Cooling Fan Upgrade Resistor Kit

Jules · 20th July 2007, 09:55

Rover 75 MG ZT T Cooling Fan Motor Resistor upgrade Petrol or Diesel models
Improves cooling system reliability and cures "Whooping" Air Conditioning noises
Preserves Compressor life if resistor hasn't been u/s for too long

If no resistor here, older type 3 speed motor is fitted

If resistor here, later type robust fan motor is fitted

Upraded 100 Watt resistor working in situ

Can save 75 ZT owners a garage bill between £300 - £500!
A common fault exists mainly with models after 2003 (not facelift dependant) where you loose the LOW speed function of the cooling fan, due to failure of the under rated poor quality resistor. So this kit has been introduced by ourselves to avoid having to replace the whole motor assembly as the OEM resistor is not available anywhere in the world separately!

Garages simply replace the whole cooling fan motor, control box & radiator cowling costing over £250 for the parts and probably over £200 labour! Main dealer’s diagnostic equipment (T4 Testbook) does not even recognise this problem with a fault code!! And their response to a customers who say their fan is very noisy “Oh they all do that”

Price £26 (Postfree to members here) you can order this kit which comes complete fitting instructions.
Pre-drilled resistor with integral heatsink
Weather proofing heatshrink
Ring terminals
Nuts & bolts
A copyrighted power point presentation on CD
The components supplied in the kit are of higher quality and higher wattage than the original OEM part, giving your cooling system more stability and reliability.

Economy kit price is £14
Undrilled Resistor with basic instructions & terminals.
Cheaper option but takes longer to fit.

Suitable for following models:

All 75 & MG ZT ZTT petrol 1.8, 1.8T 2.0 KV6, 2.5 KV6 or Diesel CDTi and even the ZT 260 V8 4.6

There are 2 types of cooling fan motor: (pics below to identify yours)

Kit required for:
Later type 2 speed 2 wire with silver resistor (viewed through front grille)

Kit not suitable for:
Older type 3 speed 4 wire (no resistor fitted, hence kit will not repair these. Brush wear probable instead)

Symptoms:
Your radiator fan switches on and off quite noisily every 20 to 30 seconds or so with the air conditioning running. Others have described it as sounding like an aircraft taking off!
Normal situation should be constant Low Speed fan operation as long as Aircon is set to On.
NO LOW SPEED function of cooling fan due to the failure of the said resistor. This results in rapid heat build up in the condenser (in front of radiator) hence excessive pressure in the high pressure side of Aircon, which triggers the “trinary” switch. This in turn sends a HIGH SPEED fan signal to ECU. (built in fail safe mode) 10 seconds of high speed fan operation is enough to cool the system down to a safe level again, and so the cycle repeats itself.
All above is assuming the air con is functioning correctly and has sufficient gas

Any other symptoms like no fan rotation at all then this kit will not solve your problem and the motor itself is probably the culprit or relays etc in the control box next to it.

You can tackle the mod yourself or give it to your garage to do as it requires removal of the front bumper assembly and requires some electrical/mechanical knowledge.

Identify if you have a silver looking resistor approx 65mm long by 15mm wide with a black wire coming out of each end just behind the fan blades off to the right as looking from the front (this can be viewed through the front grille and should look like pic below)
Location of resistor (can be viewed through the front grille by moving the fan blades slightly with long implement with ignition off)

If there is no resistor then your car probably has the 3 speed 4 wire/brush motor therefore this mod kit will not cure your fan problem. A new motor would probably be needed as the older type had a shorter life.

Please study the whole CD before fitting.
A fitting service is available but we are situated in North Wales and it will still save you £100’s to travel to get this job kit fitted even if you have to travel :

Enquiries to Tel 07831 457011 You are buying the modification kit in the first picture NOTHING ELSE!

IMPORTANT PLEASE READ!

JMA accept no responsibility for incorrect fitting or bad workmanship or poor fault diagnosis.
This text, CD and photographs are copyrighted by JMA and may not be reproduced.
There is no change to cars performance so no need to inform your insurance company
This will not cure a completely dead fan nor will it repair a non functioning aircon system

Jules · 26th March 2008, 11:55

Bump
Due to recent requests here's the info again!!

