Switch size for radiator fan?

[jtrashy]

I want a switch on the ground of the radiator fan, how big should it be?
Thanks!

[Ahwahnee]

Are you wanting a switch to manually turn on the the fan?

I used the usual 'fog light' switch that fits into the dash pod (replacing a dummy in that slot). It is 2 position so I can select either of two speeds.

It has been a long time but I think it is just switching a relay, hence not much draw.

But switching the ground may require more an possibly only permit turning the fan off (overriding the thermo switch).

[vanagonjon]

usually a switch on the ground side will disconnect the circuit and stop whatever you are controlling. You want a switch in parallel with the thermostat to override and run the fan when you want. There may be up to three fan speeds, so you need to decide which thermostat contact(s) you are overriding.

John

[jtrashy]

I should have givien more info......
i trying to troubleshoot my running temp which is 193-195 when its hot so my fan is running for 6+ hours on the freeway which isnt buying me anything. So im only looking to turn it off when desired, not on

Whats the easiest way to turn the fan off ? my thought was a switch to the ground but im open to suggestions, easier the better as its somewhat temporary

[Ahwahnee]

On my 84 the radiator fan has its own (16a red) fuse. It is in position 7.

Pulling that would shut it down.

[jtrashy]

Simple, I like it

[MarkWard]

Hello, you don't specify your year, but the later vans with the "H" type fuses had a 30 amp radiator fuse. So in answer to your question, without adding a relay to the ground side, you'd need a switch that can handle 30 amps continuous. That should be a very expensive toggle switch. I think later vans with factory AC had a 50 amp blade fuse for the high speed. So, you'd need a switch capable of handling 50 amps continuous.
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[shagginwagon83]

Could you not have a simple 12volt toggle switch to control the ground through a relay? Basically when the switch is sending 12volt to the relay, it bridges the ground connection. It would also save you from running very thick wires into the cab.
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan

[vanagonjon]

Not living in a really hot area (New England) I would think that if everything is working correctly on your van the fan should run at the speed required to keep the temperature at the correct range. If running the fan does not cool down the coolant sufficiently to stage down the fan speed, maybe something is wrong. I would not turn off a fan that was doing its job correctly.