Heater help!

[79Betty]

Well i need help. Surprise surprise right? On my 77 k10, i put a new blower motor and fan blade (metal) but i have nothing through the vents. I have attached pic of my outside wiring where i think the problem is. Also my heater core hoses are only... Lukewarm... Thought they were supposed to get hot as hell?

[jlk]

It appears you don't have vacuum connected to your amplifier on the firewall. The black round thing in the front left of your picture. That could keep your blend door from opening. Warm, not hot heater hoses sounds like a bad thermostat.

[79Betty]

I'll get a new thermostat. Little assurance. It has a vacuum hose goin to the ball thing it goes over the box. Think it goes to the back. But my blower doesn't turn on at all :/

[rs74]

So are you not getting power to the blower motor? Also you might want to flush the heater core while you are in there and change the thermostat as you said.

[jlk]

See the thread here titled "Heater Blower" about possible causes why your blower motor isn't working. The black round vacuum reservoir only appears to have one vacuum hose attached to it. It needs a vacuum hose from the carb to it then another hose goes inside the cab to the heater control.

[79Betty]

Well small update. I put i a bew thermostat 195 since it's getting cold this timma year. Hoses only get kinda warm not hot :/ same cab before did this too

[Hertzdaddy]

Its possible, though not probable, that the heater core is nearly completely clogged so that little to no fluid is running through it.

Also, did you check the blower fuse?

[79Betty]

Will check fuse tonight. Other than this n my driveshaft i'm ready to rock. Where does the big red wire go?

[Billy81]

Looks like the wire that goes down to your starter but i can't really tell but that would be my guess.

[79Betty]

So it comes out of the firewall by the ac and heater wires to the starter? Seems odd. Does the vacuum line go to the front port or back port on the ball thing?

[Billy81]

Well i can't tell where it's coming from in your picture but the connector on the bottom and thickness of wire looks like the one that goes to the starter.

[83GMCK2500]

Red wire might be the one that runs across the firewall to the junction block.

[79Betty]

Think i'll look behind the heater box tonight. Surprisingly ye heater core doesn't leak or anything. What about all the green wires? Can i cut-n-tuck them? I won't reinstall the ac.

[Hertzdaddy]

Honestly, all of that wiring is a little scary looking. You might want to get a wiring diagram and clean up some of those wires. Its probably not a good idea for us to be guessing what wires are what. That could lead to some serious problems if wrong.

[79Betty]

It starts n runs string n fine. All lights work just the heater >:/ aggrivating! I'll look tonight for one n i'ma try n get ridda as much as possible for simplicity

[Phillip Pennartz]

is there a vacuum controlled valve for hot water to the heater core? if so, bypass it and see if it gets hotter. also the heater hoses have to be hooked up where the return hose goes to the water pump and the supply hose to core comes from intake. I think thats the way it goes.

[Sodell]

Fist thing to do would be to check the power at the blower and go from there. That box the wire to the blower motor comes out of is the relay switch, that would be the next thing. Sometimes you can hit the relay switch and get it going for a bit. There is also a resister but high power is not affected by this.

Get the blower working and then go from there.

[Sodell]

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[79Betty]

So the red goes to the other side (left) of the junction block... And green goes to... Evap control switch. Do i need the evap switch for the heater or no?

[Sodell]

Not sure you need that if you are not using your AC. Did you check the power to the motor?

[79Betty]

I will tonight after work. i'll run the red wire over to the junction n see how it all works. But even after a new thermostat i only get lukewarm hoses. It's a 195, i'm afraid to put anything higher in.

[rs74]

Are you driving this truck trying to get it up to temp or just letting it set and idle. I have had a couple of vehicles that wouldn't get very warm until they were driven. It should still be getting some temps going though.

[motornut]

lower right of pic the (brown 50),dosn't that go up in the dash with the radio wires?
if you can test it, to run ok ,from the batt
I'd check the blower coils

[79Betty]

Idk if it is or not. UPDATE: Plugged in the vac hose to the FRONT of the ball and the back going into the cab somewhere, also put the red wire onto the junction block and no difference
Updated pic showing more green wires unpluged what is that 2 pronged thing on the bottom right of the box? Needed?

[Sodell]

Originally Posted by motornut

lower right of pic the (brown 50),dosn't that go up in the dash with the radio wires?
if you can test it, to run ok ,from the batt
I'd check the blower coils

I thought that was the resistor?