1999 C1500 Suburban Front Heater
 

New Thermostat
New actuators - fresh air, blend door, you name it
Heater hoses in engine bay both hot
NEW AC/heater controller installed today (Brand new AC Delco)
Followed instruction to a T. Disconnected negative battery etc.
New radiator (a month ago)

STILL NO HEAT IN FRONT!!! :devil:

Driving me insane.
R Vin Number - old body style 99
LS version 5.7 350

HELP

Possibly the heater control valve solenoid behind the dryer?

Re: 1999 C1500 Suburban Front Heater
 

I had that problem that ended up being the heatercore,thermostat,and radiator cap

Re: 1999 C1500 Suburban Front Heater
 

This model doesn't a heater control valve. Sounds like the core might be restricted/stopped up. Have you tried back flushing the heater core? If not, remove both heater hoses at the firewall and use a garden hose to flush the core both directions. See if you get any flow or trash out of it.

Re: 1999 C1500 Suburban Front Heater
 

I backflushed a couple of times before finally changing it all out....