C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Blower motor not coming on (87 coupe)

Thread Tools
 
Search this Thread
 
Old 05-01-2019, 07:34 PM
  #1  
killthesleeper
Heel & Toe
Thread Starter
 
killthesleeper's Avatar
 
Member Since: Jan 2019
Location: Stockholm, Sweden
Posts: 20
Likes: 0
Received 4 Likes on 4 Posts
Default Blower motor not coming on (87 coupe)

Hi,

I noticed that my vents weren't blowing any air.

At first I thought it was just gonna be dirt in the squirrel wheel, but when I removed the blower motor assembly it was still white, clean and spinning well.

Before reattaching the assembly I connected the connector that goes in the right of the motor, placed the assembly on top of the engine (so I could see it from the driver seat) and started the car.
No matter what AC/Heater setting, and fan speed, it didn't spin.
I unplugged the connector and tested a multimeter to the sockets, but could get any reading.
I have checked all fuses, and they're all whole.

Should I slice up the cables to the connector and check if I get a reading straight from the wires, or where should I start trouble shooting this?
Old 05-02-2019, 12:22 AM
  #2  
65Z01
Team Owner
 
65Z01's Avatar
 
Member Since: Dec 2000
Location: SE NY
Posts: 90,675
Likes: 0
Received 300 Likes on 274 Posts
Cruise-In II Veteran

Default

Does it have C68 or manual HVAC?

Anyway, you know there is no power to the fan motor so you need troubleshoot the controller.
Old 05-02-2019, 02:53 AM
  #3  
killthesleeper
Heel & Toe
Thread Starter
 
killthesleeper's Avatar
 
Member Since: Jan 2019
Location: Stockholm, Sweden
Posts: 20
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by 65Z01
Does it have C68 or manual HVAC?

Anyway, you know there is no power to the fan motor so you need troubleshoot the controller.
It has the manual HVAC.

The cold/hot slider seems to be working as I can feel a temperature change near the vents, and I can hear clicking from the engine bay when sliding through the different modes.
Old 05-02-2019, 06:31 AM
  #4  
Joe C
Race Director
 
Joe C's Avatar
 
Member Since: Aug 2000
Posts: 11,346
Received 700 Likes on 589 Posts

Default

hard to determine EXACTLY what the problem is without proper diagnostics. do you have a FSM? had a similar problem in my 85 awhile back - turned out to be the HVAC select switch. check out this thread - https://www.corvetteforum.com/forums...er-speeds.html --
Old 05-03-2019, 05:38 AM
  #5  
killthesleeper
Heel & Toe
Thread Starter
 
killthesleeper's Avatar
 
Member Since: Jan 2019
Location: Stockholm, Sweden
Posts: 20
Likes: 0
Received 4 Likes on 4 Posts
Default

Originally Posted by Joe C
hard to determine EXACTLY what the problem is without proper diagnostics. do you have a FSM? had a similar problem in my 85 awhile back - turned out to be the HVAC select switch. check out this thread - https://www.corvetteforum.com/forums...er-speeds.html --
I haven't yet gotten the FSM, but it's on my grocery list.

Thank you for your tip, I'll have a look at it.

For a while I thought it might be the resistor. But after taking it out last night I can't say that I see anything burnt on the coils or pints (the black stuff is just dirt).
I guess the search continues.

Old 05-03-2019, 07:12 AM
  #6  
hcbph
Safety Car
 
hcbph's Avatar
 
Member Since: Aug 2013
Location: Minneapolis Mn
Posts: 4,199
Received 526 Likes on 476 Posts

Default

The resistor cannot be checked by a visual inspection, at least in my opinion. Just changed one in my truck last fall that only worked on high, though looked fine it wasn't. You can try ohming it but for what they cost it's better to replace to test. The fact you have no speeds implies it's not the resistor. I'd check the fuse and wiring if you have no power at all to the fan.
Old 05-16-2019, 03:07 AM
  #7  
killthesleeper
Heel & Toe
Thread Starter
 
killthesleeper's Avatar
 
Member Since: Jan 2019
Location: Stockholm, Sweden
Posts: 20
Likes: 0
Received 4 Likes on 4 Posts
Default

I managed to trace the problem to the relay near the blower motor. I could hear the old one click when turning the AC on, but I guess it just didn't operate the way it should.
With the new relay my blower motor comes on in Lo, lo-mid and hi-mid.
However, when I put it in "Hi" the fuse blows.
I even tried putting in a 40A fuse for laughs, instead of the stock 25A, and it blew.

I found that the yellow wire going to the relay was skinned and showing lots of copper, so I wrapped that up in electrical tape. I can't see where else it shorts. But I guess that's a trouble shoot for another day.

Thank you all for your help.

Get notified of new replies

To Blower motor not coming on (87 coupe)




Quick Reply: Blower motor not coming on (87 coupe)



All times are GMT -4. The time now is 04:03 AM.