20th July 2007, 09:55	#1
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Cooling Fan Upgrade Resistor Kit Rover 75 MG ZT T Cooling Fan Motor Resistor upgrade Petrol or Diesel models Improves cooling system reliability and cures "Whooping" Air Conditioning noises Preserves Compressor life if resistor hasn't been u/s for too long If no resistor here, older type 3 speed motor is fitted If resistor here, later type robust fan motor is fitted Upraded 100 Watt resistor working in situ Can save 75 ZT owners a garage bill between £300 - £500! A common fault exists mainly with models after 2003 (not facelift dependant) where you loose the LOW speed function of the cooling fan, due to failure of the under rated poor quality resistor. So this kit has been introduced by ourselves to avoid having to replace the whole motor assembly as the OEM resistor is not available anywhere in the world separately! Garages simply replace the whole cooling fan motor, control box & radiator cowling costing over £250 for the parts and probably over £200 labour! Main dealer’s diagnostic equipment (T4 Testbook) does not even recognise this problem with a fault code!! And their response to a customers who say their fan is very noisy “Oh they all do that” Price £26 (Postfree to members here) you can order this kit which comes complete fitting instructions. Pre-drilled resistor with integral heatsink Weather proofing heatshrink Ring terminals Nuts & bolts A copyrighted power point presentation on CD The components supplied in the kit are of higher quality and higher wattage than the original OEM part, giving your cooling system more stability and reliability. Economy kit price is £14 Undrilled Resistor with basic instructions & terminals. Cheaper option but takes longer to fit. Suitable for following models: All 75 & MG ZT ZTT petrol 1.8, 1.8T 2.0 KV6, 2.5 KV6 or Diesel CDTi and even the ZT 260 V8 4.6 There are 2 types of cooling fan motor: (pics below to identify yours) Kit required for: Later type 2 speed 2 wire with silver resistor (viewed through front grille) Kit not suitable for: Older type 3 speed 4 wire (no resistor fitted, hence kit will not repair these. Brush wear probable instead) Symptoms: Your radiator fan switches on and off quite noisily every 20 to 30 seconds or so with the air conditioning running. Others have described it as sounding like an aircraft taking off! Normal situation should be constant Low Speed fan operation as long as Aircon is set to On. NO LOW SPEED function of cooling fan due to the failure of the said resistor. This results in rapid heat build up in the condenser (in front of radiator) hence excessive pressure in the high pressure side of Aircon, which triggers the “trinary” switch. This in turn sends a HIGH SPEED fan signal to ECU. (built in fail safe mode) 10 seconds of high speed fan operation is enough to cool the system down to a safe level again, and so the cycle repeats itself. All above is assuming the air con is functioning correctly and has sufficient gas Any other symptoms like no fan rotation at all then this kit will not solve your problem and the motor itself is probably the culprit or relays etc in the control box next to it. You can tackle the mod yourself or give it to your garage to do as it requires removal of the front bumper assembly and requires some electrical/mechanical knowledge. Identify if you have a silver looking resistor approx 65mm long by 15mm wide with a black wire coming out of each end just behind the fan blades off to the right as looking from the front (this can be viewed through the front grille and should look like pic below) Location of resistor (can be viewed through the front grille by moving the fan blades slightly with long implement with ignition off) If there is no resistor then your car probably has the 3 speed 4 wire/brush motor therefore this mod kit will not cure your fan problem. A new motor would probably be needed as the older type had a shorter life. Please study the whole CD before fitting. A fitting service is available but we are situated in North Wales and it will still save you £100’s to travel to get this job kit fitted even if you have to travel : Enquiries to Tel 07831 457011 You are buying the modification kit in the first picture NOTHING ELSE! IMPORTANT PLEASE READ! JMA accept no responsibility for incorrect fitting or bad workmanship or poor fault diagnosis. This text, CD and photographs are copyrighted by JMA and may not be reproduced. There is no change to cars performance so no need to inform your insurance company This will not cure a completely dead fan nor will it repair a non functioning aircon system __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block Last edited by Jules; 10th October 2008 at 00:49..

26th March 2008, 11:55	#2
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Bump Due to recent requests here's the info again!! __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block