Back again, hopefully some Rover Guru out there will have some solutions about this problem.
My 98 Disco will only start if the back tailgate is open. If I push in the light switch tab, it wil NOT start, it only makes a clicking noise by the glovebox.
The interior lights come on when the button is released and goes out after several seconds when the button is pushed in.
I have cleaned every connector that I can find with no change.
Anyone have any ideas?

 

I'm sorry that you started a Part II. What a PITA you're dealing with.. good luck.

 

My guess you have an alarm issue, do you have a factory remote? The green alarm box is behind the glove box

 

When I bought it, it did not have a remote only a ignition key.

 

Oh, wonder if that's the problem, tried lock and unlock from drivers door with key ? I know there are threads here with similar issues

Clean your battery terminals and all grounds just for good measure

 

there was a thread on discoweb about this exact issue. i can't remember the name of the thread but it might be worth asking over there in the tech section.

 

I'd use the ETM to trace every step of the ignition. You're bound to find the trouble spot.

 

I checked everything I could get my hands on, cleaned grounds, starter wires, reseated all connectons with No change.
The problem: It would NOT start, it would only click at the right side relays by the glove box.
Found: When the tailgate was open it would start. If you pushed the door (light) switch in, the RPM increased about 200 RPM. If you tried to start it with the switch in it would not start.
The fix: Disconnected the switch and grounded the purple/white wire. It will now start. GO FIGURE ?????
It makes NO sense at all, BUT it works.
I have been driving it for the last week with no issues.

 

The thread on Dweb was titled "Best Tech Thread EVER" and was started by Dan Chapman several years ago. He had the same issue with the tailgate. It's an interesting read.

 

See page 336 of 591 in the ETL for a 97 (later vin) . There is a diode that couples the timer module (MFU) and the alarm to the same point for that door switch. Could be bad diode or bad MFU.