Heater not blowing, help


Tracy0821
11-29-2006, 07:05 PM
I have a heater problem. When I turn my heat on I get nothing at all. Yesterday I got nothing for 20 minutes of driving and I turned it off and on. Then it turned on. Well today it was off again. I played with the buttons and turned it off and on. Its still not on. Nothing. What could this be. I have a ford taurus 2003

shorod
11-29-2006, 10:00 PM
Welcome to the forum!

Does your 2003 Taurus have the electronic climate control, or the manual controls?

When you say you get nothing when you turn the heater on, do you mean the blower fan doesn't blow any air out, or it still blows, it's just not heated air?

It sounds like a bad connection, either electrical or vacuum depending on your answers to the above questions.

-Rod

MyTaurus8AChevy
11-29-2006, 11:45 PM
Also, if it's the auto climate control version, then what temperature do you have it set at?

Tracy0821
11-30-2006, 07:43 PM
Manual controls. It doesnt blow any air out. Today it was on for an hour. I stopped the car went in to a store and came out to find it wasnt working again.
Welcome to the forum!

Does your 2003 Taurus have the electronic climate control, or the manual controls?

When you say you get nothing when you turn the heater on, do you mean the blower fan doesn't blow any air out, or it still blows, it's just not heated air?

It sounds like a bad connection, either electrical or vacuum depending on your answers to the above questions.

-Rod

MyTaurus8AChevy
11-30-2006, 08:31 PM
I would first look at the ignition switch. If the blk/lt grn wire (ign 2) doesn't get any power then the heater will not work. You could double check this by finding what else is on the ign 2 circuit and seeing if those things stop working too. Could also be a bad relay or corrosion at one of its contacts.

shorod
11-30-2006, 10:35 PM
Does the blower motor work on high speed reliably?

I'd suggest you start by looking at the connectors for the blower motor resistor block. This block limits the amount of current to the blower motor, thus controlling the speed. The "excess" current generates heat, and the connector has a large amount of current flowing anytime the blower motor is running. Even a slightly corroded or loose connection can cause a lot of heat to be generated by the bad connection, and that can cause the connector to melt eventually.

If you have a loose connection at the resistor connection, it may heat enough after 20 or so minutes to open and hence the blower motor stops working. If this is the case, you will want to correct it before the connector melts.

-Rod

jrngmn
12-02-2006, 03:13 PM
I have the same problem, where is the blower motor resistor block located?

MyTaurus8AChevy
12-02-2006, 04:15 PM
Tracy according to the service manual it says you should check these things:


Open/short circuit (includes corroded fuse)
Blower motor going bad
Blower motor speed control
Function switch
Blower motor relay


You could try cleaning the switch(s) listed above and all associated fuses and relays. Next I would test for power at the motor and work your way back in the circuit. The relay could also be dirty/corroded inside. You'd have to disassemble it if it's dirty. If the coil section is bad you'll need to replace it. They didn't mention it in the service manual but it could also be a bad ground at the relay and/or the motor. If the motor isn't getting any voltage (and the ground is good) then you'll need to do resistance checks with a voltmeter.


where is the blower motor resistor block located?
Ordinarily you'd want to start a new thread :wink: But since you're here already what year car, and which heater system do you have? If it's the 'Auto' climate control system then you can simply put it in self diagnosis mode and it will tell what's wrong :grinyes:

jrngmn
12-02-2006, 04:47 PM
sorry it's a 1999 and it has the 3 knobs, not the auto feature. I pulled out the resistor block and it had some small debris on it. I'll try tracing back from the blower motor.

shorod
12-02-2006, 08:13 PM
Well, if you haven't already put the resistor block back in, you can start by checking for voltage to the block. You'll want to install the resistor block before testing for voltage at the blower motor.

-Rod

jrngmn
12-03-2006, 03:38 PM
Well, if you haven't already put the resistor block back in, you can start by checking for voltage to the block. You'll want to install the resistor block before testing for voltage at the blower motor.

-Rod

Well After taking the blower out and testing it on a bench it worked. No way to get a resistor block so I replaced the relay under the hood, it worked for about 1 hour sounded like it was getting slower and quit again. This sure sounds like the resistor block. Am I off base here, or should I order one from the dealer.

shorod
12-03-2006, 07:01 PM
If the blower motor has a faulty connection in it, it could run for awhile, but as it warms up, things start to expand and go open circuit. Next time it fails, I'd suggest you use a meter or test light on the motor and see if you still have voltage to the blower. If you do, I'd suspect the blower motor to be the issue. If not, then perform the same check at the resistor block, and on down the line until you find where there is no voltage.

