Have A 93 K1500 Fan Works But The Heater Doesn't Get Hot. Its Lukewarm. Back Flushed The Heater Core And Hoses. Any Ideas Why It Doesnt Get Hot?

Does your engine get up to operating temp? Have you checked your thermostat? Just for starters.

I Put A Hi-po Chip In And A 160* Thermostat. The Engine Has Never Got Above 120* To 130*, Even When I Had The Factory Rated Thermostat.

Interesting. I thought standard operating temp was up around 190.

Its Been Like That Since I Bought The Truck About 6 Months Ago.maybe A Inaccurate Gauge? Thanks To All. All Comments Greatly Appreciated.

Check this with a manual guage or a thermometer in the radiator. My 88 normally runs at about 180*-200*. I would also run a can of radiator flush in it and change the antifreeze.

I had this problem with my 90 1500. Disconected the heater hoses at the core and blew out the core with Air. Had blockage and heat was restored.