73 with A/C wiring question
05-24-2010, 07:58 AM
#1
Drifting
Thread Starter
73 with A/C wiring question
Ok, replaced a while back the wiring harness/Lectric Limited, after chasing some wires, correcting some ground issues and doing some meter work and looking at some wiring diagrams/some are different, I'm not clear on the blower tie in, and I removed the A/C unit a while back. I know orange/power and black/ground go to the blower, orange is not hot using a tester, somehow the purple wire was tied in, on my blower I have three tabs to connect to, the bottom double connector are tan and green that connect to the evap/blower, but with the ignition on one of the wires is hot. I can get the blower to run with purple/hot suppling the power, but then if orange goes to the capacitor then where does it plug into?, not back to the ground as they show????
Last edited by 73jst4fun; 05-24-2010 at 09:58 AM.
05-24-2010, 11:56 AM
#2
Drifting
Thread Starter
Think I found some answers comparing a 72 assembly manual to a 73, seems with A/C you cut the orange connector off/.125 stub from the break out on the harness and use the purple/hot to power the motor, at least that's what I'm assuming, cant find anything that definately says this, so now what happens at at the capacator if your not using orange...love this 73....
Last edited by 73jst4fun; 05-24-2010 at 12:04 PM.
05-24-2010, 12:07 PM
#3
Race Director
Not sure what your saying exactly. Do you have a capacitor at the blower motor,if so I would guess the purple plugs into the cap and the cap goes to the blower motor.
Or when you said capacitor did you mean resistors ?
Or when you said capacitor did you mean resistors ?
05-24-2010, 05:10 PM
#4
Drifting
Thread Starter
Last edited by 73jst4fun; 05-24-2010 at 05:12 PM.
05-24-2010, 05:28 PM
#5
Race Director
Hi Roger, it's definitely a capacitor, I verified that on a assembly manual, ...it works/purple wire going through the capacitor to the motor as well... this adventure all started to get the wipers working, I must have a bad ground or something with the wiper, if I hook up the wiper the left front turn signal doesn't work, either does the emergency flashers, and blows the fuse, but the right turn signal works fine, with the wiper disconnected the turn signals work fine, but flashers still dont work.....just fun....
Are you blowing the wiper fuse or turn fuse ?
05-24-2010, 07:33 PM
#6
Drifting
Thread Starter
Yes, I'm hooking up all the wires/3 wire connector, ground, and the blue and yellow wire, have hadthe wiper switch exposed so I could test it with a test light, then plug the switch back to the connector and try the wipers...ok, are there two fuses?, I'm not blowing the fuse under the dash.....
Last edited by 73jst4fun; 05-24-2010 at 07:35 PM.
05-24-2010, 07:57 PM
#7
Race Director
I'm getting mixed up now (must be time to eat 
). You said you were blowing a fuse. Maybe you mean the high speed blower fuse in the engine compartment ? We were talking about wipers,turn signals,blower and hazards they all have different fuses.
Dinner time...maybe I can focus after some Fazoli's.
). You said you were blowing a fuse. Maybe you mean the high speed blower fuse in the engine compartment ? We were talking about wipers,turn signals,blower and hazards they all have different fuses.Dinner time...maybe I can focus after some Fazoli's.
05-24-2010, 09:53 PM
#8
Drifting
Thread Starter
I'm getting mixed up now (must be time to eat ). You said you were blowing a fuse. Maybe you mean the high speed blower fuse in the engine compartment ? We were talking about wipers,turn signals,blower and hazards they all have different fuses.
Dinner time...maybe I can focus after some Fazoli's.
). You said you were blowing a fuse. Maybe you mean the high speed blower fuse in the engine compartment ? We were talking about wipers,turn signals,blower and hazards they all have different fuses.Dinner time...maybe I can focus after some Fazoli's.
05-24-2010, 10:47 PM
#9
Race Director
I'm sitting here going over a wiring diagram. I really don't think you have just 1 problem. You seem to be crossing circuits. The turn signals and hazards can be a problem in the turn signal switch. The hazard fuse blowing when the wipers are turned on is what is puzzling. Its not uncommon for the wiper motor to have lost its ground and then try back grounding through the blower motor AC wiring.
