Thread: Limp mode in wet weather!

Hi All,
I have been reading your forum with interest for some time now but have not posted, but frustration has got the better of me! I am in the central west of NSW (Mudgee area) and have a disco 2 TD5 auto which has gone beautifully for the first twelve months or so of my ownership (with the exception of a fuel line rub through & a power steer line rub through).
I took it out a couple of months ago on a wet day & went through some water on the road. It went into limp mode, m & s lights flashing 3rd gear only. I brought it home parked it in the shed & when I got back to it a few (dryer) days later it was fine & remained that way for a few weeks. Next sign of trouble was a trip to Armidale a few weeks later. It was again wet & within a few k’s of leaving the shed we were back into limp mode. At this stage I discovered that it only seemed to go into limp if in in D or 3rd rarely, if ever when put into 1st. The D indicator on the dash came in & out a various times during the trip.
On return from this trip I thought the short time between wet road/ weather suggested the water was getting in fairly quickly, therefore probably not the selector aka xyz switch so I opened the connector above it and cleaned it with electrical contact cleaner & blew it out with compressed air, voila off it went no further issue.
In early January I then hooked up the caravan to head up the north coast. It went beautifully for about 300km until just before the New England Range ( & some more wet weather), cleaned out the connector again next morning & it lasted about 10km before going back into limp. Eventually got to destination and cleaned connector out with metho. Went fine for the two weeks we were away including a trip to Grafton ~1hr each way in torrential rain.
Hooked the van up to come home (raining again), got 15km down road & into limp, opened & sprayed the connector with contact cleaner twice on the way home to no avail.
Upon getting home I decided to bite the bullet & got a selector switch ($670!), fitted this with no improvement. Have since had it out to local mechanic who has a code reader, code says selector switch is the problem. I have also read that dodgy battery has caused similar issues for others so cleaned the battery terminals and it behaved again (mechanic said battery tested OK and its given no signs of being dodgy. So following this I took it back to the mechanic, got the gearbox serviced (filter change & oil) and got a new battery. He washed the underside down and road tested the vehicle, went well (weather had dried out as well). It made 60km this time and again went back into limp mode.
I intend to spend some time finding and cleaning earth points and checking the connections in the relevant fuses but have just about run out of ideas beyond that, can any of you guys suggest anything?

Thanks in advance
Phil

Thanks Biggin,
I was perusing Rave and discovered (I think in the electrical library) a brief mention of LandRover using a special grease (part no... etc) on some under body connectors, did not see anything about this when I replaced the wxyz switch. So, I did some research and found that this was probably a dielectric grease aka silicon grease. I aquired some from a friendly telephone linesman (couldn't source any the locally on a sunday and just happened to see him repairing a junction box on the corner a 100 yards from home!) Would like to have also got some conducting grease to put on the pins of the connector but I have separated the connector and syringed the silicon grease onto the mating surface at the bottom of the pins and also around the outer so that it will fill any gaps through which water could enter. Only done 6 k's in a test run but so far so good. Will update this if it works, might help someone else.
Another little gem I picked up as a result was that there are two aircon drain pipes, the one over the wxyz connector and another over the rear uni on the front prop shaft. As a result of getting under the vehicle to chech the connector I noticed the UNI wasn't looking too good. When I ordered an exchange the guy suggested that they fail due to rust caused by the drain dropping onto them. I have consequently siliconed an extension tube into both drains to a point below the level of anything sensitive. Hope this is of use to someone, if the grease doesn't work I will follow up on Biggin's welcome advice.