JeffP1167
Well-known member
I'm tired of spending money on getting my C68 system in my 90 working and was wondering how hard it would be to eliminate it and go with the mechanical setup
Any of you guys converted electronic climate control to mechanical?
- Thread starter JeffP1167
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mrvette
Phantom of the Opera
I would have to go look at my '87 book again, but it's really fairly easy to do, just make another control panel, as most GM's of the era had those electric operated vacuum control solenoids, that controlled the dash pots on the flappers....what I did in my '72 was junkyard source a bunch of those solenoids, and wire them to custom switches in my console, in place of the old HVAC controls...so I have complete electrical control over heater water, air flow, HVAC controls, two speed fan, and a electric motor from a later car runs the temp flapper back and forth with the pot on the position sender, taken apart and cut out with a dremel, the wiper on each end then lights a LED saying either full hot or full cool on the console, telling me the DPDT center off switch is at full hot or cool....manual position by holding the lever on the switch, it's not automatic....
that whole panel is one of my earlier projects from 15 years ago when I first got the car....:lol:
that whole panel is one of my earlier projects from 15 years ago when I first got the car....:lol:
JeffP1167
Well-known member
well I know 1990 had manual air so buying the control head cant be that hard but what I'm curious about is, what else needs to be changed.
mrvette
Phantom of the Opera
I bet it's still a lever with a flapper on a pivot....and the control motor is just a small motor with gearbox and a lever on it....mount the motor assy to the blower box, toggle the levers together, voltage one way, voltage the other like I did with my center off DPDT paddle sw...hold sw one side or the other...heat/cool...done...
Shillinger
Member
- Joined
- Mar 23, 2008
- Messages
- 19
I think a C4 electronic air door control is a small electric actuator that plugs onto the pivot for the door. No lever to attach your cable to.
mrvette
Phantom of the Opera
May well be, I used junkyard parts for the '72 project/mods....grabbed a extra while at it...
JeffP1167
Well-known member
the 90 has no levers off the motor, it is connected directly to the blend door shaft. Basically this motor sits right on top of the heater core box and the shaft for the blend door goes through the motor. So basically its a direct drive.
JeffP1167
Well-known member
Basically issues I have are this. After doing the heater core which was a pain in the you know what, then after reinstalling it and while running the a/c the a/c would stop blowing ice cold air and switch to heat. When it started doing this the indicator lights on my hvac control head would start to flash yet no codes would be displayed. Also while car at 200+ degress never got as hot of air out the vents as I would expect even when the climate control setting was at its highest temp.
Removed heater core once again! Found while system was working blend door would open like half way and just start fluttering like the gears in the motor were stripped out and this wouldn't allow the blend door to swing to the drivers side and full close for full heat. It would however close the blend door against the heater core for full cold.
Took motor apart and found no stripped gear no nothing. Nothing that would indicate why it would be doing this. Replaced this motor and this time tested it on the heater core box but not physically bolted into the dash.
Results now when coldest temp is selected motor turns blen door against the heater core for full cold. then when temp is raised by say 10 degrees the motor immediately swings the blend door to full closed on the other side (but does not do the fluttering half way any more or so it appears) I have only tested it so far with key on/engine off. However while doing this after a few minutes the indicator lights start flashing again.
So before putting this electrical ASS^&%* back together and it not working correctly and having to tear it apart again though I'de ask if in fact this operation sounds normal to you guys. Because the next step is yanking it all completely out of the car.
Will once the engine is running possibly change things since the temp sensors are working? Could these indicator lights be flashing because I have a temp sensor disconnected after I took the dash pad out? How exactly does the car detect inside temps? I know where the outside temp sensor is and the digital display seems to reflect accurate temps and does change temps from night to day.
Removed heater core once again! Found while system was working blend door would open like half way and just start fluttering like the gears in the motor were stripped out and this wouldn't allow the blend door to swing to the drivers side and full close for full heat. It would however close the blend door against the heater core for full cold.
Took motor apart and found no stripped gear no nothing. Nothing that would indicate why it would be doing this. Replaced this motor and this time tested it on the heater core box but not physically bolted into the dash.
Results now when coldest temp is selected motor turns blen door against the heater core for full cold. then when temp is raised by say 10 degrees the motor immediately swings the blend door to full closed on the other side (but does not do the fluttering half way any more or so it appears) I have only tested it so far with key on/engine off. However while doing this after a few minutes the indicator lights start flashing again.
