BobBorakovitz

my blower hasn't worked on high speed since I bought the car. Weird thing is that 10 years ago I had an '85 Firebird that had the same issue.

Anyway, I've replaced the high-speed blower relay and the switch itself and still have the same issue. I'm just wondering if anyone else has had this issue and what was the problem?

I'm just trying to save myself a little time here, I have to do a fuel pump & filter change this weekend & recharge my A/C, so I just don't think I'll have time to troubleshoot it myself. Maybe just a step in the right direction?

Thanks!

82CrossFire Z28

iTrader: (1)

I haven't had this problem, but have you checked for voltage at the high speed relay? Pull the plug off the high speed realy. The RED wire should be hot all the time. Connect a volt meter between the RED wire treminal and the BLACK wire terminal in the plug.

If you don't have 12 volts here then you have found your problem. The RED wire is connected to a fusible link (probably at the starter) and provides voltage and current to the blower motor for the HIGH SPEED switch postion only.

If you have 12 volts on the RED wire, place the ignition in run ( don't start the car) place the blower switch in HIGH and place the function slider in any postion except off. Now check for 12 volts between the ORNAGE and BLACK wire terminals in the plug. If you don't have 12 volts here, the ORANGE wire is broken some where between the blower switch and the realy. You will need to repair/replace it. The ORANGE wire provides 12 volts to the High Speed Realy coil when the HIGH position is selected on the Blower Speed Switch.

You might want to visit this link and check out Figure 45... the AC/Heat controls will be top center and top right in the diagram....

http://www.autozone.com/az/cds/en_us...rInfoPages.htm


Let us know what you find.....

Dave

JamesC

iTrader: (5)

Long ago, I experienced a similiar problem (though I don't recall if the problem occurred at high speed or the lower). In my case, the resistor was burned in two.

JamesC

82CrossFire Z28

iTrader: (1)

The resistors are in the low speed settings circuit. The high speed setting does not have any resistiors in the circuit.


So yes, if you are missing a low speed setting on the blower motor, you will also have to check the resistor package. It is located under the connector behind the high speed relay. Pull the connector, remove the two hex head screws and pull the resistor package out. If one or more of the wire coils is broken, you will have to replace the unit.

In the attached photo, the resistor network is under the gray connector. You may have to blow some of the dirt out of the way to see it clearly

Dave

sofakingdom

iTrader: (1)

The resistors are used in the low 3 speeds ONLY. They CANNOT POSSIBLY cause the high speed to fail.

Find the blower motor high speed relay. It will be a small box near the blower itself. You can follow the thick purple wire from the blower to the relay. The relay will have a couple of small wires, the thick purple one, and a thick red one. The red one feeds raw battery to the relay, which then feeds it to the motor, thereby bypassing the ENTIRE rest of the car's wiring and delivering the highest possible voltage to the blower. Or, maybe not.... follow the red wire away from the relay. It will go up, to the windshield cowl, and over toward the driver's side. About at the point where it reaches the pass side valve cover, you will find a connector. Disconnect that extremely stupidly designed connector and observe that it has burnt completely to ashes, like everybody else's. There's your problem, same as everbody else.

Cut that idiotic thing off; and replace it with a pair of the BIG THICK HEAVY-DUTY yellow slide terminals. Not, the little weenie ones that are just like the blue and red ones except with a yellow barrel; look for the BIG THICK HEAVY-DUTY ones. Try to find insulated ones if possible. If not, cover the outer one with a piece of heat shrink.

There is another similar connector that produces a similar result, except that this one disables the ENTIRE HVAC electric subsystem. To repair that stupidity, remove the HVAC control head from the dash; look at the "mode" switch, that's worked by the big lever; note that it has (I think) 3 wires: one green, one some other color that goes to the fan switch, and one brown. Follow that brown wire. It is the supply to the system from the car's main harness. About 15" or so into the dash from the control head, you will come upon a connector identical to that stupid one for the high speed blower feed, except this one will be smaller. It will be equally burnt to ashes. Replace it as well, with the same type terminals as described above.

After changing those 2 connectors out, you may be amazed at how much better your whole HVAC works; especially, the blower will blow more.

BobBorakovitz

just wanted to say thank you for your perfectly described fix, it worked like a charm! I now have all 4 speeds in my blower!


thanks to everyone else that helped as well!

I love this board!

kuulkatdadieo

iTrader: (1)

Sofa. Man if I could hug you I would. I followed this thread, and I was having the same exact problem. I cut the red wire's connector and put one of those heavy duty connectors on it. After I did that, it wouldn't start. I went back and moved a couple things and then it started. I don't what I did, but it did it. I havn't had the last couple speeds in two years, and now I have it for winter. Thanks THanks THAnks THANks THANKs THANKS

sofakingdom

iTrader: (1)

Glad it works!!

