Electric Fan Keeps Cutting In..

Just had the car 1 week now ...and very pleased with it !!. I'm currently using it everyday (15/20 mins journey each way)and have noticed a "minor problem" with the electric fan. It seems to "cut in" more noticeably than other cars i've owned.
Is this a characteristic of the ZT260's?. This is despite the fact the car cannot be too hot as temp gauge =o.k + car not driven too far /thrashed/too cold outside !! etc. For example - Freezing cold (-2 degrees) on Friday night. Went out in evening and after a journey time of half an hour pulled up to stop,with engine running and fan cuts in.I had a look at "Other Blogs" out there at the weekend eg. MG-Rover.org and they talk about a "radiator recycling" and point towards a resistor failing?. This morning I ran the car in without aircon/climate on and fan didn't come on at all.
Any tips?. Is this a fault (resistor OR Other?) ...or is it normal?. The car came with a 3 month warrenty and i'd like to get it sorted if there's something at fault,under the warrenty (if it's covered).
Thanks.
Andrew M

Keith (over at 75&ZT club) explained this to me in detail... err.. several months ago though so from what I remember:

With the AC on the Fan will be on all the time. it will cut out every so often but shortly kick back in. With AC off the Fan will only kick in to cool the engine.

Im sure others will be able to clarify/confirm this?


Oh and welcome to the fold :)

some cars were fitted with the 3 speed fan some with the 2 speed fan.
on the three spedd the speeds are controlled by the control box, on the 2 speed the low speed is catered for by a large load resistor.

this resistor can fail, leading to the high speed fan cycling on and off, this can lead to other problems such as burst radiators.

if you do a search over on

http://www.the75andztclub.co.uk/forum/

there are various articles on the topic.

BTW I have the high speed fan and have only ever seen it kick in on high so far !!

Thanks Guys;

I'll give it another week of "experimenting" with Air Con On / Off etc..+ take a look at the 75/ZT Forum (Thanks).
Otherwise,as said previously.. Car is brilliant & no other faults...and That sound!!..Especially as I tend to leave @ 6.30'ish am most mornings and love the neighbours to wake up to a "V8" chorus..

Kind Regards, Andrew

talking of the V8 dawn chorus, the guy round the corner is rebuilding a V8 MGB GT, and uses my car as an alarm cllock every morning- he also says when he gets to a tricky bit on the car the thought of mine inspires him :D

Has anyone got any experience of or suggestions for this situation. Last November drove to work perfectly happily and when it came time to come home the battery was completely flat. The cause of this was that the radiator fan had remained on. AA man charged battery but was unable to switch the fan off - si I drove it to the garage and they too couldn't switch it off short of taking the fuse out. They could make no progress until a day later they said the only solution was a new control box. Two problems there - first there were none available til January at the earliest and second thay cost several hundred quid. Eventually they returned the car and showed me how to remove the fuse each time I stopped driving the car. However as if by magic the fans went off as normal again and we have had no bother ever since. Obviously that's good news but equally obviously I am worried it might happen again!

Any thought would greatly appreciated - Merry Christmas and a Happy New Year to all you afficienados of this magical motor.
Julian

Is this the same control box thats in the passenger footwell??

If it is, could it be possible water intrusion?? some cars have short sunroof drainage tubes that may leak water onto the electrics down there causing odd behaviour.

have had a similar experience with an aftermarket pacet fan on a range rover, only the fan was equipped with a variable temp switch that sensed the radiator temperature and cut in when hot enough. I went out to the car on the morning and the fan was still running from night before. the fan went off as soon as i played with the variable temperature knob, so the switch had stuck. In my case the solution was to wire the sensor/fan to ignition live rather than permanent.

I found this on ebay
http://cgi.ebay.pl/Rover-75-MG-ZT-V8...QQcmdZViewItem

Could anyone please tell:
What resistance (Ohm)and what power (Watt) should the resistor have?
Thanks in advance Sledge Hammer

Not sure, but I think thats the one made by one of the guys from the 75ZT club. JWA industry? or Jules??

I think he sells them on ebay too, so have a look on the UK site - may be able to offer the required info.

Quote:

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Originally Posted by SH4RKY

Not sure, but I think thats the one made by one of the guys from the 75ZT club. JWA industry? or Jules??

I think he sells them on ebay too, so have a look on the UK site - may be able to offer the required info.

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Jules has been making them Ian.

His number is 07831 457011 if you want to order one.