grease?

[Beagle]

yep... just curious. Some folks won't put together a connection without it. Supposedly not supposed to do it without some high $$$ specific type / viscosity. I never have, just curious.

[BigAL]

did you buy a harness from somewhere or are you replacing an electronic trans?

I went to GM Parts after searching for AC Delco again there were three that were supposed to fit. At least that way you can enter the vin number and get the actual part that should have come with the truck. Dont know how far away they are, so there is probably time to find the connectors.

Nope not replacing an electric trans, Monte's came with 200-4r's, I got a TCI EZ TCU to control it, and not sure if I have to use the neutral safety switch on the trans or not, since the trans did not come with one. Though the shifter I'm looking at does have the neutral safety switch built into it, so I will probably go that route.

As for the connectors, 4l80e's had a problem with them burning up, one common problem is the connectors getting fused into the sockets on the safety switch where you can't remove them. If you keep burning up safety switches it is most likely do to to much resistance in the circuit.

[anotheridiot]

This neutral safety switch is the no start, shift indicator on dash (electronic) and it also lights the reverse lights at the transmission. I really dont know why they did it, with column shift the standard rotating column.

We had questionable wiring at the top side speed sensor connections, never had any discoloration at the connectors.

[BigAL]

Here's a couple of wiring diagrams for the two connectors on the switch.

[anotheridiot]

I know the switch is the reason the truck wont start because the shift indicator goes to a gear other than P or N. Turning the key and moving the column shift does nothing for the lights. Does it look to you like those are the range signals on the 4 prong connector or something in the ECM?

I just wonder because it looks like getting power to either B or G would allow the starter circuit to engage, where going C to E would just bypass the entire shift mechanism, but if that ground is not picked up thru the switch to the ECM the rest of the circuit might not allow the truck to run.

I just go back to that POS toyota I was working on, when I put power to the temperature switch the starter turned. Wouldnt run, but starter engaged and turned. I guess I will back probe to jump and figure out where I can bypass this when it wont start, because some of the problem might not be in the switch at all, but wiring to the ECM.

Oh, that GM part number, just referenced to the same AC DELCO switch that I bought before. Still made in mexico like the water pumps.

[anotheridiot]

new switch, same problem, damned connectors cost more than the switch. Looked like there was moisture inside, sprayed the old connectors, let them dry, added the dielectric grease too.

[anotheridiot]

still waiting for the connector, but before I pushed it back out of the shop, I went under and just got ready for the new connector, cut the duct tape like cloth tape over the connector wires, (theres bad idea #2 using tape that fills with water) then just spread out the wires and pointed the 4 transmission range wires in four opposite directions and indicator went back to park. So it seems its just that connector which is closer to the ground and "only" the 26.00 part. sprayed some of that plastic dip stuff over them since thats all I had ( I didnt have any liquid electric tape) and didnt want to yank on wires by taping. So I guess thats lesson I should have learned before I changed out the first switch and the first place for anyone to look when the indicator goes haywire. Makes sense that the neutral safety switch is not bad since it did not start in 2, but you have these encased and hermetically sealed circuit boards out in the weather I guess first gut feeling is its bad. Probably just unplugging the connectors and plugging them back in is enough to move the shorted wires out of each others way so you get the sense the switch fixed it.

[anotheridiot]

well, that time it lasted three years almost four months. Jeez this is unbelievable.

[Dan Barlow]

The more I hear about 87 and up cars the less I like 'em .