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Joshshorty
15th November 2013, 09:35 PM
Hey guys
So I have commodore thermos on my shorty mav
Currently just wired up with a manual switch
Does anyone know how to rig up a warning light
In cab that comes on when the fan is off
Weather it's a blown fuse buggered relay broken wire
Or even when the switch is off
Anyone know?
Cheers
Josh
megatexture
16th November 2013, 11:40 AM
Just run a led light in the cab inline with the fan and that way you can see if its on when the lights out its off etc.
threedogs
16th November 2013, 11:48 AM
Jaycar will have a small LED or just change
the toggle switch to one with an LED in the stalk
Winnie
16th November 2013, 11:51 AM
I think you could run a wire from the fans through a normally closed relay to a small LED.
megatexture
16th November 2013, 12:16 PM
Jaycar will have a small LED or just change
the toggle switch to one with an LED in the stalk

That will indicate that the fans switched on but not that the fan is actually on
mudnut
16th November 2013, 05:48 PM
That will indicate that the fans switched on but not that the fan is actually on

Just buy a relay with a "normally OFF" terminal, so that when the relay has no power, it will turn the light on. Just remember, that it will be on, more of the time in cold weather.
mudnut
16th November 2013, 06:10 PM
Ok, If you are really interested in what the fans are doing, then an in line dc shunt ($6-$20) and a 100 mv digital voltmeter across it with a resistor for the power supply ($15-$30) off fleabay, will tell you if the fans are drawing current or not. The only thing is I don't know if the above mentioned devices will handle vibration over a long period.
megatexture
16th November 2013, 08:40 PM
Seems like alot of expense and effort for a fan indicator when a light will be so cheap and simple lmao.
mudnut
16th November 2013, 11:04 PM
I thought the idea was the light on if the fan is off or blown fuse, etc, that is why I suggested the normally off for the relay.

P.S. I was just thinking out loud with the shunt idea, as I have had trouble with thermo fans, before. EG, high resistance joints etc.

P.P.S I apologise for the fact I've just drawn a switch instead Relays and fuses but paint is a real pita.
philfree
17th November 2013, 09:45 AM
i like mudnut's idea and quite practical and easy to do but if you wanted to go with the shunt route to make sure the fans are drawing power i think the autron guages come with a shunt and you maybe be able to set them up with an alarm so when it has no current flow it brings the alarm on just a thought