Mechanics

TARUS HEAT/AIR NOT WORKING. UNIQUE PROBLEM

1998 Ford Taurus

Electrical problem
1998 Ford Taurus 6 cyl Two Wheel Drive Automatic

This summer my brother in laws Tarus air conditioner quit. To make a long story short after checking just about everything, I found a relay in the engine compartment was bad. It looked like the relay had some burn markings on one of the terminals. He replaced the relay and it worked for about a few weeks. Also at this time the air only worked don high so he drove around constantly with the air on high. (I am sure this was probably due to the blower motor resistor.).

Anyway now it does not work again. I replaced the relay and still nothing. I have no voltage to the harness that plugs into the blower motor. I took the blower motor out and connected it to a batters. When I touched the wires at the batter it sparked pretty bright and started spinning. So I assume the blower motor is ok.

There is no voltage at the harness that plugs into the resistor. There is not voltage to any of the four wires going to the fan control switch. (I am not sure if there is supposed ot be or not?)

One thing I noticed is when I was origionally checking around with a tester, where this relay pluged into the power distribution panel, I origionally had voltage on two of the places the relay plugs in, now I only have one.

I dont have anything that explains what the fuses and relays go to, but I believe I tested everythign in the fuse panel and it was ok.

What can I do to figure this out, he has no heat and just got layed off so I am trying to help him and his young son.

Can anyone explain to me what the wires to the relay go to and where I can go from here?
Avatar
Stryped
October 19, 2008.



Below is your AC/Heater EWD


http://www.2carpros.com/forum/automotive_pictures/12900_b1_4.jpg



http://www.2carpros.com/forum/automotive_pictures/12900_b2_4.jpg



http://www.2carpros.com/forum/automotive_pictures/12900_b3_4.jpg


Rasmataz
Oct 19, 2008.
Thanks so much! Where do I go from here? What would have caused the short/melted relay terminal? I have read that water leakage in the passanger compartment is common in these cars. Could that have somehow shorted out the blower motor? I took the motor out and hooke dit up to a 12 volt batter. It spun but it really sparked when I hooked it up to the terminal. I only ran it for a second.

Tiny
Stryped
Oct 19, 2008.
At the blower motor the pink and white is your power and the orange and blue is the ground side-

Melted/shorted relay could be caused by an overload too-What relay are you refering to?

Rasmataz
Oct 19, 2008.
The relay for the plower motor in the power distribution block. The plastic in the power distribution panel was melted where the relay pluged in and it has blown about two relays.

I hooked the blower motor firectly up to a battery and got a heck of a spark when I touched the wire to a battery post but the motor did spin. The spark almost looked like a weldign spark it was so bright. (It is possible I had the power and ground backwards).

Could the motor work but be causing some sort of overload?

You dont have a description of the fuse locations do you? My brother in law does not have the manual to the car and the top of the fuse cover is missing.

Thanks so much for helping me help someone else out!

Tiny
Stryped
Oct 20, 2008.
Fuse no.11 and 13 see below


http://www.2carpros.com/forum/automotive_pictures/12900_fuse_4.jpg


Rasmataz
Oct 20, 2008.
Thanks so much! I guess the highligthed ones are to the blower motor. I guess these are the two fuses that go to the 2 " hot" terminals at the blower relay under the hood? I swore I checked all the fuses but I will again.

My guess is the blower motor works but is drawing too much load and that is what is frying everything. Is there a way to check that with a voltmeter?

Tiny
Stryped
Oct 20, 2008.
Do a voltage drop test at the pink and white wire on the blower motor

Rasmataz
Oct 20, 2008.
Sorry for the ignorance, how do I do that? Tap into the wire and see if the voltage drops while the unit is on high?

Tiny
Stryped
Oct 20, 2008.
Yes-check every position from low-high-Hence the resistor will be dropping voltage as you increase the speed

Rasmataz
Oct 20, 2008.
Is there a fuseable link in this system that could have blown causing me not to get voltage and one of the terminals of the blower relay in the engine compartment?

Tiny
Stryped
Oct 21, 2008.
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