Cooling Fan

[muddypaws]

Hi. I have a Pacet fan fitted to my L/weight which in turn has a V8 engine installed so clearance between the radiator and the timing cover is a bit tight. The Pacet is fitted on the front of the radiator blowing through it. Since fitting the fan, the original cooling issues have been resolved however, the fan drains the battery like nothing I have ever seen. The alternator is new, the battery is a new heavy duty (130ah I think) and the starter is new. I have had the battery tested since purchase and it is fine. All the wiring is good and connections are tight. At fast idle (1200-1500rpm), output at the battery is about 14.6v.

My problem is the starter is one of the RR hi-torque type and if the battery voltage drops slightly to below 12.5v, it will not crank. It is an all or nothing so no slow cranking, just silence. If the fan has been running on the motor for even a short while and I switch off eg at a petrol station or more irritatingly during RTV trials, I have to sit and wait for ten minutes with all ancillaries off and the fan disconnected whilst the battery recovers enough to prime the starter which is madness. I would like to keep the starter because it is nice and powerful and spins the motor up beautifully.

My question is does anyone know if this is normal with a Pacet type fan and are there any other electric fans in use by forum members which have a lower current drain.

Many thanks.

[FridgeFreezer]

Sounds more like an electrical issue than the draw of the fan itself - even big fans only draw 20-30A when running which means it shouldn't be flattening your battery. Try measuring the battery voltage with the engine running & the fan on - it should be 13-14v. If it's dropping down and draining the battery, your alternator might need replacing.

There could also be issues with your starting circuit if your starter is that fussy about voltage - do you have good battery connections and good earths all round?

[LEAFERS RULE!!!]

Hi. I have a Pacet fan fitted to my L/weight which in turn has a V8 engine installed so clearance between the radiator and the timing cover is a bit tight. The Pacet is fitted on the front of the radiator blowing through it. Since fitting the fan, the original cooling issues have been resolved however, the fan drains the battery like nothing I have ever seen. The alternator is new, the battery is a new heavy duty (130ah I think) and the starter is new. I have had the battery tested since purchase and it is fine. All the wiring is good and connections are tight. At fast idle (1200-1500rpm), output at the battery is about 14.6v.

My problem is the starter is one of the RR hi-torque type and if the battery voltage drops slightly to below 12.5v, it will not crank. It is an all or nothing so no slow cranking, just silence. If the fan has been running on the motor for even a short while and I switch off eg at a petrol station or more irritatingly during RTV trials, I have to sit and wait for ten minutes with all ancillaries off and the fan disconnected whilst the battery recovers enough to prime the starter which is madness. I would like to keep the starter because it is nice and powerful and spins the motor up beautifully.

My question is does anyone know if this is normal with a Pacet type fan and are there any other electric fans in use by forum members which have a lower current drain.

Many thanks.

Sounds to me as if the battery is still not big enough to run the fan whilst the alternator is not charging you may need a deep cycle posh one or try a chuffing great wagon battery (like me, never had a fail to start yet) they are designed to run stuff for long periods with no charge input from the alternator, if still no good is the wiring to the starter big enough its surprising how much power you can loose if the wire is too thin,(i once tried to jump off a digger with a pug 309 and cheepo motorworld jump leads would only just click the starter soon as we used big thick leads and another tractor it was away no bother)