Engine fan manual switxh

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Dangermike
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Engine fan manual switxh

Post by Dangermike » Wed Jul 08, 2020 12:01 am

Hello,

So just recently bought a 1997 bongo
Very excited,
Have few things to fix, mainly the heater fans,

But my question today is, one of the previous owners installed a switch to turn on the engine fan,
I switched it on today, while playing around and think it turned on the radiator fans,

Why would someone do this?
Also should I turn it on when I ever I start the van or only when the temperature needle gets too high??

If this is off would this affect my aircon not working?
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g8dhe
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Re: Engine fan manual switxh

Post by g8dhe » Wed Jul 08, 2020 8:30 am

I really have a problem with this being done especially if they have disconnected it from the ECU ! If the fans aren't running at the correct temperatures then its better to fix the problem, maybe sensor ? Relying on someone to read a temperature gauge and remember to turn the switch on/off is merely asking for problems :-(
Geoff
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Dangermike
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Re: Engine fan manual switxh

Post by Dangermike » Wed Jul 08, 2020 10:03 am

I agree completely!

Now to find out how to restore the sensor to see if I can get it back to original...
I’m guessing is the on just in front of the radiator by the grill?
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g8dhe
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Re: Engine fan manual switxh

Post by g8dhe » Wed Jul 08, 2020 10:13 am

No its the engine temperature sensor down the drivers side of the engine two wire.
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Dangermike
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Re: Engine fan manual switxh

Post by Dangermike » Wed Jul 08, 2020 11:08 am

Ok thanks,
Will have a look today,
I can see a cable poking out under the seat which may be part of it .

I’m sure I will be back
Rickster
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Re: Engine fan manual switxh

Post by Rickster » Thu Jul 09, 2020 5:07 am

If the fan is to be manually switched, it should have resistors inline with it, the ECU will not like a direct short across it, it thinks there's a fault.
Worst case, it may start flashing the hold light on the dash.
Absolute worst case, all the fans will stay on!
Alternatively, buy a new sensor, if it's original to the van, it may be knackered nowadays.
Engine front fans are usually operated by the ECU, the scavenger can be operated manually without a problem, obviously needing resistors, been there, done that.
Rickster
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Re: Engine fan manual switxh

Post by Rickster » Thu Jul 09, 2020 5:17 am

Just had another thought, is there any service history on the van?
If not, it may be worth changing the coolant valve, maybe that's why someone fitted the switch.
Just a thought.
Dangermike
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Re: Engine fan manual switxh

Post by Dangermike » Fri Jul 10, 2020 3:16 pm

Hi Thanks,

Yes there was a good service history but no mention of coolant valve,

I shall replace that, How hot does the engine need to be for it to automatically come on?
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Re: Engine fan manual switxh

Post by g8dhe » Fri Jul 10, 2020 3:23 pm

What coolant valve ?
The flow of coolant is constant thru the heating matrices front and rear, temperature is controlled on the hot air side with vanes in the air con mixing box.
The flow of coolant thru the radiator is controlled by the thermostat which opens to allow cold coolant into the mainstream into the engine inlet.
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Rickster
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Re: Engine fan manual switxh

Post by Rickster » Sat Jul 11, 2020 7:56 am

I meant the thermostat, must have been half asleep when posting.
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