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AC Problems, 1987 Coupe

K

Key West Jack

Guest
My guess is that that one is under the dash. I would look to see if you have the one previously discussed and then go from there if need. Problem is this stuff can get kind of expensive. Mine (a 90) has the climate control with the module on top of the blower/evaporator compartment under the hood.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Ok Jack,

Fortunately, so far these little things seem relatively cheap. I even found the biggie (Evap core for $200 or less) but sounds like it is more in the line of either these modules or clog, blower, etc.

Appreciate your help on this.

Eric

My guess is that that one is under the dash. I would look to see if you have the one previously discussed and then go from there if need. Problem is this stuff can get kind of expensive. Mine (a 90) has the climate control with the module on top of the blower/evaporator compartment under the hood.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Jack,

Ok. I've done a couple checks. First, the last module that was presumed under the dash was actually the only one I could find and it is just above the blower under the hood.

First, I unplugged the main blower power and it already showed 12V. I unplugged the module, the blower turned off. There are about 6 pins so I had to guess a little but the opposing pins on the short ends closed the circuit and turned fan on and also registered 12V.

Not sure I accomplished anything there. I did connect one to another and got a little spark..oops. :)

The fan blows the same and by the way, between low and med, quite literally nothing but a little sound to let me know its on and really the only airflow is in high.

I felt the blower and not knowing how fast it CAN go, it is hard to tell if it as full speed but my gut feeling is that it could go faster. DO they just get old?

Doesnt look to easy to remove either.

So, not sure what to check now. The other module first mentioned seemed nowhere to be found. I did find another connector that had some resemblence just beside the blower but when I removed it, the blower continued so I am guessing that is not it.

ANy other ideas?

Thanks,
Eric

My guess is that that one is under the dash. I would look to see if you have the one previously discussed and then go from there if need. Problem is this stuff can get kind of expensive. Mine (a 90) has the climate control with the module on top of the blower/evaporator compartment under the hood.
 
K

Key West Jack

Guest
Eric, I think I am at a loss. Aparently there is a design change from your year to my 90. This is where we need the help of the FSM. I will ask around to see if someone has the wiring diagram. Will ask around over at corvette forum and some others. Some will help.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Jack,

Ok. Here are a couple of pictures of my actual setup. Maybe that will help.

Thanks,
Eric


Eric, I think I am at a loss. Aparently there is a design change from your year to my 90. This is where we need the help of the FSM. I will ask around to see if someone has the wiring diagram. Will ask around over at corvette forum and some others. Some will help.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Hey Jack,

Sent one back.

Appreciate the info. I ordered that hi fan module too since it was cheap. Thought it was worth a try.

Mostly I am just wondering if the fan can be receiving 12volts but maybe just plain old and not working to full capacity.

Eric


Eric, PM coming at you. Jack
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Hey jack,

I used some of the recent info and I confirmed a couple things that I knew, one the evaporator is good, the compressor is good and working (and I am aware of the slow leak but a separate problem), blowing cold air.

I think what i found that is most significant, well two things, one the fan does in fact only work in the high position. Before I thought I heard some fan movement in low and med but when I actually go to the blower it is not turning at all.

The second thing is the test on that blower relay, which coincidentally seems to be called "AC blower hi". Of the 5 pins, 3 are expected and DO show voltage. The other two are expected to show zero and less than 15ohms resistance. [A thought occured to me as I reviewed this post. The troubleshooting procedures are having me check the wires BEFORE they entire the relay. Not sure why I would get any resistance on the input to the relay, if anything the relay should provide the resistance, shouldn't it? That would indicate that a component prior to the relay would serve as the resistor. - Just a thought]

It says replace if they don't. Both showed zero. Now, since one pin no longer shows resistance, in my own little head, resistance means that probably controlled one of the lower speeds and not the higher. So I have no idea if replacing that will do anything more than give me back the low and med speeds but who knows.

However, since it is cheap, I had ordered it earlier today. Ecklers thinks that it might be my initial hunch, that the blower just needs to be replaced. But I have not been able to talk to anyone at length yet on the phone.

The only question nobody has answered was whether there has ever been a case in which the blower still works but does not blow as it did when it was new. In short, do they get old and slow down or is this an "either it works or doesn't" situation.

Anyway, appreciate the help from you and all.

Eric

Eric, PM coming at you. Jack
 
K

Key West Jack

Guest
Blowers are mechanical and like most mechanical things will wear out. Add to that dirt, age, heat in the engine compartment and I would believe they loose their punch over the years of normal use. It seems to me that one could probably check out the motor with a multimeter (I am not an electrical engineer):duh, as the amp draw may change as the motor wears out. Check out the FSM it more than likely has a trouble shooting guilde for the blower motor.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Removing AC Blower Motor for replacement

Hey Jack,

I'm pretty sure that the relay module is probably what is causing the blower to not work on low and medium but I am also replacing the fan just because it is old and might have a little more ummph to it.

