Engine Fan

[Shaker]

Hi, can anyone help me with this one before I get to deep. My Kv6 Connie's fan keeps coming on while driving,a couple of weeks ago on a weekend away it stayed on even after checking in at the hotel getting changed etc came down still going. I managed to disconnect the battery until the morning. Reconnected it and all was fine for about 3 weeks until, coming home from work yesterday when it was on all the time, got home still running, so disconnected the battery again. This morning a soon as I connected the battery it started again and hasn't stopped. I've just swapped the resistor for the gold one and its still running. So my question is, before I start stripping the fan off a parts car, is the fan on the Connie goosed and needs replacing or is there anything else I can try? Thanks.

[vitesse]

Sounds like a relay sticking inside the control box, not much fun to get at as the whole front has to come off.

Hopefully Arctic, or Stocktake might have a better idea than my guess.

Regards

[Shaker]

thanks vitesse, I'll wait and see if they have any suggestions. I don't want to go to the trouble of stripping the fan from the parts car to find it doesn't cure it.

[T-Cut]

The fan motor has a permanently-on live feed. Switching is achieved via relays on the earth side. A sticking-on or faulty relay will certainly cause the fan to run without the ignition being on. Your description of events suggest this is the likely cause. Of course, the relay may be activated through a fault in the control side. To 'stick on', the relay has to be activated first. Swapping with a new one should give you a clue.


TC

[Shaker]

Thanks TC
are these the relays that are in the fan assembly or the one in the fuse box?
Sorry if thats a basic question but I'm no sparky and fortunately my MGR's haven't had many faults so ever had to search for components.

[T-Cut]

The relays switching the fan on are in the plastic control box mounted behind the fan guard/frame on the nearside.

Is your fan a 3-speed or a resistor moderated 2-speed? The latter has a silver or gold coloured resistor mounted on the frame behind the fan blades. Look through the blades in the 2 o'clock position.

You'll find everything you need to know somewhere on the forum, once it's clear where the problem is.

TC

[stocktake]

Almost certainly a relay problem as described, Other causes can be:
The loss of signal from the temp sender.
An overheat situation causing the fan to run after engine is off.

[dattrike]

Not sure, but does relay R5 in the engine compartment fuse box supply the feed for the cooling fan?
Might be worth substituting it with another if it does (may be welded on)
https://www.ebay.co.uk/itm/GENUINE-ROVER-75-MG-ZT-99-05-UNDER-BONNET-FUSE-BOX-YQE000210/223459787561?hash=item34073dc329:g:CBMAAOSwJ4hY-Iqs

[SD1too]

... does relay R5 in the engine compartment fuse box supply the feed for the cooling fan?
No David. That's the heater blower motor relay.
So my question is, before I start stripping the fan off a parts car, is the fan on the Connie goosed and needs replacing ...
Steve,

You don't need to go as far as stripping a complete fan system from another car on the evidence you've presented so far. All you need to do is to check the slow speed relay. This is the small one in the centre position in the control box. You can either do this with a multimeter or by substituting the same relay from your other car.
Relay problems are rare so be prepared for disappointment.

Simon

[Arctic]

Almost certainly a relay problem as described, Other causes can be:
The loss of signal from the temp sender.
An overheat situation causing the fan to run after engine is off.

A little photo to accompany Dave's comment regarding the relay above.
https://i.imgur.com/NZZoiCKl.jpg1

It still remains you will need to remove the front bumper & slam panel,at the least peel back the fan cowling on the control box side to replace the relay or both ? other than that you would need to remove the fan from the car, if your car is gassed you would be better cutting the cowling round the A/C union joints, that way you do not disturb the gas.

allow a minimum of 2.5 hours to do the job.

[vitesse]

Steve, not need to cut the cowling to remove the fan which you probably already know but not the OP. Did a replacement fan job yesterday so it's fresh in my memory. With the waist 8mm bolts removed and the clips under the cowling, there's enough play to slip the cowling off the top pins and pivot the righthand (facing it) side of the cowling outwards. You can then access the three usually stubborn torx screws. Done about eight in this fashion, only cut the cowling the first time.

Only 2.5 hours, I thought our time yesterday (me & the owner) of just over 3 hours qualified for Mr. Guiness' book and that was with no snags.

