Landcruiser Electric Clutch Driven Water Pump

[bartholdy]

Landcruiser Colorado 3 litre D4D common rail turbo year 2000

I have the above vehicle and the heater has never raised the cab temperature as well as our old 1996 Prado.

I have noticed the engine is fitted with a secondary water pump which is plumbed into the pipe feeding the heater matrix. It is driven, along with the air con pump etc. from the multi grooved belt. It is fitted with an electric clutch (which works) very similar to the air con pump. It is positioned high up on the left hand side as you face the engine (directly above the air con pump).

I have never seen it with the clutch engaged so I rigged up a feed to the clutch, so that the pump was running, and this did seem to improve the heating, although the difference was not dramatic.

I can find nothing about this pump in the manuals, or on the internet. The 12 volt feed comes from a single core cable which disappears into the wiring loom. I have checked all the fuses and searched for any controls that might be relevant but it still does not work. I appear to have lost the run signal. The vehicle has been totally trouble free over the last five years and has no electrical problems.

Can anyone throw any light on this (to me) mystery?

[marlot]

I wonder if it is something to do with the power heat (mode where the car is set to warm up more quickly). I have a power heat button on my 120-series. It raises the revs, seems to alter the fueling and gets the car up to temp quickly

[ormi]

the man above is correct...youll have a switch that you manually switch on/off

[hedleyf]

It may not always run depending on the engine temp, switch the power heat switch on first thing in the morning and you should see it spin ,may cut out after a while as the engine temp raises but can cut back in as the temp drops ie idling in traffic.