I've been trying to diagnose my lack of reverse lights. 98 Discovery 1 Automatic. 68k.

The lights work intermittently, and I've not been able to find any pattern/reason as to when/why they work. (Though it seems that they will work every morning, or if I've left the car alone for a period of time; they work much less often after the car has been driven; Might be fooling myself...)

Fuse 14 is good (instruments work; they're on the same fuse?); the bulbs are good; the two grounds are clean/good.

I did check pin connector 105; no power to pin 3.

Seems like it may be the inhibitor switch -- RAVE says that the reverse lights are integral to the swtich, but if that was bad would I also be having problems with it not wanting to start (inhibit)? I don't have that problem, just the reverse lights.

The nut in my shifter handle was loose, and I thought tightening it up might tighten the shifter cable (which I read here can get stretched?), which might impact how the contact/plunger on the inhibit switch is operated, etc. But no difference.

Is the switch something that can just be cleaned or renewed in any way?

Just looking for any other ideas before I pay the $179+ for a new switch. Thanks for any help. This site is a great resource. I must have spent 10 hours on it in the last 4 days!

 

According to the schematic attached, the two switches are mechanically paired, but electrically separate, so you are not having starting issues, while some other fellow has great reverse lights but can't start. Maybe salvage yard (DIY) or a parts guy or fleabay? If you can get at the switch, a few shots of contact cleaner spray may revitalize it.

 

Good point; I should have caught that.

The connector is a bear to get at, but I'm going to try and hit it with some electrical contract spray and report back. Thanks for the help.

 

here's pix -

 

Since it appears to be heat related I'd check to make sure it hasn't backed out some and that the pins in the plug are in good shape and are a nug fit.

 

Thanks again for the help/advice. I finally got under the truck and checked things out.

It does not appear to be electrical.

I pulled the inhibit switch out and cleaned the electrical connections on the plug. Reconnected the plug. With vehicle in reverse I manually pushed the plunger on the end of the inhibit switch and the reverse lights work. Reinstalled the inhibit switch, and reverse lights do not work.

Would it make any sense that the selector cable is the issue? If it is somehow misaligned would that cause the operating lever to not extend as far it is should? Seems like the end of the lever that is inside the case (and pushes on the plunger of the switch, operating the lights) might not be travelling far enough, and not pushing the plunger enough to make the electrical connection

I'm checking RAVE to see if the cable is adjustable -- looks like it is at the adjuster, though mine is rusty and soaking in PB right now. Is it also adjustable via the nut in the shifter handle?

Any other thoughts?

Thanks again.