Heater help!
 

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?

Re: Heater help!
 

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.

Re: Heater help!
 

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 :/

Re: Heater help!
 

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.

Re: Heater help!
 

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.

Re: Heater help!
 

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 :(

Re: Heater help!
 

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?

Re: Heater help!
 

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

Re: Heater help!
 

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

Re: Heater help!
 

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?

Re: Heater help!
 

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.

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

Re: Heater help!
 

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.

Re: Heater help!
 

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.

Re: Heater help!
 

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

Re: Heater help!
 

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.

Re: Heater help!
 

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.

Re: Heater help!
 

[IMG]http://i1344.photobucket.com/albums/...psae8ae9ab.gif[/IMG]

Re: Heater help!
 

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?

Re: Heater help!
 

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

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I will tonight after work. :metal: 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.

Re: Heater help!
 

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.

Re: Heater help!
 

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

Re: Heater help!
 

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?

Re: Heater help!
 

I thought that was the resistor?

Re: Heater help!
 

in the B&W picture, the resistors/coils are shown under the blower motor.
with or without the AC you have them,different ones,but you have them

Re: Heater help!
 

Yea, I was trying not confuse 79, that is the resistor that he is calling the blower coils. If that resistor (blower coil) is not working you will still get high fan.

Re: Heater help!
 

Ithink i still get fan because last night i could feel wind coming out of the side of it, but nothing through the vents so i think that'llbe next issue. I couldn't see last night to confirm it though :/

Re: Heater help!
 

I only see a purple hot wire, where is the ground wire?
Blower motor will not operated with out being grounded.

Attachment 1172670

Desert

Re: Heater help!
 

that would do it
my non-ACs in my 78 and both 79s dont have grounds,those outside boxes are metal,my 87,88,89,with AC do have them but cause those are fiber boxes
can almost make out the spot too,like my 89

Re: Heater help!
 

Sorry i can't edit pic's everyone but can only take. The black wire from the resistor? Has purple, blue red wires. I can take it and ground it to a fender bolt hole and hear it "Click" like it kicking on. But still can't tell if the motor is turning. Also i have hot hoses now!! Found that out the hard way lol i mean this wire.

Re: Heater help!
 

throw/wedge a couple of Kleenex/TP on the exits?

Re: Heater help!
 

The click you hear is the relay making contact and not the motor. Go ahead and connect that to the firewall with a screw. A clean, new screw that way you will have a good ground. Also from that screw attach another ring terminal with an ##12 wire crimped to it with another smaller ring terminal on the other end of that wire. Then remove one of the mounting screws from your blower motor and rough up and sand the paint off under it. Then replace the screw with the ring terminal in it. The ring terminal should be making a good ground the the blower motor through the roughed paint. This should solve your problem.

Re: Heater help!
 

And i will do just that. The motor spins, but i found out there are 2 blower motor wheels. One for HD heater and one for non HD. I have a HD motor with non HD wheel which won't work because of the offset. The wheel was rubbing the motor backing plate which is why it wasn't spinning. New one will be here tuesday! Now to figure out why the blend door won't open

Re: Heater help!
 

Not sure how your heater controls are compared to my 85 but my blend door would not operate either. Tore into it and found that the white plastic clip that holds the rod in the picture was missing. Everything else was operating except it wasn't hooked to the blend door due to missing clip.

You said you got hot hoses now. What changed? I am going to have to go back and read it again. Maybe I missed something.

Re: Heater help!
 

I did put a new thermostat in it. I'ma dig into it today after breakfast.

Re: Heater help!
 

Update . Sorry guysi've been busy with work n weather is not cooperating. I got my blowe motor to run. Check. Now i still can't get the blend door moving. What if the vacuum canister ball on firewall is clogged? Could this happen? I have a vac line going from my carb to it. When i unplugged it to move it for a sec it depressurized.

Re: Heater help!
 

Easy, but messy, way to check the heater core is disconnect the two black hoses and hook a water hose up to one and see what kind of flow you have coming out. Don't know how crap gets in there, but my son had an s-10. When I hooked the hose up, sludge came out...after that, he had hot air.

As for the blend door not moving. You can get a hand vac (brake bleeder) and see if you can pull a vac. If the actator on the back isn't working, check out this thread. It helped me replace mine. And while you're at it, you've got access to change the heater core too. Kinda one of those, well, since it's apart, might as well put in a new one.

http://67-72chevytrucks.com/vboard/s...d.php?t=460942

Re: Heater help!
 

From my 81 book.....

Re: Heater help!
 

must be close,if not the same?