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Nov 30, 2006 | 12:07 PM

Budderamos

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Hello, Have an F150 1999 basic work truck with no frills (power windows, locks, etc) except 4X4. Has the full bed (love it!)

Just beginning to get into some maint issues:

1) Feeling play in the drive train: Looking for some basic home diagnostics here...

2) Just discovered the heater not working. Start with the diverter valve controled by the in-dash "Blue to Red" sweeping control? Is this vacuum controlled? Where to start looking?

Thanks! Rick

Nov 30, 2006 | 11:24 PM

Racerguy

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From: BC, Canada

Welcome to the forum Rick

When do you feel the play in the driveline? Have you checked the U-joints?
Does the heater blower work and it just doesn't blow warm air or?
A fairly common problem with a lack of warm air is the heater **** cracks and doesn't turn the shaft on the control.

Dec 1, 2006 | 10:10 AM

Wilber15

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From: Duluth, MN

Do you feel it from a stop? Could be U-joints going bad. You may need to remove the driveshaft and twist the u-joints to feel for excessive drag or binding. You can't always feel the play with the shaft still on the truck. Also, the slip-yokes on fords do tend to bind occasionally. When you have the driveshaft out checking U-joints, squirt a little Teflon Grease in the end of the drive shaft yoke that fits into the transfer case. This should cure the binding.

Dec 1, 2006 | 10:16 AM

Wilber15

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I'm looking at the schematic for your heater blend door, and it looks to be electrically operated. Looks to be run by a 15A fuse in the Central Junction Box... I'm looking at the schematics for a 5.4L seein as u didn't state your engine size. But you should have 12V at the LB/PK wire at the motor connecting harness.

Dec 1, 2006 | 01:54 PM

Budderamos

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Thought I checked the u=joints but will check that again. Play is typically felt going from coasting to acceleration. Feels like "the play" in the drive train is catching up and then "bumps"
Engine is 4.6L. Checked all fuses in cab junction box. Also took a look at power distribution junction fuse box in engine compartment. No fuses blown.

Dec 1, 2006 | 11:31 PM

Racerguy

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From: BC, Canada

The "bump" you feel in the drivetrain is quite likely the driveshaft slip yoke binding on the output shaft of the transfer case. Ford sells special Teflon grease for lubing the splines inside the yoke. That will usually get rid of the bump unless the yoke is worn in which case you'd probably end up replacing it.
If the heater blower motor doesn't work you should start by checking for power and ground at the motor. If you have 12V and ground at the motor then the motor is the problem. You should have 12V at the brown/yellow wire at the motor. This wire gets its power from the blower motor relay under the middle of the dash. The relay is in with the flasher relay so turn on the signal lights and listen for the ticking to find the relays. The orange/black wire is ground from the blower motor resistor.

Dec 4, 2006 | 05:29 PM

Budderamos

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Thanks for the comment on the drivetrain - will follow up.

The heater blower is fine. Problem is no heat when heater control **** is full to the right. Normally you can hear some kind of actuator moving inside the dash when the control **** is turned from "blue" to "red". At this time I don't hear anything. Wilbur15 mentioned this being electically controlled. Didn't find any fuses out. Still troubleshooting.