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Old 26th July 2021, 14:59   #1
spongeh
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Default Radiator fan identification

I think I've got the wrong fan motor fitted to my car.

I've just purchased a 2002 ZT-T 180 KV6 Auto and the radiator fan doesn't work at all. I stripped the car down yesterday, expecting to find a 3 speed fan (no resistor visible through grill) and have to replace the brushes in the motor, but they were perfect and the fan tested fine when on the bench.

Looking at the motor it had 3 wires going into it, one of which was purple and there was a resistor rivited to the chassis leg and some rather interesting looking wiring.

The control box had 2 relays, one small and one large.

The wires back to where the connector connects to the loom had 2 control wires and a pin missing from the connector, but the loom side connector had 3 control wires.
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Old 26th July 2021, 15:15   #2
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I believe 2002 would have been roughly the cut off point for the 3 speed fans, but there's no certain point that I know of.

If it has a resistor then it's a two speed fan, but mounted on the chassis leg is a new one, normally the resistor is mounted on the shroud.

All harnesses will have wiring for a 3rd speed in place and the fact that your two speed fan doesn't have a pin is I believe perfectly normal as it doesn't require that connection.

Two relays is again normal, but why the fan works on the bench but not on the car is nothing I can answer. I usually check fans on the bench too, but use Toaf for real confirmation.

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Old 26th July 2021, 15:30   #3
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I bought a brand new fan that would not work.
Duncan very kindly applied his T4 at the nano and made a forced working which showed it was working but not by the car on demist etc.
After lots of head scratching the relays were checked and working. You could hear the click. That ruled out the relays.
Arctic suggested looking inside the control box and sure enough the board was not correct for my car.
Luckily I had already given him my old fan so we swapped boards and hey presto it worked.
Dates were a factor I think. The fan had a date 2002 and my car is early 2004 Mk1.

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Old 26th July 2021, 15:31   #4
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Quote:
Originally Posted by vitesse View Post
I believe 2002 would have been roughly the cut off point for the 3 speed fans, but there's no certain point that I know of.

If it has a resistor then it's a two speed fan, but mounted on the chassis leg is a new one, normally the resistor is mounted on the shroud.

All harnesses will have wiring for a 3rd speed in place and the fact that your two speed fan doesn't have a pin is I believe perfectly normal as it doesn't require that connection.

Two relays is again normal, but why the fan works on the bench but not on the car is nothing I can answer. I usually check fans on the bench too, but use Toaf for real confirmation.

Regards
Never thought of Fan control in TOAF ... just plugged it all in and the High Speed works when I click the start in TOAF.

Medium and Low do nothing, I assume this is the resistor as the old one was showing an open circuit and I've ordered a gold 100w .50ohm resistor to replace it with.

I was just worried that I was working on the fan for no reason if it wasn't correct.
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Old 26th July 2021, 15:49   #5
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All relatively good then, fix the resistor and test again. Just remember that although you can test all three speeds with Toaf, you don't actually have more than two speeds in reality.

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Old 26th July 2021, 21:52   #6
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What does it say on the control box ? it sounds like you have a 1.8 fan on your car, three wire 2 speed fan with resistor, as opposed to a two wire 2 speed fan which are mostly on 2.0 & 2.5 petrol cars, also four wire 3 speed fans.


petrol two wire 2 speed fan control box.
1

K1.8 control box.
2

The above side by side.
3

4
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Old 27th July 2021, 09:58   #7
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Quote:
Originally Posted by Arctic View Post
What does it say on the control box ? it sounds like you have a 1.8 fan on your car ...


Arctic's spot-on, as usual.

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Old 27th July 2021, 10:01   #8
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Quote:
Originally Posted by vitesse View Post
I believe 2002 would have been roughly the cut off point for the 3 speed fans, but there's no certain point that I know of.
Hi Mike,

i have a note that an MGR technical bulletin gives it as VIN 328241 but I wouldn't take that too literally.

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Old 27th July 2021, 22:57   #9
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Quote:
Originally Posted by Arctic View Post
it sounds like you have a 1.8 fan on your car, three wire 2 speed fan with resistor, as opposed to a two wire 2 speed fan which are mostly on 2.0 & 2.5 petrol cars, also four wire 3 speed fans.
My 2004 1.8 has a 2-wire, 2-speed with resistor. The earlier 1.8s had 3-wire, 2-speed, non-resistor system, surely?


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Old 27th July 2021, 23:37   #10
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Quote:
Quote:
Originally Posted by T-Cut View Post
My 2004 1.8 has a 2-wire, 2-speed with resistor. The earlier 1.8s had 3-wire, 2-speed, non-resistor system, surely?


TC
Hi TC
yes you are correct

1

2

3

But it does seem he as a 1.8 three wire fan on his car which may have been messed with, photos of his fan and wiring would be good.

Wiring control box of 1.8 fan with resistor.
4

Wiring control box 1.8 fan three wire 2 speed
5
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