Blower motor

[woody62]

The blower motor on our 87 made loud noises and then stopped. No fan at all. We just replaced the fan and still nothing. Check the fuse by the drivers side and fuse it fine. Replaced it asnyway and still no power to the fan motor. Nothing seems to happen at the heater controls.

 

This is a none AC truck so I don't think I have 4 speeds fan. Would the resistor stop the fan from turning? No power? Am I missing a fuse??

 

I put power from the battery directly to the old fan and it made a load noise so I know it is junk.

 

What do you think the problem is?

[woody62]

The blower motor on our 87 made loud noises and then stopped. No fan at all. We just replaced the fan and still nothing. Check the fuse by the drivers side and fuse it fine. Replaced it asnyway and still no power to the fan motor. Nothing seems to happen at the heater controls.

 

This is a none AC truck so I don't think I have 4 speeds fan. Would the resistor stop the fan from turning? No power? Am I missing a fuse??

 

I put power from the battery directly to the old fan and it made a load noise so I know it is junk.

 

What do you think the problem is?

[BLHTAZ]

Yes...the blower resistor would be my first suspect.

[BLHTAZ]

Yes...the blower resistor would be my first suspect.

[Akula69]

:agree: what he said.

[Akula69]

:agree: what he said.

[FxRacing282]

resistors are only for low and medium. if you have no power then check the lines going from the fuse to the switch and then from the switch to the motor

[FxRacing282]

resistors are only for low and medium. if you have no power then check the lines going from the fuse to the switch and then from the switch to the motor

[deziped]

With power direct to it & all you get is a noise, it is probally shot/wore out/junk. m2c.

[deziped]

With power direct to it & all you get is a noise, it is probally shot/wore out/junk. m2c.

[woody62]

I put in a new motor. Still nothng. What is between the fuse box, switch, resistor and motor??? Anything else that could be the problem? Any other fuse? Could the switch on the dash stop it from working??

 

I have power at the fuse box. Fuse is good there.

 

woody

[HOrnbrod]

This is how the circuit flows on HI speed. The 12V output from the fuse goes into pin 8 of the 10-pin connector behind the heater control panel. From there it goes to the Heat Mode select switch, then directly into the blower switch. When in the HI position, it goes to the pin B of the Blower Resistor pack, where it's spliced directly back to pin 6 of the 10-pin connector, then directly to the hot side of the motor. You really should invest in an electrical FSM - it will be your best friend. :D

[BLHTAZ]

I just posted a link to a .PDF of the electrical manual in the DIY forum today...go check it out ;)

 

When mine wouldn't work at all, the resistor was the culprit. When I tried to take it out...it fell out in pieces as the inside had rusted completely apart.

 

I seem to have missed that part about direct wiring it so yes, if you have direct wired the motor and you get nothing then it's time for a motor...maybe motor & resistor as the motor failure has been known to cause the resistor to go bad too.

[woody62]

We now have replaced the motor, resister and we have blower working. Success! But now we have lost heat. We have a new heater core we put in this summer and it was working before we pulled the blower.

 

We think the switch is not working correctly. How does the heater valve get turn on? Vacuum activated? Since it is winter can we manual make sure the valve for heat is always on?

 

thanks,

woody

[Pete M]

I seem to remember reading that the newer XJs don't even have that vacuum actuated switch.

[BLHTAZ]

I seem to remember reading that the newer XJs don't even have that vacuum actuated switch.

That is correct...they don't use a valve, but simply have fluid flowing through the heater core all the time :cheers: .

 

Yes, the valve is vacuum actuated and you can force it open and tie it with a zip tie or something like that. If it is bad and you want to replace it, I have one that is only a few months old that I would sell you. ;)

[woody62]

Thanks to Pat, we figured out that the problem was the heater box flipper door control. It would not open/close correctly.

 

We now have taken the vacuum control out and run hoses direct and have the cable to the flipper door totally off. It is setup to have heat 24/7 now. Works great!! will have to fix for summer but perfect for this winter!!!

 

Thanks guys.

 

woodt

[jtdesigns]

And on a side note about the vacuum controlled valve on the heater hose.

When there is no vac to it, it defaults to always open, or flowing of coolant.

[Motion Offroad]

That is correct...they don't use a valve, but simply have fluid flowing through the heater core all the time :cheers:

This is only for 1997 and up I believe. The Renix era used one style, than the HO from '91-'96 used another style. Than in 1997 they did away with them completely.

[carnuck]

If you can't get the controls to work right, make sure the vacuum bottle hoses weren't messed up during the fan replacement. Another prob where you only get defrost and no heat is the vacuum motor above the gas pedal gets the hose knocked off when someone's foot goes too high!