73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: darmentle on November 04, 2013, 08:18:52 am
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So its not working at all. So far i have done
-Replaced Relay
-Replaced and tested blower motor
-Checked Fuse
-Made Sure had power going into the HAC Control
I have power going into the relay but none coming out on the other side to that red wire that plugs into the blower. I am stumped. Maybe i got a faulty relay??
73 Chevy Factory Ac
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You can check your relay with a multimeter.
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Do you measure power on the yellow wire at the blower resistor with the fan switch set to minimum?
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No i havent measured anything with a multimeter yet i will try this week.
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A test light will work just as well.
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Still cant get the dang thing to work.
-Replaced blower relay
-Replaced blower
-Replaced blower resistor
-Cleaned wires and connections added a extra ground
-Getting 12 Volts to the resistor and 12 volts on both sides of the relay. just cant get power going to the red wire that goes to the blower motor.
Thoughts?
Worse case can i run the blower motor on a toggle switch ?
(http://i255.photobucket.com/albums/hh126/neothar/20131202_145438_zpse39da8b6.jpg)
(http://i255.photobucket.com/albums/hh126/neothar/hb2_zps28cb6c88.jpg)
(http://i255.photobucket.com/albums/hh126/neothar/20131202_145456_zpsea128b30.jpg)
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What are we working on here? Some details?
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Sorry 73 chevy factory ac
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There are a lot of posts on here for this already. Did you search? When the switch is on high you should have B+ at the blower relay at the orange wire. Do you?
http://forum.73-87chevytrucks.com/smforum/index.php?topic=22600.0
http://forum.73-87chevytrucks.com/smforum/index.php?topic=7117.0
http://forum.73-87chevytrucks.com/smforum/index.php?topic=12793.0
http://forum.73-87chevytrucks.com/smforum/index.php?topic=8201.0
http://forum.73-87chevytrucks.com/smforum/index.php?topic=16395.0
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Both orange wires with key on on high speed fan
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yes i have B+
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So what i noticed is there is a fuse that is suppose to be inline coming off the junction block . I will check on that later today.
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I was just going to ask where your 30AMP inline glass fuse is?
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I was just going to ask where your 30AMP inline glass fuse is?
i don't see one the one wire coming off the junction box goes all the way to the battery. Also if i had that fusible link where does it plug into at? the blower relay ?
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It's right above your thumb in the picture you posted
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It goes from the junction block on the firewall. The other end goes to the fat orange wire at the relay.
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so i just need to add in a fuse and wire to that wire above my thumb and hook it up to the junction box
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Trace the thick orange wire at the relay back til you find the end. Once you find the end take a pic.
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ok will do tomorrow
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I found the orange wire and the other end of the inline fuse cap. so i went to Napa and got a new inline fuse 30amp installed it still nothing at any setting this is making me crazy.
(http://i255.photobucket.com/albums/hh126/neothar/20131203_155713_zpse1087f13.jpg)
(http://i255.photobucket.com/albums/hh126/neothar/20131203_155705_zps02e05c61.jpg)
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OK now that you have it connected backprobe the orange wire at the relay to ensure it's live. Then with the key on and the blower switch on high check for B+ at the other orange wire at the relay. Report
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go by a test light tomorrow and let you know
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Do you have a meter?
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not here at my house would a test lite work i could go by one or a cheap multmeter?
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A test light will work for your purposes.
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ok im gonna grab one report back in a hour.
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popped the 30 in line fuse i put in . Can i just run it with out a fuse i have an extra relay just in case?
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No never bypass circuit protection ever!- Why don't you unplug the blower motor and unplug the resistor. Replace the fuse. Does the fuse blow still?
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I was going to replace the fuse but the extra ones i bought are to long for the inline one. I swear this thing is going to make me go crazy
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Patience Danielson. Put the fuse in and hold it in place with electrical tape for now just to satisfy your testing purposes.
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ill be wax on wax off be right back
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ok so i got power going threw the fuse and i now have power at the purple wire going to the blower. but as soon as i turn on the key i loose power to that purple wire going to the blower . now if i unplug the purple wire to the blower and turn on the key i get power. So now looks like something to do with the blower motor ? that was the first thing i replaced. what do you think?
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So what you are saying is with everything connected except for the blower motor you have B+ at the blower motor? Please clarify what's connected and what is not.
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OK so everything is connected but the blower motor wire i turn the key on i have power at the blower motor wire the purple one. So then i go to re attach the purple wire to the blower motor with everything connected now i turn the key on and now i am losing power to blower motor wire.
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OK and you have B+ at the orange wire still at the relay? After you confirm this you will need to run through a series of pinpoint tests.
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10-4 i have power going to the big orange wire at the relay
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After you've verified perform the following:
Reconnect all of the electrical connectors. Unplug the Blower Motor relay, connect your test light alligator clip to B+ and probe any ground to verify the light. Now take your probe and touch the terminal cavity for the relay #150 which is the black wire and ground for the relay. Your test light should light – Y or N?
Next with the key on engine off and the selector on heat and the fan switch in the high position, take your test light alligator clip to ground and touch B+ to verify the light. Now probe the smaller orange wire next to the black wire you just checked. It should illuminate – Y or N?
With your test light still connected to ground touch the big Orange wire at the relay connector and you should see your test light light up – Y or N?
