Reverse light trigger/NSS?

[Zoro]

What triggers the reverse lights on an '84 Wagon and where can it be found, in the shifter or the trans? Just noticed my reverse lights are out and the bulbs appear to be good.

Went looking thru the parts store catalog for the replacement part and it's listed as the NSS. Does the NSS on these cars pull double duty or does it use two identical parts at different places?

[vangremlin]

Its the neutral safety switch, located on the transmission.  Its pretty easy to replace it, other than spilling some transmission fluid.  You also have to pull the skid plate.  The part is pretty cheap also.

[Zoro]

Its the neutral safety switch, located on the transmission.  Its pretty easy to replace it, other than spilling some transmission fluid.  You also have to pull the skid plate.  The part is pretty cheap also.

Gotcha. Car still starts no problem which is what I don't get.

[BenM]

You may want to take a multimeter to the wiring before you pull the switch if it still starts.

The part of the harness that goes to the switch on the transmission is pretty long and should be in some wire wrap. Heat and oil over the years can break that down and make it easy for a wire to be pinched.

Check that the bulbs' ground as well. There's just a small metal screw grounding things in the back, and if it's corroded then lights will find some interesting ways to ground back there.

I think it's probably just the switch, but it doesn't hurt to eliminate the free fixes first. There are three contacts on the switch one that grounds for the solenoid, and two that connect for the reverse lights.

[TLC87Eagle]

Either Neutral Safety Switch or could be a fuse under the dash that blew too, although other things would be out too.
Mine blew once and it took out the back up lights, turn signals, and the rear window defroster, but not the wiper for some reason. Not sure what's all wired into that fuse.

Another unlikely possibility could be a bad ground somewhere.

I used to have problems with my NSS connector, had to lay down and push it back on until I got a new one from the Nest Store. But mine wouldn't start when it fell off, it would fall off on the drive home, and I would notice the back-up lights were out when I backed into the driveway.

[Zoro]

Tore apart the rear panel today and the reverse bulbs are intact and good looking plus all the other lights back there are doing their respective things as they should.

Blinkers work as does the rear defrost but the rear wiper is INOP. I believe this is due to the wires in the dash pulling off the switch and me being too lazy to rip the dash apart again.

Did not check the fuses but I'll give that a shot tomorrow.

Went up under the car and found the switch. Appears to be on the driver's side front of the transmission with 3 wires leading in and is rather greasy and grimy.

Does the front driveshaft need to be yanked to replace the switch or is there just barely enough room?

Thanks!

[shanebo]

I replaced one of those switches years ago and if memory serves me it was a pretty tight squeeze.

[vangremlin]

Does the front driveshaft need to be yanked to replace the switch or is there just barely enough room?

Thanks!

Now that you mention it, I think you do have to pull the front drive shaft as well as the skid plate.  I just did this job last summer but have already forgotten what all was involved. 

[Zoro]

Now that you mention it, I think you do have to pull the front drive shaft as well as the skid plate.  I just did this job last summer but have already forgotten what all was involved. 

Always gotta put those bad memories behind ya!

[vangremlin]

Always gotta put those bad memories behind ya!

Exactly, because once I got to thinking about it, I remember how the cap came off the u-joint, and the needle bearings went all over!!  Somehow, I was lucky enough to find them all when it came time to put it all back together.  Some of them fell in the crease of my creeper, don't know how I ever spotted them!

[carnuck]

First, pull the plug (it's on the back corner of the trans on the driver's side, just above the pan) and put a jumper wire across between the 2 outer wires of the plug (center is a ground for the solenoid) With the key on, back up lights should come on. If not, the problem is NOT the switch (since it's bypassed) Check both of those pins for power (one is power and the other goes to the backup lights) No power = blown fuse or broken/unplugged wires. There is another connector by the trans dipstick tube.

[Zoro]

Tore it down today and now that it's warmer it's actually MUCH easier to work on than I anticipated.

Skid plate was held on by 4 bolts.

Driveshaft had 8 bolts and for awhile I thought the crossmember would need to be dropped. Ended up getting it out by compressing the shaft, then sliding it up and over the front diff and back down between the downpipe and crossmember. Hopefully it goes back easy!

Anything special needed when I put the new switch in? Looks like all that is needed will be to screw it in, is this right?

Gonna get at it again in the morning.

[lapoltba]

When I replaced the switch on my T4, the new one came with sealing compound on it already.  There is a torque spec for it, which you can find somewhere in the Eaglepedia.  I didn't and just tightened it "enough" so it was tight but didn't risk stripping the case.

FYI, the car will run if the switch is bad/disconnected.  The P.O. of my car had obviously run over something that jammed it's way over the crossmember and bashed up the vacuum shifter, and the NSS.  It was completely disconnected.

[BenM]

It's only 24 ft-lbs.

[Zoro]

Got it installed today, turns out you need a 1" deep well socket.

On the OEM unit there is an indent on either side of the 3 prongs. The replacement does NOT have the indentation. The connector is on there but not the best fit. I think I need to pull the connector back off and Dremmel out the tab on the connector to get it to seat better.