Heat/AC does not come on.

[gusu]

When I go to turn on the heat nothing happens, no fan comes on and no heat comes out. However, one of my belts is loose again so I can hear it scream for a split second while my heat comes on.

I checked the fuse box for everything that said heater and they were all good. I also checked the fuse box under the hood for blown fuses and didn't find anything. The actual heater one I have no idea how to check.

Any ideas why it might not blow any air at all? Even when switched to AC?

I'm also not hearing the blower fan come on at all. I'm also not feeling any radiant heat when the heat is turned on, I'm not sure I should be able to even feel anything with out the fan on or not. I don't really know anything about the heating/cooling system.

 

[zcoh2gdsm]

is there any tension when you turn the knobs? check the cables behind the glove box and make sure they're attached properly.

 

[Chill Kill Kult]

blower motor. plain and simple.

 

[gusu]

is there any tension when you turn the knobs? check the cables behind the glove box and make sure they're attached properly.

I haven't really noticed a difference but ill check when i get off work.

It did this out of nowhere as well, it worked great. Sat for a night then I went to drive my gf to work and the brake light was stuck on even though the ebrake had released. It's working properly now though. That's why I checked the electrical first.

Any idea on if the two could be related?

 

[assassin3117]

++1 on the blower motor. You should get a power probe and shoot power to the blower motor it self. If it comes on that way then the most likely cause is your blower motor resistor. I will have to look at the wiring diagram and check but I believe all modes including high runs on the same resistor. But again like I said get a power probe and shoot power to the blower motor itself.

 

[gusu]

++1 on the blower motor. You should get a power probe and shoot power to the blower motor it self. If it comes on that way then the most likely cause is your blower motor resistor. I will have to look at the wiring diagram and check but I believe all modes including high runs on the same resistor. But again like I said get a power probe and shoot power to the blower motor itself.

Can you give me a link to show me which kind? I've never bought one and know very little about them. Thanks for your help by the way.



*edit* I found a post by Steve that said this "There is a resistor for the low speeds. If the blower works on high but not on one or more of the lower settings you would check/replace the resistor. "

 

[98_gsx_]

i bet that is your blower motor

 

[gusu]

Is there any way to test the blower motor with something simple like a couple of paperclips and a battery? I don't want to go buy something I don't need.

By the way my blower motor is not coming on AT ALL. Everything I have read says the resister should work on one setting. Of course there is a chance both resisters may have blown. But I don't think that is likely.

Can anyone tell me how to test the fuses in the engine bay? I have a test light and a multimeter I can use. I just think it's weird that the blower motor would just stop completely and totally out of nowhere. Everything I've seen online people complained about horrible noises before theirs died.

Mine worked great the day before and the next night I went to turn on the car it would not come on at all, the same day as my e-brake light got stuck on. By the way it did it again on my way home from work today. I can hear the brakes releasing so I do know they are not getting stuck.

 

[DSMBanditFZ6]

Mine does the exact same thing (ecept when I hit the fan it kicks on my radiator fan ) I would definetly check out your blower motor. Replace it maybe just to see. I have a spare so its free for me but that's where I would start.

 

[gusu]

Mine does the exact same thing (ecept when I hit the fan it kicks on my radiator fan ) I would definetly check out your blower motor. Replace it maybe just to see. I have a spare so its free for me but that's where I would start.

That is EXACTLY what mine is doing.

 

[theoutlaw82]

Disconnect the blower motor connector and just run to jumper wires to motor. One off the battery for power and one to a ground. If it kicks on then you know its working. They can just quit like you said. I've had it happen to me before. I've also had the bearings go bad in one and seize.

 

[gusu]

Disconnect the blower motor connector and just run to jumper wires to motor. One off the battery for power and one to a ground. If it kicks on then you know its working. They can just quit like you said. I've had it happen to me before. I've also had the bearings go bad in one and seize.

Sweet, thanks for the information. I am going to disconnect it and try that. If it's broken I am going to try to see if it's something stupid like dirty bearings or something like that.

 

[Alky_dsm]

You can also check to see if you have power coming out of the harness connector with your meter if you are not getting source voltage it could be a fuse or a short

 

[theoutlaw82]

If you pull it also check to make sure theres nothing in the vent system jamming it.

 

[Lou98GSX]

unplug the blower motor and use a test light to check for power and ground at the harness connector that plugs into the blower motor. connect the test light at the battery + to test for ground and - to check for power.you will need a jumper wire to reach to the connector. if you have both then its the blower motor.

 

[gusu]

I pulled the motor and plugged it directly into the battery with some gator clips. I can confirm it is working.

