New to the forum with a couple ?'s and advice

[Project86]

What's up guys. Finally decides to register on here
I'll fill you guys in on the scoop.
First time chevy owner and I'm loving it. I originally bought an 81 c10 swb. It needed a lot of TLC. I ended up buying an 86 swb for cheap and eventually did a cab and bed swap. And after that I bought a 350 and beefed it up a little. So I'm in the process now to getting it ready to be on the road for a good bit but I'm running into small issues that have me scratching my head.

First off, it's getting to be cold here in south MS. SO HEATER IS MUST!!!
Anyways the heater was working before cab swap. I did remove all ac components since a lot was faulty but I kept the box and very thing on the firewall.
I can turn the heater and blower on by the switch but nothing happens at all. All the connections are wired up as they were before. All fuses are good so I'm going on a bad blower motor or something.

Secondly, couple days ago I accidentally bumped the starter over while it was running.
Now when it's cranked up and running there is a hollow clunking sound coming from the transmission and it's definitely a rotational sound. Kind I like you tap a wrench on the bell housing.
-I'm running a th350 with a 1500 stall converter. I do have a small pan leak and I have to keep an eye on my trans fluid, however the trucks shifts crisp and hard just like it has before with no issues or slipping


Hopefully I can get a discussion started and we call all help diagnose my issues

Thanks everyone in advance!

[Ski-me]

Check your heater relay that should be mounted on the heater box (in engine compartment). Make sure it's sending power to the motor. Also, be sure you have grounds good and solid. There should be one for the motor (also near the relay in the engine compartment).

[Project86]

Thanks for the reply. Actually just went outside to check for continuity to the motor. I have power to the terminals. Power going into the relay. Power is not coming from the relay to the motor. Believe the wire is purple, thick gauge.
However I did try to run a jumper wire to the motor and nothing happened. The relay did click when I unplugged the harness and plugged it back in.

[meatwagon83]

wait, did you say its getting cold in south mississippi? what is it? 70 degrees?

[Project86]

It's comfortable at the moment but the heater still need to be working haha

[meatwagon83]

i feel ya! its starting to frost here, and my defroster doesnt work, i hope it isnt the blend door, i need to get off my lazy ass and fix it

[Project86]

That ain't no good!!!! Hopefully you can get it fixed

[Ski-me]

One of those wires only works when the fan switch is on high.....otherwise no juice. Might just verify.

[Ski-me]

Oh and its snowing here now....

[Tx Firefighter]

If the blower motor worked before and now it won't run even with a straight jumper wire to it, I'd bet your ground wire is missing. There should be a little ground wire under one of the blower motor screws.

[Project86]

Ground wire is there but I am going to clean it up where it grounded to. And ski are you sayin that if I switch the fan on high, a wire will show power if I test it? If I clean the ground, recheck fuses and see it has power could I look at the climate control for something?

[Project86]

I will go ahead and say that the evaporator core? Is out of it. I pulled it alon with ac components.

[Tx Firefighter]

Originally Posted by Project86

Ground wire is there but I am going to clean it up where it grounded to. And ski are you sayin that if I switch the fan on high, a wire will show power if I test it? If I clean the ground, recheck fuses and see it has power could I look at the climate control for something?

No.

Until you get the blower motor working, you're wasting your time looking at the control.

It's as simple as that. If you hot wire the fan and it doesn't run, you have a fan issue first and foremost. Occam's Razor. Always start with the simplest solution and work upwards in complexity. Get the fan working first.

[Project86]

Ok well since you said check grounds I'll do that just to make sure.

[Ski-me]

Originally Posted by Tx Firefighter

No.

Until you get the blower motor working, you're wasting your time looking at the control.

It's as simple as that. If you hot wire the fan and it doesn't run, you have a fan issue first and foremost. Occam's Razor. Always start with the simplest solution and work upwards in complexity. Get the fan working first.

^^^^^ this. Get the fan working first and then move onto relay/controls. You can replace the fan motor pretty easily. AutoZone has them for maybe $30 or $40 bucks. Should be able to test it pretty easily with a 12v source.

[Project86]

Originally Posted by Ski-me

^^^^^ this. Get the fan working first and then move onto relay/controls. You can replace the fan motor pretty easily. AutoZone has them for maybe $30 or $40 bucks. Should be able to test it pretty easily with a 12v source.

I feel as though I may be slapping my face later. But could I remove the motor and try to test it separately? Like you would do with a starter? That way I could rule out the motor if anything miraculously happens.

[meatwagon83]

Yes, you should be able to test the fan with a car battery

[Project86]

Quick update. Bench tested the blower motor and it works. Cleaned the grounds really good and it works as well. Relay seems to be good as I took it from the metal cover and watched it engage and listened to it.

One issue I do see, motor only works on the HI setting. Works on vent, ac, heat, def etc and turns off when you turn it off. The doors don't seem to be working to channel the flow. Only comes from the floor.

Any ideas? And thank to everyone for the ideas.

One step at a time

[Ski-me]

Originally Posted by Project86

Quick update. Bench tested the blower motor and it works. Cleaned the grounds really good and it works as well. Relay seems to be good as I took it from the metal cover and watched it engage and listened to it.

One issue I do see, motor only works on the HI setting. Works on vent, ac, heat, def etc and turns off when you turn it off. The doors don't seem to be working to channel the flow. Only comes from the floor.

Any ideas? And thank to everyone for the ideas.

One step at a time

Because the relay only delivers on high, I would suspect a faulty relay. Worth a shot for $8 at Autozone.

If it's only blowing on the floor, most likely your blending door tab is broken. VERY common! And to boot, it's only a $2 part but you have to find one (and pay $5 for shipping!)

http://www.classicparts.com/1983-87-...ctinfo/68-248/

[Project86]

Thanks for the quick info. I'll look into a new relay and see if I can crawl under the dash to see if the door is working

[Project86]

So I noticed the vent controls have vacuum hoses. Any way to troubleshoot those

[donut]

Start at the firewall, find the vacuum line. (engine side) Got vacuum?
On my '86, the line goes through the firewall next to the AC box. (actually plugs into a nipple that passes through the firewall.)

Mine the engine compartment lines were rotted off. one of the reasons mine didn't switch.

[Project86]

Originally Posted by donut

Start at the firewall, find the vacuum line. (engine side) Got vacuum?
On my '86, the line goes through the firewall next to the AC box. (actually plugs into a nipple that passes through the firewall.)

Mine the engine compartment lines were rotted off. one of the reasons mine didn't switch.

UH-oh.......

i see a line that is located on the right of the a/c box but its cut off and has roughly 6" sticking past the firewall....

where does the vacuum line run to??

[donut]

Not an uh-oh. I'd much rather chase vacuum leaks on this side rather than under the dash.
On my truck (yours may vary), the line ran to a vacuum ''ball", about the size of a softball, on the drivers side (I think location changes on the year.) Then a line ran from that to the engine. I think mine ran to a vacuum "tree" behind the carb.

Basically you just need to get a vacuum source to the firewall pass through. Hopefully, it'll all magically work after that. If not, your good up to a point at least.

[Ski-me]

Yea, just start replacing vacuum lines as much as you can. Pick up some at a autoparts store and then replace as many as you can/find. I'm sure they are pretty old by now.

Do you hear any air/vacuum noises when you move your HVAC selector around? Like A/C to Norm to Heater to Def? If you don't hear any air type sounds then you need to get your vacuum lines fixed. This will also move your blending door once fixed. Probably need to fix both the vacuum lines and also the blending door tab.