[Mk2] [Turbo] Air con removed..radiator fans on constantly

Anything to do with the electrics of the car.

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rossonza
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[Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

As above. My radiator fans are on 24/7. Believe this is to do with removing the Aircon.

Is this the pressure switch I have to bridge?
Image

Also I've got this near my radiator on both sides it looks like. Connected to nothing. Any ideas?
Image

Thanks
Ross
:thumleft:
pbmr2
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

real easy fix.

Either leave the sensor on the loom in the frunk or bridge the 2 pins with some wire.

you don't have to bridge the sensor, it's the plug on the loom that needs bridging. The non AC cars have a tiny plug that does this bridging but 2 spade connectors and a bit of wire works just as well.

On my car for the moment I just took the sensor out of the pipe (I've fully removed all parts of the AC system) and left the sensor on the loom plug. I intend to bridge the pins as a lasting fix.


The plugs.. is the one on the right the sensor for the bonnet latch? the other one looks like the plug for the temp sensor in the rad.
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

pbmr2 wrote:real easy fix.

Either leave the sensor on the loom in the frunk or bridge the 2 pins with some wire.

you don't have to bridge the sensor, it's the plug on the loom that needs bridging. The non AC cars have a tiny plug that does this bridging but 2 spade connectors and a bit of wire works just as well.

On my car for the moment I just took the sensor out of the pipe (I've fully removed all parts of the AC system) and left the sensor on the loom plug. I intend to bridge the pins as a lasting fix.


The plugs.. is the one on the right the sensor for the bonnet latch? the other one looks like the plug for the temp sensor in the rad.


So in the first picture i need to bridge the connector thats on the loom?

my new radiator doesnt have a temp sensor port. presume thats not going to help things.
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

bump... its one of those niggles i want to fix before its first mot. any help would be appreciated. :thumleft:
pbmr2
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

rossonza wrote:
pbmr2 wrote:real easy fix.

Either leave the sensor on the loom in the frunk or bridge the 2 pins with some wire.

you don't have to bridge the sensor, it's the plug on the loom that needs bridging. The non AC cars have a tiny plug that does this bridging but 2 spade connectors and a bit of wire works just as well.

On my car for the moment I just took the sensor out of the pipe (I've fully removed all parts of the AC system) and left the sensor on the loom plug. I intend to bridge the pins as a lasting fix.


The plugs.. is the one on the right the sensor for the bonnet latch? the other one looks like the plug for the temp sensor in the rad.


So in the first picture i need to bridge the connector thats on the loom?

my new radiator doesnt have a temp sensor port. presume thats not going to help things.


yes, just bridge the 2 pins in the plug, in frunk. you could even take the plug off the loom and solder the 2 wires together, but that can't be undone as easily. Make sure it works before doing the more permanent 'fix'

the sensor can be removed from the ac pipework, that can be put into the plug, which would mean you don't need a bridge.
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

i bridged that connector shown in the picture with a paperclip and it made no difference to the fans running or not. I'll try it again tonight see if it was just bad luck/placement on my behalf.

:thumleft:
markstevieandmads
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by markstevieandmads »

Or you can do what i done and just fit a switch so if your on track or stuck in traffic you can manually override the fans to put them on
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

markstevieandmads wrote:Or you can do what i done and just fit a switch so if your on track or stuck in traffic you can manually override the fans to put them on


id rather have it automatically cool the engine as it will be a street car. i wouldn't trust myself to remember to turn the fans on.. but worst case its definitely an option.
markstevieandmads
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by markstevieandmads »

rossonza wrote:
markstevieandmads wrote:Or you can do what i done and just fit a switch so if your on track or stuck in traffic you can manually override the fans to put them on


id rather have it automatically cool the engine as it will be a street car. i wouldn't trust myself to remember to turn the fans on.. but worst case its definitely an option.


It still works automatically. All you are doing is breaking the link circuit to bypass it and turn the fans on. In theory u dont need it as it should come on when needed but i was running cables and had a spare switch not doing anything on my switch panel.
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

oh i didnt realise. very interesting.... do you have info on how you installed the switch wiring etc? :thumleft:
markstevieandmads
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by markstevieandmads »

Very simple. You would normally put a link in that connector to short it so all you do is run a cable to each side of the connector to a one way switch. That way the switch is shorting and unshorting the link which in turn turns the fans on and off.
Like i said, if your coolant system is running ok then you shouldnt really need it but its just handy to have if you find your car is suddenly getting too hot you can just flip the switch and possible save your headgasket.
I was already running cables and already had a spare switch mounted so it was an extra minute for me to do it.
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

markstevieandmads wrote:Very simple. You would normally put a link in that connector to short it so all you do is run a cable to each side of the connector to a one way switch. That way the switch is shorting and unshorting the link which in turn turns the fans on and off.
Like i said, if your coolant system is running ok then you shouldnt really need it but its just handy to have if you find your car is suddenly getting too hot you can just flip the switch and possible save your headgasket.
I was already running cables and already had a spare switch mounted so it was an extra minute for me to do it.


right, so my 2nd picture, remove the wires from the connector, then just extend the wiring to a switch on my dash.. is it really that simple?
markstevieandmads
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by markstevieandmads »

rossonza wrote:
markstevieandmads wrote:Very simple. You would normally put a link in that connector to short it so all you do is run a cable to each side of the connector to a one way switch. That way the switch is shorting and unshorting the link which in turn turns the fans on and off.
Like i said, if your coolant system is running ok then you shouldnt really need it but its just handy to have if you find your car is suddenly getting too hot you can just flip the switch and possible save your headgasket.
I was already running cables and already had a spare switch mounted so it was an extra minute for me to do it.


right, so my 2nd picture, remove the wires from the connector, then just extend the wiring to a switch on my dash.. is it really that simple?


Yep
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

ok awesome thanks dude, i'll get a switch purchased and give it a go :thumleft:
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

well i bridged the connector, and the fans stayed on still. so back to square one. i need to take a proper look at whats going on.
pbmr2
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

this exact fix worked on my rev2 and rev4 cars.

have you tried plugging the sensor into the plug?

the other lose plugs you found, one of them wasn't for the rad temp sensor was it?
rossonza
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by rossonza »

pbmr2 wrote:this exact fix worked on my rev2 and rev4 cars.

have you tried plugging the sensor into the plug?

the other lose plugs you found, one of them wasn't for the rad temp sensor was it?


my rad temp sensors plugged in to the rad, the only loose connector ive got around the rad is the horn wiring, which i cant find the cable that plugs into it.

if i leave the plug in the sensor on the AC pipework in the frunk it makes no difference. Im sure ive missed something really simple somewhere. this is doing my nut in ](*,)
pbmr2
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

there must be another trigger, as it's the sensor in the frunk, not being there that sets the system off with all fans blowing.

I'm just trying to think what else might cause this.. I'll have a poke at the diagram for you.
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

you don't have the AC turned on in the car do you?
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Re: [Mk2] [Turbo] Air con removed..radiator fans on constantly

Post by pbmr2 »

here is the entire fan setup. the first diagram joins the 2nd from the right.

Image

Image
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