Actually, that is it's role. Battery temp is monitored by the PCM and uses that info to control the charging voltage.

 

ok, ask simple question.... Now I know! Thanks!

 

Wow.....learn something new here every day! I had no idea that there was even a battery temp sensor. :Wow1: Guess with all the power demanding equipment on vehicles these days, it has become necessary.

 

so thats what the little button thing is on the bottom of the tray.

 

Yeah, that's it.

 

mine was actually up and out of the hole it sits in, and was off to the side of the batt. I changed battery this weekend, and seen where it was supposed to go.
My 3 conductor positive batt cable was sporting one of those cheesy sheetmetal clamps from previous owner, so I modified it with a nice larger cable.... solely to the power distribution box. I recrimped an eye on the starter cable, and put it and one more hot wire under that lug. So far, so good. (I wasn't in the mood to fish the old wire out, and put a new one in clear to the starter that day). Cost? $15.
I will do the negative side next. Same deal there, I will go to the waterpump lug with one nice conductor, and put the body, chassis grounds under that lug.

 

Go directly to the block. It's a better ground.

 

Good idea Randy. All the different metals used today that juice has to run through...aluminum bolted to iron.... etc, has to be hell on conductivity after about 10+ years!