Heater fan switch? Or Relay problem?

[57chevyragtop]

I'll give that a try j cAT, I keep a solution handy for air leaks (Tires & natural gas).

[57chevyragtop]

OK, got the panel off...had to go buy a few tools 1/4 swivel for one...I think I am going to take the fan motor down as well for easier access and full inspection. May be a water leak to consider foam on bottom of fan motor was damp. windshield (has been replaced) or body seam. I'll post what I find.

[j cAT]

Originally Posted by 57chevyragtop

OK, got the panel off...had to go buy a few tools 1/4 swivel for one...I think I am going to take the fan motor down as well for easier access and full inspection. May be a water leak to consider foam on bottom of fan motor was damp. windshield (has been replaced) or body seam. I'll post what I find.

this could be the issue water causing failure..... if this is the case fix leak before new motor.......

[57chevyragtop]

Originally Posted by j cAT

this could be the issue water causing failure..... if this is the case fix leak before new motor.......

Yeah I'll have to find that for sure..pretty cold here and no warm area for working it out, going to put this off for a while till warmer weather enables me to do leak testing. So far last 2 days it's been working on high pretty steady ( NO CUT OUT). Hope to get some warming trend next week and I know how hard it is find leaks you often see the results but not the cause..I'll need some time on this project.

[Kemi]

Originally Posted by j cAT

the original first post stated that the blower did not work at any speed I have troubleshot many of these and its usually the motor brushes worn or corroded connectors......... ...

Right, but the fan is sometimes working on high speeds. It will not work at all on any of the lower speeds. That usually means the resistor. At high speed, the resistor is not needed, which is why the fan will work. Sometimes, GM builds the relay into the resistor which would explain why it will intermittently not work on high. Of course, the motor could also be bad. I'll check my repair source.

[Kemi]

57chevy,

I checked your blower circuit, and the resistor includes the relay for the circuit.

Orange wire #1 = Power to relay
Orange wire #2 = High speed from switch
Black wire/s = Ground
Yellow = Low speed input
Tan = medium one input
Light blue = medium two input
Purple = medium three

Let me know if I can help any further.

[57chevyragtop]

Kemi, thanks for the look up....I knew that from the replacement resistor I purchased that the relay is built in. Actually it's a combo of three resistors in a circuit. I just have to wait for a warmer day to do the leak check, no sense replacing part till I discover the main cause of failure if it is a water leak. It definately was not antifreeze and don't think it could be condensation. I just can't deal with the cold like I used to or I would be out there working on it now. Yes I know you were responding to a post by j cAT in your previous post and I do appreciate all input. Thanks to all ya'll....!

[j cAT]

[quote=57chevyragtop] no sense replacing part till I discover the main cause of failure if it is a water leak. It definately was not antifreeze and don't think it could be condensation. I just can't deal with the cold like I used to or I would quote]

If this was not antifreeze then the most likely explaination is the condenser air box drain hole is plugged.... as water snow or condensate from a/c collect in box this drain removes moisture so clean out the drain hole and bottom of air box from debris......

[Kemi]

Originally Posted by 57chevyragtop

Kemi, thanks for the look up....I knew that from the replacement resistor I purchased that the relay is built in. Actually it's a combo of three resistors in a circuit. I just have to wait for a warmer day to do the leak check, no sense replacing part till I discover the main cause of failure if it is a water leak. It definately was not antifreeze and don't think it could be condensation. I just can't deal with the cold like I used to or I would be out there working on it now. Yes I know you were responding to a post by j cAT in your previous post and I do appreciate all input. Thanks to all ya'll....!

You're welcome. If you need help for further electrical diagnostic just ask. I do believe the resistor is bad. But like I said earlier, there may be more than one problem. And Jcat is right. Definitely check the motor. Could be a water leak and/or an intermittently failing motor. I've seen both before. Good luck and post more if you need more help. Plenty of good people here.

[Kemi]

57chevy,

One more thing. Don't necessarily rule the resistor out as the 'main cause'. For instance, don't think that another part would have to 'ruin' the resistor. They go bad on their own. In fact, it's somewhat of a chronic problem for GM. They have several recalls and TSB's about this. Several 'enhanced designs' and 'replacement styles' for this part. Good luck.

[brcidd]

Yeah , I go along with the plugged drain theory-- GM W-cars are the only GM vehicle to use a "nipple" on the end of the drain plug rubber elbow tube-- all othe vehicles use a regular elbow- wide open at both ends- but W-car uses a nipple on the end- to reduce air losses out that hole- but it plugs rather easily-- you can access this elbow from engine side of firewall- with your left hand- in center of firewall in the recessed area - standing on passenger side- looking forward- and feel for the elbow- pull it off and see if it is plugged- I had a W-car once put a gallon of water on the floor when I pulled off the elbow- I also have seen W-cars "process" that water like a blender when turning hard left- blows the water out the vents even--

If this is the case- trim the nipple off the end of the elbow tube- and be sure to put the elbow tube back on- if you don't then there is another scenario brewing- the water will not drain out at highway speeds- and after an hour of non-stop driving the water comes out onto the floorboard- due to air pressure not letting the water flow out the drain- the elbow creates the "chimney effect" to draw the water out at highway speeds......good idea to check yours- I trim every W-car I get in- just for future problem avoidance.....

[57chevyragtop]

Wow! I am totally amazed at the helpful responses and the thoroughness of details by all of you. Thanks so much, I will check that drain hose at the first opportunity to do so. I will be a bit busy the next few days with some other business, but be assured of my appreciation till I can return and post. dave

[j cAT]

Originally Posted by 57chevyragtop

Wow! I am totally amazed at the helpful responses and the thoroughness of details by all of you. Thanks so much, I will check that drain hose at the first opportunity to do so. I will be a bit busy the next few days with some other business, but be assured of my appreciation till I can return and post. dave

no problem thats what these forums are for help people, save money.... I f you have removed blower motor just hook it up to 12volts to see if it runs properly and while running give it a few hits to see it it cuts out,,,,,

[57chevyragtop]

Hey guys, It's been a hard 4 weeks weather and injury wise. I was able to attack the leak problem today and here is what I found: The rubber body gasket below windshield and cowl had come off or was not put on securely after windshielad replacement...the cabin filter was soaked as a result water was also getting to fan motor and resistor pack. Bought a new filter, cleaned and secured body gasket. Have not yet installed the resistor pack due to injury still healing (fell hard in the snow couple of weeks ago). Thought you would like an update on this. I will post when I am able to get to the other part of repair I am figuring two weeks more healing. Thanks again for all your input, it has been of help....little dave!

[57chevyragtop]

Fixed! managed to get to this work today. removed and renstalled same fan, while fan was out I replaced the resistor pack with a new one. Getting this out was the most difficult part, only one screw needs to be removed the 2 closest to the firewall just need a few turns as the pack has 2 slotted screw U-shaped openings on that side. used 1/4 drive w/universal+5/32 deepwell socket...a short 1/4 wabble extension would work with the deepwell too but I couldn't find one....All works well now, Thanks again all....dave