The wiper and blower ground is a black 14 that comes up from the starter wiring loom. The black 14 should go on 1 of the starter mounting bolts or 1 of the bellhousing bolts BUT on occasion because the eye on the wire is so large it gets put on the pos post of the starter solenoid,this makes the case of the wiper HOT and can do all kinds of funny things.
The wiper and blower ground is a black 14 that comes up from the starter wiring loom. The black 14 should go on 1 of the starter mounting bolts or 1 of the bellhousing bolts BUT on occasion because the eye on the wire is so large it gets put on the pos post of the starter solenoid,this makes the case of the wiper HOT and can do all kinds of funny things.
05-25-2010, 06:09 AM
#10
Drifting
Thread Starter
I'm sitting here going over a wiring diagram. I really don't think you have just 1 problem. You seem to be crossing circuits. The turn signals and hazards can be a problem in the turn signal switch. The hazard fuse blowing when the wipers are turned on is what is puzzling. Its not uncommon for the wiper motor to have lost its ground and then try back grounding through the blower motor AC wiring.
The wiper and blower ground is a black 14 that comes up from the starter wiring loom. The black 14 should go on 1 of the starter mounting bolts or 1 of the bellhousing bolts BUT on occasion because the eye on the wire is so large it gets put on the pos post of the starter solenoid,this makes the case of the wiper HOT and can do all kinds of funny things.
The wiper and blower ground is a black 14 that comes up from the starter wiring loom. The black 14 should go on 1 of the starter mounting bolts or 1 of the bellhousing bolts BUT on occasion because the eye on the wire is so large it gets put on the pos post of the starter solenoid,this makes the case of the wiper HOT and can do all kinds of funny things.
yes,
Roger, I found that problem before while tracing the wires Sunday, and with putting in a new engine recently, with such a big eye I and others assumed that it belonged on the solenoid. I removed it and have a good ground on the scattershield now.
Last edited by 73jst4fun; 05-25-2010 at 06:14 AM.
05-25-2010, 07:20 AM
#11
Race Director
I have seen varying damage from that mistake , no damage to frying an entire harness.
Not sure if your problem is fixed or not , if not since the engaging of the wiper motor is blowing the fuse I would try to run a temporary ground from the wiper motor to the neg term of the battery.
Make sure the 14 black at the scattersheild is in fact grounding through to the neg terminal of the battery, remember the ground cable that jumpers the passenger side motor mount is crucial for a solid chassis to engine ground. (The ground path is as follows ... neg term battery to neg battery cable to frame connection under battery through the frame to the jumper ground cable at the passenger motor mount through the cable over and around the rubber motor mount to the engine block to the 14 black you grounded at the scattersheild.)
05-25-2010, 07:34 AM
#12
Drifting
Thread Starter
Very common mistake with starter replacements and engine installs.
I have seen varying damage from that mistake , no damage to frying an entire harness.
Not sure if your problem is fixed or not , if not since the engaging of the wiper motor is blowing the fuse I would try to run a temporary ground from the wiper motor to the neg term of the battery.
Make sure the 14 black at the scattersheild is in fact grounding through to the neg terminal of the battery, remember the ground cable that jumpers the passenger side motor mount is crucial for a solid chassis to engine ground. (The ground path is as follows ... neg term battery to neg battery cable to frame connection under battery through the frame to the jumper ground cable at the passenger motor mount through the cable over and around the rubber motor mount to the engine block to the 14 black you grounded at the scattersheild.)
I have seen varying damage from that mistake , no damage to frying an entire harness.
Not sure if your problem is fixed or not , if not since the engaging of the wiper motor is blowing the fuse I would try to run a temporary ground from the wiper motor to the neg term of the battery.
Make sure the 14 black at the scattersheild is in fact grounding through to the neg terminal of the battery, remember the ground cable that jumpers the passenger side motor mount is crucial for a solid chassis to engine ground. (The ground path is as follows ... neg term battery to neg battery cable to frame connection under battery through the frame to the jumper ground cable at the passenger motor mount through the cable over and around the rubber motor mount to the engine block to the 14 black you grounded at the scattersheild.)
