Auto trans temp switch RR vs D2TD5

[rjhjstr]

Hi all
Well I fried my D2 TD5 auto transmission when towing our caravan up near Coober Pedy. Had to get back to Adelaide where the boys at Triumph Rover Spares did a good job and swapped the auto box and transfer box with units from a wrecked late model (2005) D2. In the process they also changed the auto trans cooler for one out of an HSE Rangie. This has approx 60% greater cooling capacity so hopefully the problem won't re-occur. However when we came to connect the over temp switch from the RR cooler it brought the dash warning light on immediately. It's obviously different from the type originally fitted to the D2. Question is how different and can it be made to function with the electrics in the Disco. My Rave CD doesn't cover the RR but the Disco version indicates that the over temp switch simply connects to earth when activated and brings on the dash lamp. How does the HSE RR version function?

Russell

[ladas]

Don't know if this helps at all - but on the D2 there are two sensors, one on the box and another on the cooler.

On the D2 - the power flows from the fuse through the warning light then to the switch, which as you say is grounded when the temp rises.

The RR whilst slightly different - I think it mounts externally - but it still switches to earth - some models it earths the small cooling fan they fitted for the cooler.

My guess it would be the sensor is faulty.

Disconnect the wire on the temp switch at the cooler - and when the engine is cold - check the resistance across the terminals on the cooler. It should be open circuit, if it's not then the switch is faulty.

[rjhjstr]

Thanks for input Ladas. The sensor seems to be closed i.e. zero resistance at ambient temp. Assuming that it's just a simple switch and nothing unusual like a thermocouple or thermistor then it seems like a simple case of a faulty switch which will have to be replaced. Can the switch be removed and leave the vehicle driveable? Obviously in the D2 if you remove the switch then the ATF will pour out. Does the same happen with the switch on the RR cooler?

Russell

[ladas]

Thanks for input Ladas. The sensor seems to be closed i.e. zero resistance at ambient temp. Assuming that it's just a simple switch and nothing unusual like a thermocouple or thermistor then it seems like a simple case of a faulty switch which will have to be replaced. Can the switch be removed and leave the vehicle driveable? Obviously in the D2 if you remove the switch then the ATF will pour out. Does the same happen with the switch on the RR cooler?

Russell

Now I haven't physically seen/handled a switch off a RR, but looking at all the diagrams it looks like it's externally mounted - sensing the temp from the external wall of the cooler - it does not look like it 'intrudes' into the fluid/cooler itself.

From reading about it - it would appear to be a simple switch - with a pre-determined switch point.

If it was a thermistor you would still have some 'resistance' reading at ambient - unless you were so unlucky to get the exact temp as for the thermistor to measure 0. bloody unlikely - but the way to check is re-test it when the engine is warm/normal temp - if it's still 0 - then the switch is buggered - but I think we already know that

I'll have another check on the diagrams/drawings to see if I can spot anything more about being surface mount.

[ladas]

Every picture I look at - makes it look like a surface mount.

See link - page 10

http://www.xks.com/landRover/catalog/pdf/LandRoverCat96_133V4_1.pdf

[ladas]

I think the part no. of the switch is ESR4329

[PhilipA]

Why pull it out. Why not just disconnect the wires so they are open circuit?
Regards Philip A

[justinc]

Just had Phil at TR spares get one of my customers out of trouble while touring, very quick, very knowledgeble, and excellent service. They are definately a god send especially smack in the 'middle' of the country.
The HSE cooler conversion is a must for the Tdi D1's also, I have done one recently and it was easy on the D1. Stops you worrying about oil temps anymore. The best way to travel in a D2 while towing is in 3rd gear, it will lock up the converter at about 70 to 80k and reduce heat hugely.

JC

[rjhjstr]

The obvious answer to Philip A is that having fried one transmission, and as a result having had to abandon the trip to Darwin, I'm paranoid about doing it again. The idea of running without an over temp warning lamp does not appeal.

Russell

[ladas]

Did you re-check the resistance at warm/normal temps ?

[goldey]

Gents

Just resurrecting an old thread as a search revealed somebody else having had similar troubles to myself.

Just wondering whether there was an outcome of the operation of the surface mount temperature "switch"? My hope is it works like a normally open, then reaches its preset temp and closes to make the lamp on the dash light up. If it is a varistor, then I'll have some more work to do and that goes against my laziness grain........;)

Cheers
Goldey

[PhilipA]

Its probably no help but in a RRC and probably D1 it is a simple on /off.
Mine came on after a 70CM water crossing, so I pulled the wires ( after burning my arm reaching down between the rad and motor to dry the terminals.)
This didn't fix it, so I left the wires pulled. I tested it again once home and Lo and behold no resistance.
Now does anyone know if the RRC switch ( which is in the cooler line behind the LH side of the Rad) is dry or wet.
Seeing it is working OK now I will leave sleeping dogs, but you never know.
regards Philip A

[Hamish71]

Guys, I have fitted the RRC oil cooler to my D2A, and have the same problem. My Trans oil temp light is on. I know its an external temp sender, and have no issues with removing/replacing it....but it should work fine just connecting it straight into the existing harness, shouldnt it? If so, then I probably have a faulty sender and will replace it with a new one.

Thanks in advance.