Do us a favor guys, and describe what that factory connector looked like when you unplugged it. Or, if you can, post a pic of it.

kuulkatdadieo

iTrader: (1)

Hey Sofa. Does this red wire have anything to do with the car starting?? I'm just making sure. Because, if it doesn't start at a later date, I'll know what it is. I drove around and it works great.

I couldn't figure out how to unplug it so I broke it in half.The plug is grey, and it was all burnt up inside. It almost looks like some kind of fuse inside. I'm getting a camera tommorrow, so I'll post a pic. then. Thanks again.

sofakingdom

iTrader: (1)

No, sure doesn't. I have no idea why working on that would have disturbed the starter.... the starter wires are down at the bell housing flange (or were when the car was built, anyway). Not even close together. Maybe it's just a coincidence.

Those connectors get SO BURNT UP sometimes, that you wonder how they could have worked long enough to get as bad as they are.

kuulkatdadieo

iTrader: (1)

Yea I think I might have touched the ignition coil wire or something. Because, when I turned the key it didn't do anything. I can't remember which wires I moved when I went back, but I moved a couple wires when it didn't start. IDK. I wonder why they have a connector there, why not just a solid wire? GM sure does do some weird things, sometimes.

sofakingdom

iTrader: (1)

Because the wiring is built in modules and installed according to the car's options.

The HVAC wiring harness is installed as part of the HVAC assembly; and plugs into the other harnesses of the car where necessary. That feed is one of those interface points.

Go visit a vehicle assembly plant sometime. It's a REALLY COOL eye-opening experience. Doesn't even matter too much what kind of cars, since they're all built pretty much similarly; just watching the PROCESS teaches you a great deal about how it's done. Lots of stuff you can apply to your own car work. I highly recommend the Corvette plant in Bowling Green, KY; about 22 miles or so north of the TN border, about 50 yards from I-65.

kuulkatdadieo

iTrader: (1)

That's kind of funny that you mention the Corvette Plant. I've been there twice in the past year. And I've been to the Museum twice too. I didn't even think about the need for the connector for the assembly process. It makes sense though, as they build it piece by piece and they want to get those cars out of the plant. So they put those connectors on there for the ease of installation. I'll get those pics. ASAP.

kuulkatdadieo

iTrader: (1)

This is the fix:



What it looks like-- Sorry for the quality on these ones

1986iroc350

iTrader: (1)

ok not sure what to do here. BUT my fan motor turns OFF and On so does my compressor for my a/c. will this resistor fix that problem? On Off On off. cant figure it out. im driving. ac is doing good then all of a sudden fan stops.. ac stops. roll the windows down.... as soonas i do that the ac starts again. drive with windows down for a few. ac comes on. then off again. what is the deal here?? checked alll connections. dont know what else to do. it even cuts off when just the vent is on. no blower no nothing. comes on intermitently.. please help me.. this florida HOT/rainy season is killin me.

gomez101380

I traced the red wire all the way to the other side of the car and i dont see a gray plug all i see is the big black one that is coverd in grime. Is that the one i need to target?

Rockguy

There is a pic of there for you. It looks black in that pic

gomez101380

There happens to be 3 pics there and two different color connectors. i know where the black one is how bout the gray one?

88 TA GTA

I did this and thought there was a break in the orange wire as I has 12 volts at red and none at the orange wire.

If I understand correctly, there are 3 types of heating systems:
- manual
- electronic
- automatic

If you have the electronic version as my GTA does there are two relays for the blower motor. One for main power to the switch and the larger 5 pin relay for the two highest settings . My fan switch didn't light up at all. I was going to replace the orange wire and noticed there wasn't any power at the switch, so I traced it back to the relay. (if you shake them and hear any noise, they most likely need to be replaced)
Be careful when getting a replacement relay. There are a few different types. Mine had 3 pins on the bottom and one on the top left hand side.
When I went to pickup the 1st replacement it had 3 on the bottom and one on the top right hand side, which naturally wouldn't work.

This is the correct one with a pic:

http://www.autozone.com/autozone/cat...&parentId=52-0

They also list this one but can't confirm (no pic avail.)

http://www.autozone.com/autozone/cat...&parentId=52-0

FYI: the connectors under the hood were there and didn't have heat damage

Thanks for everyones input, hope this helps!

New2Chevy

iTrader: (11)

I checked my plug by the passenger side on the thick red wire, and I unplugged it, and it did not appear to be burnt up. I'm having the same problem with my blower motor not working on "high." I'll cut the plug off and redo the wire with a yellow butt connector and see if that works.

