Location of Scavenger fan sensor please.

[mikelamb]

Hi All,

I'm trying to check that My scavenger fan is working but I'm not sure which sensor to remove by the handbrake.
I have disconnected one which puts the handbrake light out, another which puts the seatbelt light out, but still no fan coming on!
I would be greatfull if someone could point Me in the right direction.

Mike.

[stilldesperate]

Hi Mike,

From memory, you need to short the two wires together on the sensor, by the handbrake. I made a button on a spare switch blank to press if stuck in traffic to get some air over the engine. I'll try to have a look tomorrow to let you know.

SD

[mikelamb]

Thanks SD for your help mate. Much appreciated.

[stilldesperate]

This is the sensor



It's not simply a case of connecting across the two wires.

This is from memory. Disconnect the plug from the sensor (A blue and a yellow wire?) (It needs "pinching" to release it), Then start the engine. I used a metal paper clip to momentarily connect across the plug, and you hear the fan running. If you stop the engine, the fan stays on for a few minutes.

Sorry this isn't too technical, if you don't get the results I describe, let me know, and I'll do some more accurate checks on mine to make sure of the sequence.

Hope this helps

SD

[olebrock]

On my 2.0 petrol I just disconnected the plug and started the engine, fan came on without needed to bridge the contacts.
There seems to be many variant Bongo Beasts
best regards,

[jaylee]

SD, did you use a latching switch to bypass the scav sensor?
Or a non latching switch to momentarily trigger, causing the fan to operate for its own set timing?

[apole]

On my V6 petrol, from memory disconnecting didn't do anything but momentarily bridging the contacts did. The fan then cut off when I turned the ignition off. Didn't realise it had a timer.

Andy

[jaylee]

I found the disconnection of the scav sensor didn't turn the fan like the the one on the drivers side of the engine kicked in the rad fan...

I found a slight currant coming off the scav wire, (5 volts?) but didn't bridge to check for fear of shorting out the ECU thingy?

I know my rad fans are OK, but i'm not convinced about the scav fan angled front of the block?

[dandywarhol]

Mine's been working away just fine here in hot, hot Spain. But only when we've stopped and the engine bay heat soak triggers the fan sensor. No need for messing about with auxiliarry switches IMO - the Factory techs know their stuff..............

[mikexgough]

My scavenger worked just fine once again today......

[stilldesperate]

SD, did you use a latching switch to bypass the scav sensor?
Or a non latching switch to momentarily trigger, causing the fan to operate for its own set timing?

Use a momentary switch, Jaylee.

(If you hold the button in, the glow plug [or some other] light comes on on the dash!)

SD

[jaylee]

SD, did you use a latching switch to bypass the scav sensor?
Or a non latching switch to momentarily trigger, causing the fan to operate for its own set timing?

Use a momentary switch, Jaylee.

(If you hold the button in, the glow plug [or some other] light comes on on the dash!)

SD

Cheers SD, what i thought..
Though today i actually heard it come on without the rad fans.
The rad fans blow against the the radiator & make more of a noise due to the air hitting the rad surface at close proximity.
The scav is quieter in the respect of the acoustics of where it's positioned.

I'm still in two minds about fitting an override.. I fancy it might help on the long climb!

[dandywarhol]

I've never been aware of the scavenger fan coming on when the vehicle is moving, only when stopped for a few minutes in 35+ deg. ambient temp. and often independantly of the radiator fans.
If I remember correctly the fan sensor needs something like 180 deg C air temp in the engine bay to switch in and it is only a millisecond trigger to the ECU from the sender. Thats probably why the dashboard light comes on. I've said it before but I'd be very wary of sending spurious signals to the ECU - the scavenger fan works just fine when the demand is made on it.