05-25-2010, 09:13 AM
#13
Race Director
Check the pics in this post. The soldered junction can be iffy sometimes. You may want to ring out all the grounds separately to test. If you get into the harness and resolder, I would increase the ground wire size and solder all crimps, especially the one for the blower.
http://forums.corvetteforum.com/1573717874-post13.html
Also check the ground at the alternator and the drivers side core support sheet metal screw for the lighting (hazards)
http://forums.corvetteforum.com/1573717874-post13.html
Also check the ground at the alternator and the drivers side core support sheet metal screw for the lighting (hazards)
05-25-2010, 10:12 AM
#14
Race Director
Check the pics in this post. The soldered junction can be iffy sometimes. You may want to ring out all the grounds separately to test. If you get into the harness and resolder, I would increase the ground wire size and solder all crimps, especially the one for the blower.
http://forums.corvetteforum.com/1573717874-post13.html
Also check the ground at the alternator and the drivers side core support sheet metal screw for the lighting (hazards)
http://forums.corvetteforum.com/1573717874-post13.html
Also check the ground at the alternator and the drivers side core support sheet metal screw for the lighting (hazards)
But I am suspect of the 14 ground that was hooked up to the battery positive possibly burning into adjacent wires creating cross circuits.I think you might be best to unhook the wiring going to the starter including the 14 ground and using an ohm meter to see if the 14 black is fused with another wire.
05-25-2010, 11:03 AM
#15
Drifting
Thread Starter
But I am suspect of the 14 ground that was hooked up to the battery positive possibly burning into adjacent wires creating cross circuits.I think you might be best to unhook the wiring going to the starter including the 14 ground and using an ohm meter to see if the 14 black is fused with another wire.
05-25-2010, 11:20 AM
#16
Race Director
But I am suspect of the 14 ground that was hooked up to the battery positive possibly burning into adjacent wires creating cross circuits.I think you might be best to unhook the wiring going to the starter including the 14 ground and using an ohm meter to see if the 14 black is fused with another wire.
Disconnect all the grounds, test for voltage with different items on, then test the ground wires individually for continuity.
If I were keeping the car, I would redo the engine harness anyway, with bigger grounds soldered.
05-25-2010, 02:44 PM
#17
Burning Brakes
Hello,
I don't know if it's still relevant, but I looked at the wiring & aim of my 74. In the aim there is a special page for AC optioned cars, where it says the orange wire + connector needs to be cut off. It's indeed the purple one going to the blower motor. The AC wiring harness ground plugs on the other pin on the blower motor casing, the other plug fits into the engine harness (& then going to the ground points as described by Roger)
If you want I'll scan the aim page and take some pictures tomorrow?
Regards,
Nick
I don't know if it's still relevant, but I looked at the wiring & aim of my 74. In the aim there is a special page for AC optioned cars, where it says the orange wire + connector needs to be cut off. It's indeed the purple one going to the blower motor. The AC wiring harness ground plugs on the other pin on the blower motor casing, the other plug fits into the engine harness (& then going to the ground points as described by Roger)
If you want I'll scan the aim page and take some pictures tomorrow?
Regards,
Nick
05-25-2010, 03:06 PM
#18
Drifting
Thread Starter
Hello,
I don't know if it's still relevant, but I looked at the wiring & aim of my 74. In the aim there is a special page for AC optioned cars, where it says the orange wire + connector needs to be cut off. It's indeed the purple one going to the blower motor. The AC wiring harness ground plugs on the other pin on the blower motor casing, the other plug fits into the engine harness (& then going to the ground points as described by Roger)
If you want I'll scan the aim page and take some pictures tomorrow?
Regards,
Nick
I don't know if it's still relevant, but I looked at the wiring & aim of my 74. In the aim there is a special page for AC optioned cars, where it says the orange wire + connector needs to be cut off. It's indeed the purple one going to the blower motor. The AC wiring harness ground plugs on the other pin on the blower motor casing, the other plug fits into the engine harness (& then going to the ground points as described by Roger)
If you want I'll scan the aim page and take some pictures tomorrow?
Regards,
Nick
Roger, Wilcox Corvettes has a page on testing the wiper motor for a 73, pulled the motor and it works fine at high and low speed so that's a relief...
Last edited by 73jst4fun; 05-25-2010 at 03:08 PM.
