Alright so I've been working on my uncles 2003 Ford explorer for a while, It has a parastic drain on it and after countless hours of testing I've determined that the PCM doesn't completely go to sleep when the truck is turned off. So not wanting to shell out a ton of cash for a new PCM my uncle wants me to intall a battery cut off switch, easy right? No.

The problem is he doesn't want a simple switch at the battery post he wants a dash mounted switch because my 16 year old cousin is going to be driving this truck and she doesn't even know how to open the hood. So I came up with something that I thought would work. Older Fords use a starter solenoid that is mounted on the fender so its basically a huge relay.

I thought of using one of these and splicing it into the negative battery cable and then mounting it to the plastic fan shroud. Then I would wire a hot wire from the battery to the ignition switch terminal on the solenoid. Then I would run a negative wire from the base plate of the solenoid to a toggle switch on the dash. When the toggle switch is switched on the solenoid is activated and power flows through the negative bat cable thru the solenoid and to the bat. Sounds like it would work right? Well after hooking it up to a spare bat after 45 seconds the solenoid started smoking and then shorted out, so they are def not designed for constant amperage.

So my question is does anyone have another idea on how to create a dash mounted battery cut-off switch other than a pull type switch?

 

So it looks like I can use the same set up as above but instead of a starter solenoid I think I can use this:
http://www.amazon.com/PAC-PAC200-Bat...6661866&sr=1-1
Its rated for 200 contunious amps and 300 amp surges. I'm pretty sure the most amperage that is used is when the starter is activated and its about 150 amps.

 

alright I think I've answered my own question, I'm gonna use the PAC 500 battery isolator relay. It can take 500 amps constant and 700 amp surges. That should be more than enough.

 

How about this. I have installed 1 for a customer it works great. It take less than 10 min to install.

http://www.prioritystart.com/

 

wow so much better, amazon has the promax for 82 bucks. I figure I'll have my uncle get the better one since he has a few accesories on the truck. Thanks a lot MDTAHOE.