JCB 525-60 Electric Fan Continues Running

[Sparkplug]

Has anyone with a 525-60 experienced the Electric Bonnet Extractor Fan continuing to run for Hours after switching the engine off? The fan must either have a Timer or take a Temperature Reading from a sensor that is causing this problem - any help much appreciated

 

[Ionic]

Has anyone with a 525-60 experienced the Electric Bonnet Extractor Fan continuing to run for Hours after switching the engine off? The fan must either have a Timer or take a Temperature Reading from a sensor that is causing this problem - any help much appreciated

Have you solved this issue. I'm still trying to troubleshoot it and it seems that the fan is supplied by a relay that is controlled by a module called RDM. No idea what or where it is.

 

[Sparkplug]

Sorted in the end - not a problem that any one really knows about - there is a Slave ECU tucked away under the rear chassis on offside - lie on your back and shuffle under by tow hitch and look up to your left - you will see it bolted high up - just one plug into ECU -- and when I had changed it the system did not need a laptop to install - apparently there is a built in Timer in the ECU for the fan which JCB knew about from other failures but, it is information that my JCB contacts over many years could not offer a solution to the problem. If you want the part number I can get it next time I am in my workshop . The 2015 525-60 is now for sale, so I have only shunted around the yard once or twice and not got it hot but the fan if behaving now!

 

[Ionic]

Sorted in the end - not a problem that any one really knows about - there is a Slave ECU tucked away under the rear chassis on offside - lie on your back and shuffle under by tow hitch and look up to your left - you will see it bolted high up - just one plug into ECU -- and when I had changed it the system did not need a laptop to install - apparently there is a built in Timer in the ECU for the fan which JCB knew about from other failures but, it is information that my JCB contacts over many years could not offer a solution to the problem. If you want the part number I can get it next time I am in my workshop . The 2015 525-60 is now for sale, so I have only shunted around the yard once or twice and not got it hot but the fan if behaving now!

Thank you so much for the piece of info.
Yesterday I started by removing the cab panels searching for that unit but only found the MECU, Livelink and a type of slave module (something about the seatbelt I believe). I do have the schematics for this model but it doesn't show the location of the components so, it's kinda annoying. I'll check it Monday and will let you know what I find.

Thanks brother.

 

[Sparkplug]

I found the invoice for the Slave ECU - the part no is : 728/P6782

 

[Ionic]

Giving some feedback.
Ended up replacing the slave ECU and the ambient sensor since it was broken but the fan keeps running non stop even with ignition off.

The funny thing is that it stops when you turn ignition on again.

Still no clue what the problem is but I'll probably just install a relay to disconnect that circuit once ignition is off.

 

[Sparkplug]

Thought I had fixed it but had it out the other day and the new ECU has not been the answer as you found out - not sure of next move - JCB have not come up with any other suggestions - yes my fan stops when you turn it back on?

 

[Ionic]

Tomorrow I'll install a relay to open the coil negative of the Aux Fan relay, when ignition is turned off.
It will stop the fan for sure. Not sure if it will be an issue for the engine. Maybe that fan is supposed to run until the temperature of the engine reaches a certain point regarding ambient temperature.
I just don't know and the 1800 and something pages of the service manual has nothing about it either...

 

[Sparkplug]

I was told JCB Service knew about the problem and suggested the ECU change would cure!
Apparently the fan should run on for 90 seconds only, but what fires it up in the first place? Is it taking a temperature reading off the water jacket temperature sensor? Maybe I should try changing it.