Another heater question for a 1990 truck

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Mythic

Newbie
Joined
Sep 17, 2011
Messages
30
Reaction score
2
Hey everybody, so I am still having issues with my heater. A month or so ago I replaced the radiator and thermostat. I used fail safe thermostat and it never really seemed to function properly, but I was getting some warm air. It never got hot though. A week and a half ago, the belt shredded on me. I replaced it and everything seemed fine. Except that the temp gauge now did not register anything. It just sat all the way to the left. I also now had only very cold air blowing from the heater. So today I replaced the failsafe thermostat with a standard duralast unit. It seemed to take a long time, but the heater finally started blowing really warm air. The temp gauge is now registering. I was pleased. However, as I took it for a test drive I noticed two things. First, whenever stopped, the battery would drop from 14 volts to 12 volts. That is with no radio on, heater on full blast and headlights on. Secondly, the heat eventually diminished. It never got frigid cold like it was before, but it was not not even warm. I got back to the house and popped the hood. Looks like my radiator cap is leaking. I went and got a new one and I am now waiting for the truck to cool down so I can replace that.

Anybody have any input on this? Much appreciated.
 

Mythic

Newbie
Joined
Sep 17, 2011
Messages
30
Reaction score
2
okay, so I put the new radiator cap on. no more leak there. However, now the temp gauge is moving all over the place. It will go from almost to 260 all the way down to alot 100. And still no heat. So just a recap, the radiator is brand new, the radiator cap is brand new, the thermostat is brand new and the fluid is full.

When I had it idling in the driveway after the last test drive, i was just giving it some revs. aslong as I was keeping the rpms up, the heat was there, as soon as I let off the gas, the air got cold again.

Could this be a wter pump issue related to when the belt shredded?

Please, any info at all would be greatly, greatly appreciated.

Thanks.
 
Top