Driving Rad fan from Starter motor.

[TVRleigh]

I have read you can get extra power from the Fans if driven from the starter motor.

Could somone give some more info and how to wire the relays and fuses.

Thanks in advance
Leigh

[E2DJH]

I beleive you can in an older model, especially if you fit one of these:

http://home.btconnect.com/djbeer/id27.html

If in doubt, give them a call, David is extremely helpful.

[TVRleigh]

Well it a very older model. its not even a griff, bit a 400SE, but have put the griff Ali rad one with 2 Spal 2300 m3/Hr fans on.

Problem is I've allready spent a fortune. so will have to think about it.

[E2DJH]

I fitted it to my 98 Chim, and powerd it from the live on the starter motor. The beauty of this bit of kit is that you determine at what temp the fans come on at half speed, and then full speed. The existing otter switch is a failsafe. Mine is also set to carry on running after the engine is switched off, until it drops to the desired temp.

My reason for fitting was mostly to keep the inside of the car cooler by keeping the engine cooler. Having had it fitted for a couple of months now, i can definately notice the difference.

Cost about £120 i think

Disclaimer: i have no connections with the company other than as a happy customer

[tvr4ever]

Yep, Mod-wise 2 speed fancontrol, excellent piece of kit. Does wonders for the underbonnet temps.

Fred

[FlipFlopGriff]

You can get the cheaper option (£50ish) which you can adjust the temp at which the 1/2 speed come on and the full speed kick in as normal. This connects (or did) to the starter which makes the fans run a bit faster and will run on after the ignition has been turned off.
FFG

[tvr4ever]

FlipFlopGriff said:

You can get the cheaper option (£50ish) which you can adjust the temp at which the 1/2 speed come on and the full speed kick in as normal. This connects (or did) to the starter which makes the fans run a bit faster and will run on after the ignition has been turned off.
FFG

I choose the 2 x speed option so i could set the high temp a bit lower, it helps when you do trackdays.

[Ribol]

TVRleigh said:

Could somone give some more info and how to wire the relays and fuses.

If you want to use the starter supply cable as your fan power supply it's not hard to do.
You need two decent relays mounted somewhere they won't get melted or drowned. An ignition live supply goes to the otter. The other side of the otter goes to one side of both relay coils. The other side of both relay coils goes to earth. The live supply from the starter goes to one contact on each relay, the other contact on each relay goes to each fan. The other side of each fan motor goes to earth.

That should do it

[VictorMeldrew]

E2DJH said:

Mine is also set to carry on running after the engine is switched off, until it drops to the desired temp.

Will this actually do anything if the coolant is not being circulated? I'd have thought this would just cool the rad, but not really have much effect on the inevitable heat soak on the heads when the water pump stops. Cooling system wise TVR's are a bit skew whiff, with the rad being lower than the heads, so there would be no circulation due to convection either.

Now coupled with an auxiliary electric water pump, possibly plumbed in to the heater pipes, it would be a different matter.

Or am I completely wrong?

[Ribol]

VictorMeldrew said:

Will this actually do anything if the coolant is not being circulated?

IMO yes, obviously not as much as if the water was still circulating though but every little helps. If you cool the rad it draws heat away from engine via coolant and the fans being on move the hot air out of the the engine compartment - both better than doing nothing.

I always lift the bonnet up when I park after a long run to get the heat out of there ASAP, especially if the fans come on when parking.
The only thing I have changed on my car is a slightly earlier otter and recored the non leaking rad which was starting to lose its efficiency other than that is has worked fine exactly as it left the factory.