Low temp and cold heater?

Okay so I noticed that my 87 B2000 never really gets hot on the temp gauge, it might move a 1/8th inch off of the cold bar on a mild day... Well it finally got cold enough in Texas to use my heater and found out that my heater blows cool air, it has some heat to it but never gets hot. Anyone, know what it might be? Im thinking the previous owner may have taken the thermostat out of it or it might be stuck open. Any ideas where to start? Again, Im going through this truck trying to fix it without taking it somewhere and get overcharged for a fix. Hope someone might have a clue.

Thanks in advance, Jason.

Sounds like you are right on the money. I would drain your coolant and pop that T-stat out and replace it. I will say that the cool running is a rare thing for these chronic over heaters. You can find these B trucks all day long with cracked heads or blown head gaskets from over heating. Good for us that like to keep them on the road and bad for those who don't know how to fix them. -Ed

missing or stuck open T stat a very easy fix on these trucks

where exavtly is the t stat

okay Im adding it to the list... got to rebuild the frontend this week and then conquer the t-stat.... WOW it never ends.

follow the upper rad hose to the engine, that hose hooks to the theremostat housing. take out those two bolts holding the housing on, and swap out the thermostat. Just be sure to clean the gasket surface, and use a new gasket.