86 monte ss 454

[Nathan454]

Having a little issue with the blower motor now it was only blowing out the defrost vents,but stopped working all together two days ago,the issue I'm having is that the engine is now a big block,I'm assuming that I need to hook up a vacume line to one of the many ports on the carb?inorder to be able to have control settings for the vents but I'm not real sure where to hook it,I haven't found any hard plastic pink lines,also how can I get to the blower motor leads to test if the blower is bad?

 

[Texas82GP]

On the blower motor, an easy way to test it is to hook it up directly to 12V like with a battery charger. The wiring for the blower motor is all right there under the hood so it is accessible for testing. The blower motor resistor is right there in the top of the HVAC case. There is a four wire connector in the HVAC harness above or behind the passenger valve cover. It can be prone to burning up so give it a visual inspection. Here's a wiring diagram on the blower circuit.....

 

[Texas82GP]

The doors for the HVAC system are vacuum controlled. When there is no vacuum the default position is defrost. From the factory there are two small hard vacuum lines that come through the firewall under the hvac case. The pink or purple one supplies vacuum to the HVAC mode switch. It connects first to a small plastic sphere (still available new from Dorman) and then a line runs from the sphere to manifold vacuum. The other line is green or grey and connects to an inline heater control valve on one of the heater hoses, which blocks the flow of hot water through the heater core when you are running A/C.

Maybe look under the HVAC case to see if either line are still coming through the firewall. If not, you will have to run a new line from where they are chopped off under the dash through the firewall. Might be a little bit of a chore but doable.

 

[Bar50]

You may also try tapping on the high speed blower relay. They stick.

 

[Nathan454]

The doors for the HVAC system are vacuum controlled. When there is no vacuum the default position is defrost. From the factory there are two small hard vacuum lines that come through the firewall under the hvac case. The pink or purple one supplies vacuum to the HVAC mode switch. It connects first to a small plastic sphere (still available new from Dorman) and then a line runs from the sphere to manifold vacuum. The other line is green or grey and connects to an inline heater control valve on one of the heater hoses, which blocks the flow of hot water through the heater core when you are running A/C.

Maybe look under the HVAC case to see if either line are still coming through the firewall. If not, you will have to run a new line from where they are chopped off under the dash through the firewall. Might be a little bit of a chore but doable.

Ok I found the hard plastic lines coming through the firewall one is purple the other is grey/ white ,right now the Grey one is going to the manifold the purple one is not hooked up,I no longer have the little round sphere can I just hook up the purple line direct to intake or do I have to have the sphere, then I need to run the grey on to the inline connection on the heater hose

 

[Texas82GP]

Ok I found the hard plastic lines coming through the firewall one is purple the other is grey/ white ,right now the Grey one is going to the manifold the purple one is not hooked up,I no longer have the little round sphere can I just hook up the purple line direct to intake or do I have to have the sphere, then I need to run the grey on to the inline connection on the heater hose

For now you can hook up the purple line directly to manifold vacuum. The purpose of the sphere is to store vacuum for times of low engine vacuum like wide open throttle. Without the sphere, the vents will switch back to defrost as they run out of vacuum when you are hard on the gas. The sphere is cheap. Here is a link.....
https://www.amazon.com/dp/B000COB8FA/?tag=gbody-20

The grey/white vacuum line needs to come off of manifold vacuum and connect to your heater control valve on your heater hose near the firewall.

 

[TURNA]

very nice ride!

 

[Nathan454]

For now you can hook up the purple line directly to manifold vacuum. The purpose of the sphere is to store vacuum for times of low engine vacuum like wide open throttle. Without the sphere, the vents will switch back to defrost as they run out of vacuum when you are hard on the gas. The sphere is cheap. Here is a link.....
https://www.amazon.com/dp/B000COB8FA/?tag=gbody-20

The grey/white vacuum line needs to come off of manifold vacuum and connect to your heater control valve on your heater hose near the firewall.

Ok so I hooked up the vacuum lines properly, and got everything working good on the hvac,but for some reason I keep blowing the heater fuse under the dash as soon as I turn everything on I jumped the blower motor to test it so I know it works but can't figure out why the fuse keeps popping any help will be appreciated

 

[Opie Knievel]

That is a beautiful SS you have. I love that you have the big block in there and still have A/C.

It blows the fuse when you move the lever from off to one of the vent settings or when you turn the blower up past the lowest speeds?

 

[Texas82GP]

Give us some more detail on when it blows the fuse and what causes it.