86/87 Heater control problems

[shroom59]

Well sometimes it works and other times it doesnt. I get heat and plenty of that, but sometimes when i hit the fan control nothing happens. Then going down the road it kicks in. There is also an issue with going from defrost to heater, sometimes that isnt working. I can hear the baffles moving but no transfer right away. I looked under the doghouse and seen a vac line running down the right side from the front right corner. Now they disconnected the air conditioning, just cut and plugged the unit. I have a hose and a vac hose which is about 3 and a half feet long beyond the back of the block in leangth.
I wonder if the control is bad or just perhaps a vac line isnt hooked up.
I also have a sensor on the right side of the block next to the exhaust manifolds. Its a one blade with no wiring in sight. I notice my temp guage on the dash doesnt work and beleive this is it. The only available wires i see are a black and grey one comming off the cabling on the front side of the engine right in front of the TBI. Still getting it all put together from the last one who gave up. Great shape this is in, no rust and only 62k on it.
I also have another post going on about the radio harness wiring. It will be labeled 86 RadioWiring Help. Please help me with this one too!