New2Chevy

iTrader: (11)

OK, AT THE BOTTOM IS what the plug looks like guys. Even though mine did not appear burnt up at all, I cut it out and twisted the wires together and used a wire nut to connect the red wire back together. It still did not fix the problem. I grabbed my voltmeter and tested the following:

1) I unplugged the plug that goes into the relay.
2) Inside the plug, I checked the red wire (red and black) for 12 volts--it was good. I plugged the plug back into the relay.
3) I turned the ignition to the "ON" position and turned the blower motor switch to the highest setting--still no high speed blower motor.
4) I then unplugged the plug again and checked the orange wire (orange and black)--it was good. "Must be the relay." I thought. I was right.
5) I then went to Autozone and bought a new relay--PROBLEM FINALLY SOLVED!! YAY!!

The old relay "clicked" when I hooked a 9 volt battery to it, so IT IS TRUE THAT IF YOUR RELAY "CLICKS" WHEN A NINE VOLT BATTERY IS HOOKED TO IT, IT IS NOT NECESSARILY A GOOD RELAY!!

cdjump

I just wanted to say thanks for this. My 89 formula blower worked on all speeds, but was slow.
I changed out the high speed connector, and low and behold i now have a blower that actually blows a decent amount of air. I also stripped a little bit of wire off of the black ground wire at the blower, and soldered a short ground wire to it, which i then grounded to the body via self tapping screw, just to be sure i was getting an adequate ground.
Next time i'm under the dash, i'll replace the other connector as well, and lastly, i'm going to clean the connection of the red wire at the starter and clean it - might even replace it with a 10 gauge wire all the way to the connector i just replaced (i think its 12 gauge now), and that should help a bit more, but just replacing that connector and adding a ground made a huge difference.

Thanks again!!

edit - i should also note that last summer i replaced the blower motor, and cleaned the squirrel cage, and that made little to no difference.

cdjump

i just wanted to add one more bit to this. I decided to check my high speed relay just to be on the safe side. Pulled it off and one terminal was just about burnt to a crisp, so i went ahead and replaced the relay, and pulled the connector apart and cleaned the connector. That made my blower blow a bit harder still.

Slowridr

iTrader: (1)

Just cleaned mine and it did the trick. Hi speed blower is working now. This is what I cleaned. Yes it did look burned when I uncliped the gray connector with the large red wire on it. I just sraped some of the corroded looking material away and that was it.

Now Ive got another issue to work thru.

My HVAC will not switch between A/C, Max, Bi-Level, Vent, Deforst , Heat. Is it vaccum I know usually when yuo switch this you hear the sucking sound as the baffles move.

Last thing 3rd pic XH-7, does this mean this unit has been changed for R-134 refridge? Let me know what you think.

83T/A

Are these connectors on the older cars such as an 83 as well?I was looking on mine and didn't see it right off.I will dig deeper when i get home from work.

vertigo1202

iTrader: (1)

Hi what is the burnt black connector at the top of the first picture? I have the same thing and have a little trouble following. Thanks.
demorte1202@yahoo.com

dvernst

Connector on the hot wire for high speed was burned up pretty bad on mine. High speed worked occasionally, but I cut the connector off and soldered the wires together, and put heat shrink over it. Didn't see any reason why I would ever want to disconnect them again. Thanks for the advice ! Definitely Saved me time with trouble shooting! Thanks Dave

TheGr8erG00d

iTrader: (2)

I'm glad I found this thread. My connector was burnt out as well. This is one of four or five connectors I've found melted and ruined on my car so far.

UNCLE TOM

iTrader: (1)

yet another problem area i finally found today . i went through all of the above fixes yesterday & today . i'm a retired acft. mech. and am used to troubleshooting . i thought i had met the devil , i have invented several new 4 letter words , i have more scratches on my hands & arms than the national debt . seemed like the blower had a mind of it's own , worked now and again , off & on . no rhyme or reason , anyway the reason was connector on the TOP of the heater/a/c control unit . seems the clip/lock was damaged not keeping the connector fully engaged/connected . it just floated/bounced around and made contact every once an a while . now i have good a/c wich is vital here in the summer . need to figure a way to keep connector secure (maybe ductape) . anyway it was my DEVIL that i finally beat , hope this helps just one person . good luck , cheers !!!

rdsiler

I would like to say thanks too. The connector was bad on my car also. High speed fan is all good now.

leo27030

Hi i did everything above and even replaced my bower and all speeds work except the highest one when you get to the 3rd speed it works fine then when it's changed to the highest it turns off . was wondering what else I can check . Thanks forgot to say mines a 91 rs

88 TA GTA

There is a separate relay for the highest position its big and rectangular (unlike square relays) located at the back pass side near firewall under hood. Did you replace that?

leo27030

the only thing I see like that ,is to the right of the blower motor standing in front of it. It has a red wire and 2 purple wires and another wire commimg out of the bottom of it and has a number on top of it 4244 ,Looks like the bracket it's on was made to hold 2 but there's just the one . Is that what you were talking about ?

