Reverse Light Switch Location - A/T

[brentlehr]

Where's the reverse light switch on a 89 A/T van?

[timsrv]

It's built into the Neutral safety switch on the PS side of the transmission.

[brentlehr]

ok. my reverse lights are not working and haven't been in the 3+ years I've owned the van. Bulbs are good. Does that mean I have to replace the entire neutral safety switch?... a quick search seems like that's pretty pricey.

[timsrv]

I assume you already checked the easy & most likely items? Normally the fuse would be 1st, but the B/U lights are powered by the 7.5A gauge fuse (top center of your fuse box). So it's probably safe to assume this fuse is good (otherwise your gauges wouldn't be working). The next most likely trouble spot is the bulbs & the sockets (yes, you can actually have 2 bulbs burned out at the same time :dizzy:). Also make sure the bulbs belong here. Sometimes you will find "double bump" bulbs inside of "single bump" sockets & visa versa :doh:.

The next thing to check is the neutral safety switch. There are 4 wires that come out of the switch. The ones you'll want to check are the 2 inside the small round plug. You can unplug the connector & use an ohm meter to check continuity but I like to check the system under load (sometimes you can have continuity but still have a bad switch). For the continuity check, simply unplug the small round connector & use an ohm meter between the two conductors inside. With the shifter in park there should be no continuity. Now chalk the wheels, set the parking brake, and shift the van into reverse (for safety reasons the van should NOT be running). Now you should have continuity. If you don't, then the neutral safety switch is bad. If you do, then it still could be bad.

If the continuity test was inconclusive, then leave the safety switch disconnected & put the ignition switch in the "run" position (don't try to start). Verify the shifter is still in "R" & use a test light on the red/blue wire going to the safety switch. There should be power here. Now plug the safety switch harness back in & check for power here again. If power goes away then your problem is a bad connection somewhere in the supply line to the safety switch. If there is power then use your test light on the red/black wire. If there's no power then the safety switch is bad. If there is power then the problem is somewhere between the safety switch & the B/U lights. Use the test light on the wire going into the bulb sockets. If there's power here then you have a bad socket or a bad ground (assuming of course there's a good bulb of the correct style installed). Good luck. Tim

[brentlehr]

Awesome. Thanks for the detailed troubleshooting. I've already checked all the easy stuff so I'll see what this turns up.

[brentlehr]

Revisiting this. I'm finally getting around to replacing my neutral safety switch. Below is what the service manual says adjusting. What does 'neutral basic line' refer to?

ADJUSTMENT OF NEUTRAL START SWITCH
If the engine will start with the shift selector in any range
other than "N" or "P", adjustment is required.


1. LOOSEN NEUTRAL START SWITCH BOLT AND SET
SHIFT SELECTOR IN "N" RANGE


2. ADJUST NEUTRAL START SWITCH
(a) Align the groove and neutral basic line.
(b) Hold in position and tighten the bolt.


3. TORQUE NEUTRAL START SWITCH BOLT
Torque: 55 kg-cm (48 in.-Ib, 5.4 N·m)