12volt switched supply in engine bay? I have a heated filter that I need to run an ignition switched 12volt power supply to. My filter is near the passenger headlight. It is a 200w heater so my supply needs to be able to handle that.

Does any one know of a power supply? I have bypassed my pre heater and was thinking of using that as a power supply but I don't know if it is continuously on while the truck is running?

 

in my 01 there is a fuse box near the drivers side battery, it has an ign 12v+ to handle 200w heater just wire in a relay, and use the keyed hot (12v) to trigger it. then again you seem to have an older truck maybe there isn't a fuse box in that spot

 

Use a relay. It has never been easy for me to tell what load a 12v source will handle until it blows something. The easy way is to use an inline relay, rigged to the battery.

Then, any switched source will suffice as a trigger with no worries.

 

Where might I get a relay?

 

The heater grid relays are 12 volt switched. I used the one closest to the firewall (back one) as my 12 volt switched source for my Hadley air horn compressor. They are on the drivers side of the engine by the injection pump. My truck is a '98 12 valve. -Glen

 

You can get relays at NAPA or most Auto parts stores.You need to be concerned about the amperage of the relay.

Floyd