As I always find the forum a treasure trove of good advice I thought I would return the favour with a brief résumé of my recent experience replacing the cooling fan on a ZT-T 190.
I had been experiencing wild fluctuations in engine temperature for some time along with loss of coolant and had gone through the process of replacing the thermostat. (Had some actual help from Simon SD1 with this and very helpful and sound advice from Dave Lincs. Thanks to both!)
Some ten months on and I noticed the air con was not cooling as previously. Then one morning in slow moving traffic the engine suddenly rapidly overheated, but after a minute or two the temperature went back to normal (?) and this pattern continued until I arrived home, a journey of five miles or so.
Lots of research on the internet and forum and the evidence seemed to point to an intermittent or non-functioning cooling fan.
I did the de-mist test and indeed there was no fan movement. The fuse for the fan was intact (80A!) and as I was rather dreading the seemingly inevitable dismantling of the front of the car, I thought I would order a repair kit from Jules just in case the resistor or relay were at fault, and meanwhile do any more tests I could while the fan was in situ.
In fact there doesn’t seem a lot more you can do without taking the front of the car off so I steeled myself to just get on with it.
Having taken the bumper off and gained better access to the fan and cowling I thought, in hope, I would try replacing the resistor. This was a gold resistor and presumably was a replacement for the original.
It had been properly installed with soldered joints and heat shrink. Though this was a bit of a shot in the dark, I duly replaced it in similar fashion.
Unfortunately the fan did not spring back into life and I realised I had to go back and be more thorough with my investigations.
Next came releasing the cowling sufficiently to gain access to the relay box in order to do some further checks and establish whether the fan motor was really kaput.
Shorting across the relay contacts as suggested produced no life from the fan while in situ.
No choice then but to remove the cowling completely. I made a bit of a song and dance about this and the cutting around the refrigerant pipes to the condenser. Did anyone at MG Rover really consider repair and replacement procedures for these cars….?
With the cowling now off the car I cut the wires to the fan and tested it directly with 12v. Still no movement.
On further inspection of the fan wiring loom to the connectors on the chassis to double check polarity I noticed that the plus and minus feed wires had melted themselves together. It was a struggle to separate them but I’m glad I took a look. A possible future underbonnet fire averted perhaps?
More reading on the forum re. replacing brushes, looking at the new and second hand motors available on eBay, and in consideration at the reduced current consumption offered by the Revotec fans I decided to order a kit from Jules. I do not have the figures for the amount of air the original fan was capable of moving but the Revotec spec quotes 3670m3/h.
I know that this decision may bring howls of derision from the replacing brushes camp but this is strictly my everyday car, and time spent on a possibly 18 year old old fan motor that may or may not prove to be reliable, could be time and effort wasted. Plus given the parlous state of the wiring having to deliver 37.5A to the original motor as opposed to a quoted 17A for the Revotec swung it for me.
The new fan arrived overnight and installing it in the cowling was not difficult following the supplied instructions.
In preparation for the job I had ordered some heat shrink with adhesive from Amazon, and after testing the new fan using the spade connectors included with the kit, I decided to simply solder them together and put one or two layers of heat shrink over the joins.
The routing of the wires to follow the original path proved interesting and took a couple of goes but eventually it all squeezed into the plastic sheathing and back in position.
Since fitting the fan the all seems to be well. The air con has sprung back into life thanks to the compressor now being allowed to engage and the fan certainly demonstrates that both speeds work.
Thanks to Jules for his patience and experience. It’s a long way to Colwyn Bay for some of us to have this fan fitted and so I would not hesitate to recommend this kit as a solution for replacing the cooling fan on a ZT-T.
