9060davidj wrote:hi to all
tested the cooling fan by using a battery charger connected the live from the battery charger to the brown cable and then the earth to the red on the pcb and the high speed worked then the earth to the grey on the pcb nothing so then i tried a cooling fan that i knew worked and i had low and high speed so the resistor has failed i will send for one and try again
david
Hi David.
replacing the silver resistor with a gold one should have your fan working again.
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I have a few if you have paypal.
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The R75 and or the MGZT 1.8, 2.0, or diesel sometimes have a two wire 2 speed fan which fails, most of the time it will be the silver resistor that as failed once failed it will need changing for a Gold resistor.
This thread/post will hopefully help those whom wish to deal with this replacement themselves.
Once you have purchased the Gold resistor you will need to remove the front bumper to carry out this task, there are several threads on how to remove the front bumper please use one of those to help you remove the front bumper.
First job is to check that you have a silver resistor in place on your R75/MGZT do this by looking through the front grill at about 2.0 Oclock Fig1
1
Once you have established you have a two wire 2 speed fan with silver resistor remove the front bumper Fig 2
2
Now you have the front bumper removed unplug the fan from the car loom as the fan is permanent live on a diesel Fig 3
3
Your nest step is to remove the crash bar 4 bolts and 1 nut each side 13mm Fig 4/5/6
4
5
6
Once you have all bolts and nuts removed take off the crash bar Fig 7
7
Lie the crash bar to one side out of the way Fig 8
8
The main reason for removing the crash bar is that is will give you more access to remove the silver resistor and fit the gold one, working through the largest gap in the fan blade Fig 9
9
Remove the two screws holding the fixing plate to the fan for the silver resistor Fig10
10
10a
With the two screws removed pull the silver resistor through the fan blade Fig 11
11
Now you have the silver resistor through the fan blade cut the black wire as close to the resistor end as you can, giving your self a good length of wire Fig 12/13
12
13
You now need to strip back the wire ready for soldering or crimping the gold resistor to Fig 14
14
Hopefully you have wired the gold resistor already with a small tail to aid the fitting to the fan black wire, or you have purchased a gold resistor already fitted with the tail, you need to push these together weather you are soldering or crimping. Fig 15
15
The gold resistor I use at the meets or on members cars already have the wire tail fitted before and crimped so all I have to do is crimp the joint to the fan wire Fig 16
16
Make sure your crimping is good and tight and remembering to add a length of heat shrink onto the wire before crimping Fig 17
17
Once you are satisfied with your crimp or soldering heat shrink the joint Fig18
18
Repeat this procedure for the other wire on the fan again making sure heat shrink is added before you crimp or solder Fig 19
19
Feed the gold resistor and wiring back through the fan blade fit the resistor to the fan using the screws you removed earlier, and cable tie the wiring to the fan supports to stop the wire from touching the condenser and fowling the fan blades when it is running. Fig 20
20
Now you need to test the fan refit the loom plugs in the wheel arch, if you are working on a diesel car ignition to II with all A/C off press the demist button, on a petrol car you will need the engine running, the fan should run continually switch off the demist button and retest a few times before refitting the crash bar and bumper, you have now completed fitting a gold resistor.
Cheers Arctic