I went to test the harness on voltage by connecting a couple paper clips to the harness, one to the positive and one to the negative. Made sure they were tight and they were, connected my multimeters positive and end to the positive and the negative to the multimeters negative. I got no reading on amperage with the car on and the heat turned on. So I though maybe I did something wrong with how I was running the meter and noticed on a youtube video this guy connected the negative of the harness to the frame of his car with a gator clip then used the negative on the multimeter on another part of the frame. Neither worked.

I don't know if I just tested it wrong or if it's actually bad. After reading several posts about the resister going bad on other people's care it sounds like it is not very likely at all that every setting on the heat wouldn't work. I guess it has multiple steps or something.

Anyway, I checked every fuse I could find that said heater on it on the fuse box inside the car. The fuse box on the driver's side of the car under the hood however I have no idea how the hell you test those things.


*edit* I replaced all the fuses besides those two round ones that say AC on them that are under the hood. Every other other fuse that said heat or AC on it got replaced. Didn't work and I wasn't expecting it to.

 

[steve]

Made sure they were tight and they were, connected my multimeters positive and end to the positive and the negative to the multimeters negative. I got no reading on amperage with the car on and the heat turned on.

Anyway, I checked every fuse I could find that said heater on it on the fuse box inside the car. The fuse box on the driver's side of the car under the hood however I have no idea how the hell you test those things.

You want to be measuring the voltage not amperage when checking for power to something. The chassis is ground and connected to the negative terminal of the battery so you can measure the voltage relative to ground by connecting the red probe to the thing your checking for voltage and clean metal of the chassis and get a reading. Make sure if you meter have different voltage ranges to use one where the expected voltage is less than the range on the meter.

For check fuses us the resistance (ohms) ranges. Pay attention to what you meter displays when the two probes aren't touching (an open) and when they are (a short). Now pull the fuse and measure between the two terminals. A good fuse measures as a short and a blown one as an open.

 

[Lou98GSX]

there is a fuseable link in the fuse box in the engine bay that powers up the blower motor relay . the relay is behind the dash on the drivers side if there is no power to it then its most likely the fuse . the fuse has like a clear plastic cover and the only way to test it is with a volt meter set on ohms . you remove the fuse and put the meter terminals on the fuse and you should get a reading on the meter. could also try swapping the fuse with a good one after you figure which one it is to see if your heater works.

 

[gusu]

Where are the control switch and resistor located? Anyone have any pictures?

*edit* I found the resistor but now I have another question.... how the hell do you get to the thing? I took out the radio hoping that, that would give me a clear shot and it still wasn't accessible.

*Update* I found out to remove the resistor you remove the glove box by squeezing it together while it's open then removing the two screws. I still have yet to find out where the switch is located. I have a feeling it is by the HVAC controls though.

I removed the resistor (the hardest part being the effing plug that does not want to come off) and the resistor had corrosion EVERYWHERE.

Yeah it was nasty.

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[gusu]

Well, no surprise but it wasn't the resistor. I didn't think it was but the old one was obviously on it's way out at the very least.

Still no luck on finding the switch though.


By the way, are those round things (the ones in the compartment fuse box and by the blower motor) a fuse or a relay or something totally different? I'm starting to get a feeling that maybe those are the problem.

Shouldn't the radiator fan not come on at all if the switch was bad?

 

[boosteclipse]

Since the blower motor has been tested good then it should be simple to diagnose. The system is pretty simple. You have a 30a fuse power then goes to the relay, then through the 10a fuse. After the 10a the power goes to one of the connectors on the fuse box, the large blue wire then runs straight to the blower motor.

First check to see you have power going in and out of the 30a, if good test the relay, if good test 10a fuse. If all those are good make sure the connector is snapped in good. ( that was why mine wouldn't work.) If thaws all test good, but still no power on the blue wire at the blower motor, then the is a short along that wire. Test resistance at start and end of wire to be sure.

 

[Lou98GSX]

went to check the wiring diagram and depending on when the car was built you could have a fuse able link or the ignition switch supply's voltage to the blower relay then from the relay it sends voltage to the blower motor so one of the terminals at the blower motor harness when it is unplugged should have 12 volts . the ground comes from the resistor . you can check that by putting the test light on the + side of the battery and moving your blower motor speed knob and watching the test light go from dim to bright.

 

[gusu]

Read new post.

 

[gusu]

Fixed the problem. Apparently my blower motor was bad, not sure why as even though it was getting a good connection it would only power on direct connected.

As for reading now power from the harness... that was my mistake. I like and idiot was forgetting to turn the key to the on position and not just til the radio turns on. Simple crap is easy to over look.

I never did find out how to check those relays though... one day.... maybe...