fan blower problem
Thread Starter
Instructor
Joined: Aug 2006
Posts: 151
Likes: 0
fan blower problem
Ok, I just finished my first project on my 72. took the radio out, got it working and changed some bulbs behind the gauges and in the console. I now this wasnt the most complex fix, but for a new guy, it was quite rewarding to get everything working. Now I need a little help with my ac/heater blower. When I purchased he car it was working, but just quit on me. I read in a previous post about an external fuse, 30 amp, located under the hood. I found one that was on the drivers side fender, hooked with other wires on what I guessed to be the horn relay. The fuse is good on it. Also found a plug at the end of the console under the radio, 3 wires connected to it, that is not plugged into anything. Was I looking at the wrong fuse? Could someone also tell me where the blower is located? Oh yea, the blower wasnt blowing very hard, even on high. Thanks for everyones help.
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
The fuse you found by the horn relay is the fan motor high speed supply.
If it is good, the next logical place to check is the relay mounted on the evaporator case under the hood and the ground and supply wire on the blower motor itself. The evap case holds the fan motor--it is located on the passenger side firewall.
Of course, make sure you didn't pull anthing loose from the fan switch on the center console when you did your bulb repair.
If it is good, the next logical place to check is the relay mounted on the evaporator case under the hood and the ground and supply wire on the blower motor itself. The evap case holds the fan motor--it is located on the passenger side firewall.
Of course, make sure you didn't pull anthing loose from the fan switch on the center console when you did your bulb repair.
Melting Slicks
Joined: Aug 1999
Posts: 3,123
Likes: 13
From: Hollywood, Florida
most of the "store bought" repair manuals are fairly generic. I'll look in my assembly manual and wiring diagram tomorrow and if something looks helpful....I'll scan and e mail you a copy
Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
If you want a good wiring manual I would suggest the
NCRS 1973- 1982 Corvette electrical wiring diagrams. It was purchased at Riks LIT 461 It has all you need to know. 73 Is as close to 72 not much change if any
NCRS 1973- 1982 Corvette electrical wiring diagrams. It was purchased at Riks LIT 461 It has all you need to know. 73 Is as close to 72 not much change if any
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Melting Slicks
Joined: Sep 2000
Posts: 2,403
Likes: 416
From: Chester Virginia
The Chevrolet Service Manual has a simplied schematic of the blower controls than the wiring diagrams, or at least in the 73 manual. Get the Chev Service Manual for a reference book.
Unplug the wire at the blower motor and check for voltage at the plug with the car running. Try all the different switch positions. If only high speed does not work then the relay probably will be the problem. If no speeds work then they will be an issue at the switch.
Roger
Unplug the wire at the blower motor and check for voltage at the plug with the car running. Try all the different switch positions. If only high speed does not work then the relay probably will be the problem. If no speeds work then they will be an issue at the switch.
Roger
Pro
Joined: May 2002
Posts: 518
Likes: 17
There's a resistor pack on the AC Evap Case as well, so when you run through blower speeds excepting high the juice will pass through this resistor pack (for high speed the resistor pack is bypassed, though the inline fuse is in use). These resistors can fail as well rendering one or more fan speeds other than high kaputt, even if the console switch is good.
Doug
Doug
Originally Posted by RMS73
The Chevrolet Service Manual has a simplied schematic of the blower controls than the wiring diagrams, or at least in the 73 manual. Get the Chev Service Manual for a reference book.
Unplug the wire at the blower motor and check for voltage at the plug with the car running. Try all the different switch positions. If only high speed does not work then the relay probably will be the problem. If no speeds work then they will be an issue at the switch.
Roger
Unplug the wire at the blower motor and check for voltage at the plug with the car running. Try all the different switch positions. If only high speed does not work then the relay probably will be the problem. If no speeds work then they will be an issue at the switch.
Roger
Thread Starter
Instructor
Joined: Aug 2006
Posts: 151
Likes: 0
OK, thanks again for everyones help. i've located the blower, I think, and it looks at though it has two wires running into a wire female plug that goes on the male end at the top of the blower. One of the wires plugs into the other using a black plug about 3/4 to an inch long. the wire that goes in there was hanging on by a few strands, and now broke off all the way by me handling it. Now my question is where under the hood can I find a negative ground to use with my volt meter? Also, the wire that broke, does it actually plug in the way I described or is this a permanant connection that it broke from? Once again thanks for all the help and patients.
