Ok so I finally got my new used truck running and the temp gauge just dropped and wont move now?I have replaced the thermostat and housing(i cracked it lol).The heater core has been blocked off due to it leaking.Any ideas would be great.

 

Have you checked the temp of the coolant with a thermometer? If the temp is in normal range, then it's the temperature sending unit. Check to make sure this is hooked up. If it is, I'd think about replacing it.

 

Well it seemed like the two heater core hoses got really hot and the one on the top out of the tstat housing started to swell.I found out the heater core was clogged so I tried to flush it but ended up busting it out under the dash.So I bypassed it and no longer have the swelling problem but the temp gauge still aint working.Im heard you can umplug the sending unit and it should go all the way to the hot side?Im going to attempt this in about 2 hours when I get home.I saved this truck from being junked and I have had no problems fixing the things that needed to be fixed untill now.Im ready to get it on the road for hunting season in about 1 month.

 

Thanks for the help. It was the sending unit for the gauge above the starter.

 

That's what this site is here for...I'm glad I could help.