JamesC

iTrader: (5)

Sounds like it. Check post #4 of the following link for a pic. The resistors have the gray connector. Below them and to the right is the high-speed relay.

https://www.thirdgen.org/forums/elec...aro-rs-no.html

JamesC

leo27030

Just changed it out awhile ago and that fixed it , thanks so much for your help

ramosj88

So what is that black rectangular thang that kuulkatdadieo posted with the faded wires going to it (top of pic). Mine looks identical. A little crispy looking.

New2Chevy

iTrader: (11)

That black thing is something else not related to the power for the high speed blower. The two red wires with the yellow wire nut in your pic are what power the high speed blower. I did away with the little black plug and used a twist nut like shown in the pic, and the high speed blower still did not work. I changed the relay and the high speed blower then worked properly. See post 21 of this thread.

RadsGTA

Great write up SofaKing... I just recently acquired a 89 GTA and the high speed on the fan selector was not working in my car either. Followed your steps to remedy that problem and it worked. I'm curious tho. My fan now works on high but doesn't seem to push the air out of the vents very fast. Is there anything else that might be hendering it too? Or is this the max these units are capable of. Any other input would be greatly appreciated.

JamesC

iTrader: (5)

A new blower motor will likely impress you--did me anyway.

JamesC

acer1864

ughh, Im not getting power to my orange wire, therefore no relay ..also, the black ground wire attached to the blower motor has resistance when checked with a meter..?

rwstegne

Thanks!!! I just had te same issue. The blower motor worked on the first three speeds but not on the high speed setting. I had notice that connectore by the distributor was burn out but would have nver guessed it when to the highspeed side of the blower fan. Just cut the connector out, tight the two together quickly, tested it and problem solved. Sweet!!! Another defect off my list.

Does anyone know why that connector fails?
Does anyone recommend a replacement style connector?

Thanks again guys!!!

kmcn47

okay, not sure about anything to do with the blower motor relay resistor or anything, but mine shutoff the other day, and its only ever had three speeds? what is high speed? and none of my speeds work, i have since replaced the resistor, and the motor, nothing

Rockguy

High speed is simply the highest speed it will go. Start with the simplest things. Check the fuse. Should be a HTR/AC fuse. Probably 25 amps. You say you replaced the motor. Is there power on the wire coming to it? I think it's probably purple. Make sure the black wire has a good clean ground.

kmcn47

i've looked at my fuse box and i simply dont see a fuse marked htr/ac my dad and co workers all told me to check the fuse, but i really dont think my car has one, and it worked fine until sometime yesterday, never blew very hard but i've heard these cars dont

Rockguy

You can start by checking for voltage on the hot wire at the motor itself. If you have 12 volts there, then your problem is either the ground or the motor itself. If not, then you have to start looking for why. Check every fuse you have. Those are really the best places to start and it's free.

kmcn47

thanks guys, be sure to get on it when it stops raining

Maverick H1L

iTrader: (8)

First, an easy test for the motor and ground is to unplug the relay as described above and jump the RED terminal to the PURPLE terminal, as the relay does when HI is turned on. Fan runs, the motor and ground are good. Fan doesn't run, run a jumper to ground on the engine or somewhere and one of the bolts on the motor and try jumping the relay connector again. Fan runs, you need to run a new ground wire. If not, the motor is suspect. If the motor has never worked on HI before and it does now, try replacing the relay...

Of course, this doesn't work when the connectors are melted as above. Funny, though, neither of my connectors on the 87 (where the harnesses are out of) were burned up and I'm sure the POs of the car used the A/C at some point (car WAS from Alabama, after all).

HTR/AC fuse is right above the circuit breakers (when the breakers are at the bottom right when looking at the panel).

kmcn47

cool i found it thanks to my haynes manual, funny some useful knowledge in it for once, and i tested the old motor that way, it was fried, and so i figured it was my problem. my resistor looked fine, a but rusty but fine, the relay idk and i dont know of a way to test relays or where the hell i'd get one, maybe napa. but lately as its getting cold the cars just taking a big **** on me the exhaust is ready to fall off wtf it was just put on, *******s apparently used clamps and didn't weld it, it wont idle and all the blower **** is happening and its getting colder which sucks without a heater but gets dangerous without a defroster

Maverick H1L

iTrader: (8)

Well, about the only way to test the relay would be to get it to "switch" using a 9V battery on the coil contacts while checking the resistance on the switch side... If it's open when switched, it would be bad... Other than that, swapping it out is the only other way.

Rockguy

Napa probably has one or, you find one online? You might get a car alarm shop to sell you one too.