Regard,

Mike

[Shaker]

Morning all and a big thanks to all who replied I helped. I've got the control unit out, without cuting anything there were no torx screws either!
It was a sticking relay as soon as I prised it out the contact freed so I connected the battery and the fan stayed off.��
However the contacts are burnt so I'm cleaning them with a bit of 2000 grit paper to get me over this week, so the question is where can I get a new relay/s from. I can't use the parts car as that's a diesel, thanks again.

[vitesse]

And thanks for the update, all too many forget to come back with the answer to their problems.

The stubborn torx screws hold the fan in place, obviously you didn't need to touch these.

I've got several relay boxes surplus to needs, and you're welcome to any relays FOC but would hope that someone more local can assist. Otherwise PM me.

Regards

[SD1too]

... where can I get a new relay/s from. I can't use the parts car as that's a diesel ...
Yes you can Steve. Open the diesel control box, remove a relay of the same physical size and fit it to the car you're working on.
It's only the whole control box assembly which cannot be exchanged between petrol and diesel cars. The relays are common.

Or take up Mike's kind offer. :D

Simon

[Shaker]

thanks Mike, Simon. I've just put it al back together and the fan is staying off. Based on that its now going to be next weekend, assuming it doesn't rain, before I can attack the diesel parts car. So thanks Mike I'll try that route first.

[Arctic]

Steve, not need to cut the cowling to remove the fan which you probably already know but not the OP. Did a replacement fan job yesterday so it's fresh in my memory. With the waist 8mm bolts removed and the clips under the cowling, there's enough play to slip the cowling off the top pins and pivot the righthand (facing it) side of the cowling outwards. You can then access the three usually stubborn torx screws. Done about eight in this fashion, only cut the cowling the first time.

Only 2.5 hours, I thought our time yesterday (me & the owner) of just over 3 hours qualified for Mr. Guiness' book and that was with no snags.

Regard,

Mike

Hi Mike.
I worked along side Stocktake at one of our meet a few years back and if my memory serves me right we did a complete fan change with car put back together in 1hr 50minutes which was our best time to date, I have a V6 fan to sort out in weeks time or so I will see how long it takes. ;)

[vitesse]

Hi Mike.
I worked along side Stocktake at one of our meet a few years back and if my memory serves me right we did a complete fan change with car put back together in 1hr 50minutes which was our best time to date, I have a V6 fan to sort out in weeks time or so I will see how long it takes. ;)

Remarkably swift time by the dynamic duo :bowdown: - will be doing another one myself mid Nov but don’t expect to better my time as this latest one was relatively snag free.

Mike

[Arctic]

Remarkably swift time by the dynamic duo :bowdown: - will be doing another one myself mid Nov but don’t expect to better my time as this latest one was relatively snag free.

Mike

Hi Mike.
Fitted a two wire 2speed to a launch car today 2 hours including a new Shannon tube well chuffed with the time mind you all the nuts & bolts cam unless lovely was quite surprised, really nice car too white connie owned by Mason.

He did have a bit of luck with him though the other day as he drove through some flood water and the engine cut out, he got himself towed out with out trying to start the car, because the Shannon tube which was original was like a birds nest if sucked the water up into the air filter but did not Hydrolock the engine very lucky, as above new Shannon tube now onboard ;)

[vitesse]

Steve,

Got another fan job quite soon but no way I’m going to beat your two hour job unless God decides to give me back some youth while retaining the experience I now have.

Lucky owner. Heard from Dave that my latest batch of VIS motors might be delayed, something about flood water and his shed and el.power - thought if anyone he would have gas lamps.

Mike

[stocktake]

Steve,

Heard from Dave that my latest batch of VIS motors might be delayed, something about flood water and his shed and el.power - thought if anyone he would have gas lamps.

Mike
Not managed to work out the gas or coal fired lathe yet Mike :D

Power has been restored I just dare not touch anything unless I have my wellies on :D :D

[bl52krz]

You not been flooded out have you Dave?Hope it has not got in your stock.

[stocktake]

You not been flooded out have you Dave?Hope it has not got in your stock.
Not flooded David as its quite hilly here, just everything is so damp, not a nice place to sit for hour after hour just now:o