The ecklers parts guy had told me it is only a couple bolts to remove but there are definitely more than that.

Do you happen to know how to remove this thing? From what I can see, the fan motor sticks out about 3 inches from the main casing for the fan. The motor appears to be connected to a "plate" with about 5 small bolts (like 1/4 or 3/8 inch). It doesn't look like there is even enough room to slide it out though so I am a little concerned.

And I hope that removing the entire casing is not the procedure since the blower casing seems to extend all the way around the evaporator core and everything. I can't imagine having to remove that.

Appreciate your help, or anyone else who might know.

Thanks,
Eric

PS: I included this image to show what i think I need to remove. The red arrows point to the small bolts I think need to come out, the thicker red arrow on the blower motor and the direction I believe it should come out.



Eric, PM coming at you. Jack
 
K

Key West Jack

Guest
Hey Jack,

I'm pretty sure that the relay module is probably what is causing the blower to not work on low and medium but I am also replacing the fan just because it is old and might have a little more ummph to it.

The ecklers parts guy had told me it is only a couple bolts to remove but there are definitely more than that.

Do you happen to know how to remove this thing? From what I can see, the fan motor sticks out about 3 inches from the main casing for the fan. The motor appears to be connected to a "plate" with about 5 small bolts (like 1/4 or 3/8 inch). It doesn't look like there is even enough room to slide it out though so I am a little concerned.

And I hope that removing the entire casing is not the procedure since the blower casing seems to extend all the way around the evaporator core and everything. I can't imagine having to remove that.

Appreciate your help, or anyone else who might know.

Thanks,
Eric

PS: I included this image to show what i think I need to remove. The red arrows point to the small bolts I think need to come out, the thicker red arrow on the blower motor and the direction I believe it should come out.




Yes, you are on it. It is a relatively easy thing to accomplish. Be sure to disconnect your negative battery cable, to help minimize temp. shorts and worse damage to the ECM. Good luck. Jack :beer
 
Joined
Jun 10, 2003
Messages
159
Location
Springfield, MO
Corvette
1996 LT1 automatic, Polo Green
Hey Jack,

I'm pretty sure that the relay module is probably what is causing the blower to not work on low and medium but I am also replacing the fan just because it is old and might have a little more ummph to it.

The ecklers parts guy had told me it is only a couple bolts to remove but there are definitely more than that.

Do you happen to know how to remove this thing? From what I can see, the fan motor sticks out about 3 inches from the main casing for the fan. The motor appears to be connected to a "plate" with about 5 small bolts (like 1/4 or 3/8 inch). It doesn't look like there is even enough room to slide it out though so I am a little concerned.

And I hope that removing the entire casing is not the procedure since the blower casing seems to extend all the way around the evaporator core and everything. I can't imagine having to remove that.

Appreciate your help, or anyone else who might know.

Thanks,
Eric

PS: I included this image to show what i think I need to remove. The red arrows point to the small bolts I think need to come out, the thicker red arrow on the blower motor and the direction I believe it should come out.

You're gonna have to remove the inner fender too.
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Crap. :)
Guess that is the answer to my comment about how it seems to not be enough room. So inner fender? Is that an easy task?
Appreciate your input.
Eric


You're gonna have to remove the inner fender too.
 
K

Key West Jack

Guest
Eric, it is not that difficult, just time consuming, but not bad at all.
 

vee93

Well-known member
Joined
Nov 15, 2002
Messages
585
Location
Mississippi
Corvette
1993 Medium Quasar Blue Metallic Coupe
Check the fan relay and the blower motor. Also check the harness wiring for a minor short-since you say you're getting a 'lil bit of cool air, just not the shiver me timbers amount it's suppose to be putting out. :w
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Sorry I missed this posting. Not sure how since I had this set up for notifications.

Anyway, fan relay, high blower relay, lo medium relay thing all replaced.

I replaced the blower motor with a new one and rode 10 miles, went into a store, came back out, started car up, blower dead.

I plugged in the old one and it worked. The new one offered maybe a marginal difference in output of air.

To the other poster, I changed to R134 but it is cold enough, just not enough output.

So, having said all this, one of the tech support guys at ecklers said it could be one of the "doors" that changes airflow from below to top, etc.

Does anyone have a procedure for checking the air ducts for clogs or pathways not routed properly?

Thanks,
Eric



Check the fan relay and the blower motor. Also check the harness wiring for a minor short-since you say you're getting a 'lil bit of cool air, just not the shiver me timbers amount it's suppose to be putting out. :w
 

kirkeric

Active member
Joined
Jul 17, 2007
Messages
42
Location
Maryland
Corvette
1987 Champagne Color Coupe
Jack,

It wasn't too bad really....just about 15 bolts or so. Of course I took it off twice since the brand new blower died shortly after installing. I sent it back for a replacement.

Eric

Eric, it is not that difficult, just time consuming, but not bad at all.
 

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