Odd fan behaviour

reblack68 · Unread post by **reblack68** » 05 Dec 2008, 23:14

In this cold weather I've been using the heater fan on full power and I've noticed something a little odd.

When I floor the throttle the fan speed picks up, then drops when I release the throttle. The obvious answer is that it's the alternator kicking in but this happens long before the revs pick up (it's a 1.9TD, it takes a while

).

My feeling is that something is drawing a lot of current on low throttle, but what?

Does anybody have any theories?

Unread post by **Peter.N.** » 05 Dec 2008, 23:30

Mmm, sounds as though the pressure on the throttle is disturbing a faulty connection in the supply to the heater. You can check if something is loading the battery by connecting a voltmeter across it and checking when you depress the throttle.

DickieG · Unread post by **DickieG** » 06 Dec 2008, 07:49

Is this happening the first time you floor the throttle after starting? If so then what's happening is that by applying maximum drive it causes the glow plugs to turn off, hence removing a significant load on the electric system = faster fan speed.

citronut · Unread post by **citronut** » 06 Dec 2008, 13:49

or the sudden exceleration the heater plug conector is moveing giveing a beter conection

regards malcolm

reblack68 · Unread post by **reblack68** » 06 Dec 2008, 23:41

DickieG wrote:Is this happening the first time you floor the throttle after starting? If so then what's happening is that by applying maximum drive it causes the glow plugs to turn off, hence removing a significant load on the electric system = faster fan speed.

That'll be it. It's not just the first time, but it's in the first few minutes.