I am looking for a switched power source under the hood that becomes hot with the switch and stays hot during cranking, and it needs to stay above 10.3v. I need it to power the new throttle body ecm. The ones that I know of drop down to <9.8v. Any help will be greatly appreciated. Thanks, Chuck
The lower voltage is no problem to trigger a relay that can supply full battery voltage to anything you want. I used the Pertronix relay, triggered by the ignition wire to keep a full 12v to my Ignitor II setup. Works great.
Eric when you say ignition wire is that the big yellow wire going through the fire wall? Do you by chance have a picture of how you wired the relay? Thanks, Chuck
Operate the relay coil from the normal ignition feed. Many batteries will fall below 10v while cranking.
I don't have it in front of me at the moment to get a picture - but all I did was trigger the relay with the wire for the "I" terminal from the solenoid, which is the + side of the coil. My coil and ignitor II need full 12V all the time.
You are welcome .......... I have a couple pics to share. First is from the instruction sheet for the Pertronix relay. Nice thing is they numbered it to correspond with just about any plain old relay terminal numbering. Substitute your ECM for the coil in the picture and you get the idea. Second pic is the wiring in my car. Normally it is tucked in a bit more but I pulled it out for the picture so you can see the purple wire spliced into the "I" terminal wire. I soldered these connections and then covered it in liquid rubber electrical sealer.