Battery pack cooling fan problems

[Amanda Newman]

Help - our local garage has replaced all the batteries with the Trojan T125 but we are still having problems with the cooling fan. We have replaced it with a new one, supplied by GG, but it is still not working and as a result the batteries will not fully charge and also we are unable to equalise them. Plugging in the BMS software results in the following information:
State of car blinking Red: fault detected and informs us that the car has missed three equalisation cycles. The Charge status is Red: charge shutdown - no reason in the message field. The Cooling fan is Red: not running but supposed to. GG have proved to be useless as they cannot inform us what is wrong when I supply them with this information. The car is running okay but not fully charging and we want to know if we should be using it when we are unable to equalise it. Can anyone throw any light on this problem, because we are beginning to think we will have to try and sell it if we are unable to get it serviced here in Wales? I hope someone can help us and I look forward to hearing from someone.
Many thanks in anticipation of your assistance.

[Tim]

Is the cooling fan running but the controller doesn't recognise that it is, or does the fan not run at all?

[Amanda Newman]

Many thanks for your reply and the cooling fan is not running at all.

[MB]

It could be the cooling fan or it could be a fuse.

Check the fuse box first. If that doesn't solve the problem, you can get a replacement fan from Maplin Electronics - they're the same fans as used in PCs, from what everyone can make out. Total replacement cost is around £5.

[Amanda Newman]

Thank you for replying Mike. We have checked the fuses and we have replaced the fan with a new one from GG. We were experiencing problems with the cooling fan before we changed the batteries and unfortunately it has not worked since. I look forward to hearing from you with any further suggestions. Many thanks.

[aloening]

Just a quick question - is the fan actually for 'cooling' the batteries? I suspect that the one that extracts from the tube behind the drivers seat (within the battery compartment) is just for removing the small amount of hydrogen that the batteries emit. I have seen the battery temperature in my car exceed 35C on an equalisation charge and this did not limit the total charge.

There is probably also a fan in the charger itself - that would be for cooling - but even then, my reading of the manual indicates that charging is just slowed down, not terminated early.

There are a couple of very small fuses fitted to the EMS and an associated relay above that. Have you checked those? I am not sure of the size but could look at my car tomorrow if you need to know.

[Amanda Newman]

Many many thanks for your reply. We are uncertain what fan we replaced but will take another look under the seats and get back to you if we require any further help. I really do appreciate all the replies I have received so far as we are at a loss what to do next. Thank you.

[shadey]

make sure your fan is wired correctly, the black wire is an earth, the yellow wire produces about 5v and the red 12v. The car should charge even with the fan removed, you will just get a yellow/red charge light instead of a green flashing light, you may have another problem. try using bms and see what the soc state is whilst charging.

[Tim]

make sure your fan is wired correctly, the black wire is an earth, the yellow wire produces about 5v and the red 12v. The car should charge even with the fan removed, you will just get a yellow/red charge light instead of a green flashing light, you may have another problem. try using bms and see what the soc state is whilst charging.

I think that the red is the supply to make the fan run, so there should be 12 Volts on it when charging to make the fan run. So that's worth checking.

I suspect that the yellow is a signal back to vehicle to indicate that the fan is indeed running.

If you unplug the fan and haven't got 12 volts between red and black when trying to charge then the problem is in the supply to the fan.

[Amanda Newman]

Thanks fellas for all your help and information. We have removed the back seat and tested the supply to the fan under the rear drivers seat with a electrial tester pen. It seems the supply to this fan is okay as the pen lights up when touching the cables. Concerning Adrian's reply we do not know where to check the fuses on the EMS. Could you explain in more detail where to look for these (or a diagram would be great). Also we have not removed the cover to the charger to have a look as a little worried we might do more damage and not sure how to get it off due to all the wiring (and also the fact that it states if you dont know what you are doing then dont touch!!). Apologies for our complete incompetence. As before the BMS is still saying the cooling fan is not running but supposed to, the state of charge is on charge shutdown and the reason in the message field is we have missed 3 cycles for equalisation. On the dials the SOC is at 30%. The car runs perfectly well but we are still unable to fully charge the batteries and therefore we are unable to equalise the car. I think we may have to organise someone to come all the way to Wales to service our car. Any further suggestions gratefully received. Many thanks.