Fan/heater blower speed control from PreHeater (1 Viewer)

[hec4x4dk]

Hi.

I'm having some trouble with my PreHeater installation, as it draws all the power off the battery.. I have found that the fan is running at full or nearly full speed...

Situation is, that a PWM relay sits on the preheater circuit, and is connected to a white wire with red dots on the standard Toy circuit. I believe the intention is to have the realy signal a pulse to regulate the speed of the fan blower, as just a simple voltage (DC) will run it at full speed....

So Q is, am I correct to understand things that way? And if so, would my PWM realy be suspect of fault, or are there other reasons possible?

My blower runs quite as it should on normal ignition, and I believe the fan at some earlier point in time was running at a lower speed, not discharging my battery every tiHe...

For now I have just put a switch in between the preheater and the realy, and thereby not activating the blower thus saving huge amounts of battery power...

Any thoughts appreciated..

Thanks i advance...

Regards...

Henrik

 

[NMuzj100]

Don't have an answer to your question.

I am interested in the preheater though.

Where is your preheater mounted? How fast does it bring the truck up to temperature and what is your application? It it controlled by a timer or themostats?

 

[hec4x4dk]

I use a Webasto 5.7 Kw gasoline heater, mounted where PS fluid reservoir used to be (which is now slightly offset from there). It is controlled by timer, but I have an HJ60 with an Ardic with remote, and my 100 had a Hydronic with remote earlier on, also with remote. If I set the timer on 45 min it will normally heat my engine up fine (at moderate frezzing outside temperatures), in summer i use 30 min. It has a thermostatic control, meaning it will stop burning fuel at some point - if engine is left hot it only starts cabin blower, not the burner.

Beware to mount feed fuel lines away from heat, as heat bubbles will generate explosions in the heater... (this means your exhaust but also coolant lines that gets hot...)

Regards..

Henrik