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Ok i will finish this tomorrow after work let you know thanks again
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Ok start with the number 1
1 Yes
2 No no power small Orange wire
3 YES
After you've verified perform the following:
Reconnect all of the electrical connectors. Unplug the Blower Motor relay, connect your test light alligator clip to B+ and probe any ground to verify the light. Now take your probe and touch the terminal cavity for the relay #150 which is the black wire and ground for the relay. Your test light should light – Y or N?
Next with the key on engine off and the selector on heat and the fan switch in the high position, take your test light alligator clip to ground and touch B+ to verify the light. Now probe the smaller orange wire next to the black wire you just checked. It should illuminate – Y or N?
With your test light still connected to ground touch the big Orange wire at the relay connector and you should see your test light light up – Y or N?
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OK so now go to your fuse panel under the dash and with the key on check the fuse for the heater by probing both sides with your test light connected to ground. I believe it's a 25 Amp fuse that's supposed to be in there. Report
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The fuse is good have power going to both sides of it.
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OK so next step to get to the switch in the dash
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yeah i can pull that out check the connection. let you know make sure that the small orange wire is not cut
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Hang on, I just looked at your picture and see a dk green wire cut and a dk green wire with double white stripe coming out of the relay harness correct? If so join those two wire together.
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the one coming over by the relay is the one for the thermostaic switch i disconnected are you talking about the one next to the fire wall?
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Connect these two wires. Why did you disconnect it?
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ok let me connect them together ? don't have the thermostatic switch hooked up ac has been deleted.
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You're trying to be your own worst enemy aren't you? :P lol
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You're trying to be your own worst enemy aren't you? :P lol
i hooked the two green wires to each other nothing . Does the heater need the thermostatic switch hooked up in order to work. Also with my test light hooked up to B+ i touched the positive connection on the blower and did not here it spin up, so i checked the grounds i have and they are good. maybe a faulty blower ?
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Leave them connected and yes they need to be hooked up but for now just leave them connected. Your test light will not power up your blower motor, You would need to make a direct connection to test the motor but the problem you are having is no B+ at the purple wire and the little orange wire according to your test so stay on task. You need to check at the switch as mentioned above
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i have power at the purple wire now. is there suppose to be power at the small orange wire at the relay?
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OK so is the fan working now?
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no when i hook up the purple wire to the blower box i lose bower to the purple wire. its driving me crazy
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With your fan switch on high koeo in the vent position you have B+ at the little Orange wire at the relay Y or N?
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no
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OK, If you reconnect everything with the key on, blower on high and run a jumper wire to the small orange wire at the relay and touch the Battery positive post does anything happen? (use a jumper wire not your test light)
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i will check tomorrow when i get off . if haven't pulled my hair out by then. lol
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ok now it has a mind of its own .
At the relay
Key off
Big Orange wire Hot
Small orange wire no power
Purple wire no power
With the key on
Big orange wire has power
Small Orange wire has power
Purple wire has power
So i go to do your test with everything hooked up turn the key to on and pop goes the in line fuse. so now when the purple wire is hooked up to the blower its blowing that inline fuse.
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OK so take a jumper wire (fused preferably) and energize the blower motor directly from the battery. Does the blower motor run?
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nothing looks like that one is faulty. shot out some sparks haha im awake now
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Are you sure you have the correct squirrel cage on the blower and it's not binding?
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Look on the bright side, you've got most of it fixed/figured out as you've had a multitude of problems.
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yeah thanks for the help i will pick up a blower this weekend and update you
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I got it working but now the squirll cage is rubbing in side the blower box. If i back the screws off it doesn't rub is there suppose to be some kind of spacer that goes between the two?
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There shouldn't be any spacer. Do you have the correct squirrel cage on there? Is it new or old?
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it is old i just broke it so now i have to get a new one its like its to long for the box.
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Where did you get the blower motor from? If you get an aftermarket fan make sure you get a standard rotation and just check the length since they are typically universal.
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i got the new one from oreillys its the same as the old one.
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Although it may look the same as the old one it probably has the cage sit up higher.
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here a pic maybe that will help. i stopped at the parts store and they don't carry them in stock.
(http://i255.photobucket.com/albums/hh126/neothar/20131207_132702_zps59361843.jpg)
(http://i255.photobucket.com/albums/hh126/neothar/20131207_132713_zpscee98e29.jpg)
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Where are you located?
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Redding ca i know the pick n pull doesn't have my truck out there. Is it possible maybe a older Chevy car cage would work like a camero or a elcamino or a chevy van?
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Go to Napa http://www.napaonline.com/Catalog/Result.aspx?Ntt%3dblower%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3dblower%26Dk%3d1%26Dp%3d3%26N%3d0
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found a donor truck here my town the guy is gonna come let me pull the heater parts off for 20$
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Sweet i got it working finally !!!! So the will i got was the right one , the one that was in there was way to big. i need to take a look and check see if the ducting under the dash was removed. but drove it around just now and with in 8 min it got nice and toasty in side . thanks again vile.
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Glad you got it going, I just replaced mine in my 84C30 today. It was sounding real bad at times almost like the fan was hitting the firewall, there was a lot of up and down play in the motor. Sure glad I had a spare in the shed...
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Glad it's up and running. Make sure you go back and tidy up loose ends. If you are going to continue to bypass the thermostatic switch make sure you solder up those connections. Put the right fuses in the fuse holder etc. Cheers to having heat.