1995 Land Rover Discovery with the 3.9L and a distributor cap. 121k miles. No sunroofs which is new for me. I'm beginning the process of nursing this baby back to good health.

The following things don't work, are they all tied together in some way that I don't know about?

1. Cruise doesn't work. Bought new bellows to replace rotted one, checked the lines for leaks, didn't find any. Checked brake pedal switch, the tube was off the switch. Still doesn't work.

2. None of the switches on the dash and console work or light up when you press them. Cruise, rear windshield wiper, the weird light switches, recirculate air, AC etc. I read somewhere that the rear light bulbs can affect that and I replaced a burned out one in the bumper, but still the same. The 1, 2, 3, 4 fan speed control still works, thank goodness. The clock kinda works, you can tell it is getting power. Speedo and gauges still work.

3. SRS and Anti Lock lights are on on dash.

I've checked the relevant fuses the best I could and don't see that they are burned out. Is there some master fuse or tie in point that all of this stuff is going through? Or do I have many multiple problems haha?


Different problem- a lot of the time while driving the headlights vary in intensity and so do the dash lights, they kind of just pulse. The red battery light also flashes off and on sometimes with the same pulse. If I put a voltmeter on the battery while it is doing this, the voltage jumps around 14.2, 13.7, 13.2, 14.1 etc. The previous owner said he just replaced the alternator but then he let it sit for like half a year at his work's parking lot with the passenger window messed up and down and dust blew in coating the interior of the Disco lol. That is how long it sat. Do I need new brushes or is it the voltage regulator do you think? I can tell the rear of the alternator has been messed with as the nuts look like they have been tightened too tight and it is kind of mashing the black plastic. I tried to get further clarification about if he got a reman or new or used alternator but the previous owner is now unresponsive to email. I sprayed the alternator with electric contact cleaner while it was running to try and clean out any crap built up but it didn't change the problem. All the connections to battery and alternator are tight also.

Thanks for any help! Glad to be driving a Land Rover again, they are my favorite car, this is my third one and I keep coming back to them.

 

I'd say you have some ground issues first and foremost. The lights/ect seem to have a common fault. If it was that dusty I'd start by pulling and cleaning all the switches. Then get a wiring diagram from the RAVE. Find the commonality between all those failing parts. Most likely a ground or bad relay issue.

 

First and foremost check your battery connections and ground. You've probably already done that. Also, double-check that the alternator belt is routed right. I've written this before, others have suffered from this: the L/R is the only vehicle I know of where the serpentine belt can be routed incorrectly and 'look' acceptable but NOT have quite enough tension to operate w/o slipping. The dead give-away is when the previous owner replaced the alternator. He probably put the belt on like it would intuitively go which 90% of the time is incorrect. Google the routing and you'll find it.

Mine was put on incorrectly and the P/O and a bunch of people banged their heads around the cluster, computer, looking for all sort of electronic problems till I bought it cheap and figured out the Alt pulley was slipping on the belt. It took me a while though, and tracing down a bunch of dead end theories. The whole cluster would flicker and freak out like it was possessed, headlights bright/dim. Drive around town to get home and everything was good. Only acts up at road speed. That's why it's so hard to figure out. Why L/R didn't put a pulley routing drawing on the header panel, I don't know. Also, check the alt pulley for glazing because if it was rerouted, the pulley is probably glazed and belt needs to be replaced too. That would be an easy fix if that's all it is.

Finally, the alternators are fairly easy to rebuild. You can buy a whole rear brush kit for them on the internet. Don't ask me where ...it's been quite a while since I did mine.

Good luck, take care,

Let us know what it turns out to be.

Mark G

 

The Cruise Control ECU is probably toast. You can open it up, try to pinpoint the problem, and resolder it. Or you can buy a D2 CC ECU and pigtail from Paul Grant and splice it in. Also try taking the switch out and cleaning it.

 

Before you go ripping into the electricals to find the cruise ECU, try rejuvenating the switch with de-oxit and contact cleaner. Sometimes it is just a matter of ridding the contacts of corrosion.

Belt routing should be one of your first checks...

 

Yep I just went out and checked from work out in the cold. The previous owner has the belt routing messed up. Wow. He bought this from an estate sale and did one thing, he told me. Replaced the alternator. And he screwed that up. Instead of going below the water pump pulley he has it going off to the side of it and around.

Thank you immensely for posting that routing diagram!

I can't wait to get that fixed. Like you said it happened at highway speeds only mainly which made it really a head scratcher since usually when my alternators have gone out they work best at high speed.

 

Does anyone have any insight into problem #2 I listed above in the original post? I've done more work on it and I am stumped. I have 12v at the switches but they won't light up or do anything. I refused to believe that every single switch had gone bad but I took one apart and noticed green corrosion on the contacts so I bought salvage switches that were guaranteed to not be bad and replaced the AC, recirc, and cruise switches. But the problem remains the same. I've tried looking in the RAVE manuals but I don't see anything like this problem. All the troubleshooting seems to be for downstream things. I can't even get the freaking indicator lights on the switches to come on.

Everything behind the dash looks like factory, no indication that someone did anything weird.

 

Regarding those switches, I had to replace the bulb in every one of them.

 

How do you replace the bulb in them?

 

They are T3 Neo Wedge type bulbs. Ebay. I used leds, green, white, orange depending on the switch. Some of the switches use two. They come out of the hole with a quarter turn. The polarity matters, turn the bulb 180 deg if it doesn't light. The thin wire contacts are fragile, you may have to bend them slightly to get good contact with the switch contact surfaces. This will all make sense when you get there.