Is this a solenoid? Is this a "key on" power source I could use for a solenoid/battery isolator? I am trying to upgrade my wiring for a camper.

Thanks for the help!

 

Yup that's a solenoid. Not sure what it controls since I'm pretty sure I don't have one there on my truck. Where does the black cable go to ? I'm assuming the green cable is a ground ? I'd peel back that shrink wrap on the green cable, kind of looks like corrosion has gotten in there.

 

The green goes to the battery lug, ground I think. You are right though, looks like it needs to be replaced.

This is just behind the passenger battery, I was swapping out to new batteries when I saw this and took the photo.

 

That would be your grid heater solenoid.

 

as jhenson said. grid heater solenoid the green wire is actually a fuse link to the positive lead of the battery, i think it is a 200 amp link. you do not need the grid heaters. if you use the solenoid for a disconnect there is a 16 gage green control wire to it from the ecm. you need to connect a resistor of about 24 ohms 10 watt between the wire and ground. to fool the ecm in thinking the solenoid is ok. a second code is thrown if you wait to start below 55*. every time you turn the key on the wait to start light comes on to teach you to wait to start, below 55* the ecm activates the solenoid and the ecm looks at the battery voltage for the drop to make sure the heaters are working. by not waiting to start the ecm can not tell

 

Thanks for the info! Don't I still need the grid heaters though? I live in a cold climate and they seem to come on quite a bit at start up.

Switching gears on this, as what I am really in need of is a switched 12 volt power source to activate a solenoid/battery isolator that I installed on the driver's side next to the fuse box. I can't remember what I had tapped into way back when, but it needs to be reconnected and so I thought I'd check with you guys that may have done this already. Thanks for the help!

Conor