-Rod

jrngmn
12-03-2006, 07:09 PM
If the blower motor has a faulty connection in it, it could run for awhile, but as it warms up, things start to expand and go open circuit. Next time it fails, I'd suggest you use a meter or test light on the motor and see if you still have voltage to the blower. If you do, I'd suspect the blower motor to be the issue. If not, then perform the same check at the resistor block, and on down the line until you find where there is no voltage.

-Rod

Thanks for your help I am electrically challenged. The relay was bad, would motor going open blow the relay?

truomega
12-03-2006, 08:20 PM
dont know if this helps any but my work truck is a chevy astro. For some reason, the blower motor kept cutting off on me and they i wacked it a few times and it came back on. Seems it was stuck so i sprayed some wd-40 and it solved that problem. Then later down the line, the motor for no reason at all would cyle on to full blast and no matter what i would do (lower the fan speed, change the vent position) the blower would keep at it on full blast. Even when i turned the car off and pulled th ekey out it still ran. Was very weird so the mechanic at the company swaped out the resistor block and problem was solved. Good luck to u.

MyTaurus8AChevy
12-03-2006, 08:33 PM
would motor going open blow the relay?
What do you mean by "motor going open"?

shorod
12-04-2006, 12:12 AM
If the motor has a thermal-related issue that causes it to go open after it's been running and heats up, it should not cause a relay to fail.

In what way was the relay bad? Was the coil open, or were the contacts stuck open or closed?

If the contacts were "welded," that would imply either a defective relay or a severe current draw at turn-on. If the blower fan is typically left on high speed when the car is started, those relay contacts are seeing a huge current surge when it closes. That can cause arcing, which leads to carbon tracing, reduced conductivity, and usually eventual "welding" of the contacts.

If the coil is open, then there may be a reverse emf diode that is faulty (not too likely) or the relay may have been faulty. An open coil would not be caused by a faulty blower motor. Rather, the coil probably failed due to poor assembly -- vibration failure due to a poorly prepared magnet wire, cold solder joint, or too long or too short coil wire lead to terminal.

-Rod

jrngmn
12-04-2006, 01:04 AM
I swapped out the relay on a whim because it was $7. When I pulled it out the contacts were discolored and looked electrically shorted (burnt). When the fan worked after installing the new relay, I figured problem solved. Then it stopped again and I'm assuming the same thing is going on. I won't have time to mess with it until Tuesday, but I will try the suggestions. thanks.

shorod
12-04-2006, 11:05 PM
You should attempt to determine the cause of the discoloration on the old relay contacts. Are you referring to the contacts external to the relay, or did you open the relay and physically inspect the "guts?"

If you are referring to the external contacts, you need to determine the cause of the discoloration. If the discoloration is actually due to arcing, you probably have a loose connection that should be remedied before it melts the relay connector or starts a fire.

If the relay had silver plated contacts, the discoloration may be due to oxidation, which is actually a better conductor than silver itself (silver oxide is actually one of the best conductors available).

-Rod

jrngmn
12-05-2006, 12:19 AM
You should attempt to determine the cause of the discoloration on the old relay contacts. Are you referring to the contacts external to the relay, or did you open the relay and physically inspect the "guts?"

If you are referring to the external contacts, you need to determine the cause of the discoloration. If the discoloration is actually due to arcing, you probably have a loose connection that should be remedied before it melts the relay connector or starts a fire.

If the relay had silver plated contacts, the discoloration may be due to oxidation, which is actually a better conductor than silver itself (silver oxide is actually one of the best conductors available).

-Rod


I'll exercise due diligence in the discoloration as it was the outside contacts. I think you were on the right path with the blower motor because it was working again today when I did a spot check after work. I'm thinking like you said it's going open after warming up. The resistor block seems to be working because I can change blower speeds without incident. Is the Autozone $40 blower good enough or do I spend the $108 at the dealer?

shorod
12-05-2006, 01:44 PM
The Autozone blower is probably good enough, but be aware that it may be a more "universal" style and MAY require you to solder wires and/or re-engineer the vent (if equipped).

If you opt to replace the blower motor, you may want to remove the old and make sure you can get the squirrel cage fan off without it breaking before going on your parts run.

-Rod

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