Allright I need help please.

I have a 99 Expedition Eddie Bauer 5.4 4x4 383k miles.

All of a sudden the front blower stopped working on any setting. Read through the forums and decided I needed to replace the Blower Motor Resistor. While I was in there, I wanted to avoid going back in, and replaced the blower also. Plugged everything in, and ZIP, nothing, nada!

Swapped relays around under the drivers side (relay 5 for 4, they apparently are the same). Swapped 2 for 1 and still ZIP! Checked all of the fuses (there is a 40) under the hood that relate to the front blower. Anyone have an idea of how to test the plug (3 wires) going into the resistor? I guess the last thing to replace is the EATC head.

 

If you can solder, open up the EATC unit and often you'll find that the blower output (terminal 17, orange wire) copper on the PB board is burnt. Solder a jumper wire across the burnt section and the blower will work again.

 

Allright, I'm looking to see if that is the case... Thanks for the suggestion.

 

Just looked, all the connections are good, all the wires from the fan rheostat including the orange brown wire, are in very good shape.

 

Grab your meter and check for power on both blower motor connection pins (leave motor plugged in) with the system turned on. What are the two voltage readings?

The wire that alloro referred is an orange wire that runs from pin 17 of the EATC to the low side of the blower relay. If it's indeedburned up, the blower will never operate.

YOur vehicle doesn't have a resistor pack, it uses an EATC-controlled blower Control Module to operate the blower, assuming that the blower motor relay is operating correctly.

 

So I checked the voltage after the new resistor I installed from Autozone, which sits under the glove compartment and has 1 connector coming in and 1 going out to the blower fan.

Voltage red to vehicle ground = none detected
Voltage black to vehicle found = none detected

EATC unit on with vacuum sounds at the selection of different modes. Fan selected high (and every other position also).

So do I understand this correctly that I solder a jumper wire from the yellow/brown wire that plugs into block 1 (which goes to the round fan control) the other end is (flat 5 pins) to Pin 17 which is right behind the black male plug on the logic board where the 2 plugs to the vehicle plug in.

I hope this makes sense...
Bill

 

I'm fascinated - how in the world do you guys know all this?

 

We all took a correspondence course.

 

I mean inside of the EATC unit. Trace the circuit starting at the #17 pin the orange wire connects to, and continue to follow it onto the copper clad PC board inside the EATC unit. You could also first test this orange wire for power when the blower is supposed to be on. If this wire is without power the problem is inside the EATC unit, if the wire has power the problem is not with the EATC unit.

 

Hopefully this will make sense. I started the truck, placed the AC on MAX, opened up the EATC unit again. Placed the fan on high.

Tested with my voltmeter on 20v black to the #17 dot, and red on the flat rotary connector to the fan rheostat. Voltage 5v.

 

I traced the orange printing on the logic board to a resistor. Tested the both sides of the resistor and there is no voltage. It appears to be resistor D9. I would guess it is probably best to just order a new (used) EATC.

Bill

 

Wait a minute.

If you have an EATC, you have a BCM, not a resisitor module. If you have a manual control, then you have a resistor pack.

Try doing it the right way: Black lead to ground and red lead to pin 17. Unless directed otherwise, always put the black lead to ground when making voltage checks.

Been fixing electronics stuff for 35 years... This is just another application of those accumulated repair jobs. Having the Ford service docs also helps.

 

I did it that way first. The voltage was 0.00 so obviously I tried to find voltage somewhere else as well as any indication of a break in the orange die. The connector pin looked a little suspicious. I do have the EATC (Automatic Control). The replaced pack was at autozone: Duralast/A/C Heater Blower Motor Resistor
Part Number: JA1704.

I have also replaced the blower motor with a new one. Found a used EATC for 90.00 with a 30 day return policy. With any luck, that will fix it.

Thanks so much for all your help, you all are the best!
Bill

 

Fuse #105 under the hood has power to ground on both sides of it, correct? Don't just do a visual, you have to test it with a meter. Sometimes fuses are good but do not make a connection.