So before putting this electrical ASS^&%* back together and it not working correctly and having to tear it apart again though I'de ask if in fact this operation sounds normal to you guys. Because the next step is yanking it all completely out of the car.
Will once the engine is running possibly change things since the temp sensors are working? Could these indicator lights be flashing because I have a temp sensor disconnected after I took the dash pad out? How exactly does the car detect inside temps? I know where the outside temp sensor is and the digital display seems to reflect accurate temps and does change temps from night to day.
mrvette
Phantom of the Opera
Does that motor run off some digital signal? or a straight 12v feed?? looks complex by that ~5 pin connector there....
:bonkers:
:bonkers:
JeffP1167
Well-known member
Inside the motor there are a bunch of gears. But one gear seems to do nothing its not a idler gear per say but seems more like a position sensor. I am wondering if that was the cause of the fluttering. I know there is also something called a climate controller in the car and being my digital temp display also displays codes and operating conditions of the system (which everything appears to be functioning) if this controller is why my indicator lights continue to flash but no fault codes are detected.
I spent quite a bit of money to get a functioning a/c system back in this car and time putting a new heater core into it. So I want this system to function correctly one way or another. When I bought this project car the a/c was all messed up and heater core bypassed.
Removing it all is a last resort since I used my buddies 90 vette for 4 weeks with the same system and loved it!
I spent quite a bit of money to get a functioning a/c system back in this car and time putting a new heater core into it. So I want this system to function correctly one way or another. When I bought this project car the a/c was all messed up and heater core bypassed.
Removing it all is a last resort since I used my buddies 90 vette for 4 weeks with the same system and loved it!
mrvette
Phantom of the Opera
I just figgered out what those extra terminals are for...the position pot...probably that idler gear turns that pot, like on my junkyard motor assy...looks for all the world like that is a ~1/4" shaft going into that unit....so that could be mounted with a lever to use something like my setup....
I could photo the extra unit, IF I can find it easy enough....the one on the car now is buries pretty good behind the map/trim and computer and other shit...
so that leaves two possibilities....5 connections...3 of them for the position sensor like the TPS on your throttle body...then and two for the drive motor....if there is another for ground there, you have to play with the ohm meter to figger out what/who is home there....I suspect they did the same thing, reverse the motor leads via the controller, to move that flapper one way or other....
I could photo the extra unit, IF I can find it easy enough....the one on the car now is buries pretty good behind the map/trim and computer and other shit...
so that leaves two possibilities....5 connections...3 of them for the position sensor like the TPS on your throttle body...then and two for the drive motor....if there is another for ground there, you have to play with the ohm meter to figger out what/who is home there....I suspect they did the same thing, reverse the motor leads via the controller, to move that flapper one way or other....
Shillinger
Member
- Joined
- Mar 23, 2008
- Messages
- 19
You were asking about the location of the in-car temperature sensor. The chart below has it listed as well as some other information that might be useful:
The C4 Corvette makes use of numerous sensors that feed information to the ECM/PCM (Electronic Control Module/Powertrain Control Module) and to the instruments on the dashboard. Even if the sensor is operated by vacuum or pressure, the output is converted into an electrical signal for processing by the ECM. Most faulty sensors will cause a trouble code to be set (resulting in a 'Check Engine/SYS ' Light) and also alter the performance of the automobile.
When troubleshooting the reason for the code, the normal approach is to go straight to the sensor and assume that it is faulty. While this may be the normal practice, you are strongly cautioned that it is seldom the sensor but rather a connector, a power problem or a grounding issue that is actually causing the problem. Or, the sensor may simply be doing it's job and reporting an occurrence that is at variance with what is allowed or expected by the ECM/PCM.
In any event, because the sensor really is the easiest thing to check, the following information is provided to assist you in determining if the device is operating properly. You will need a D-VOM (Digital Volt-Ohm Meter) to check the items below. It should have at least a 10 megohms per volt rating---something that will be shown in the specifications.
For those sensors listed below that have ohms listed as the measurement item, disconnect the negative battery terminal and then the sensor harness connector and measure the sensor's terminals.
For voltage measurements, you can obtain test harnesses from any of the Corvette specialty catalog houses.
Sensor Measured Value
Engine Coolant Temperature Sensor 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F
Engine Oil Temperature Sensor 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F
Oil Pressure Sender/Switch 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI
Fuel Quantity Sender 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full
MAT (Manifold Absolute Temperature Sensor) 185 Ohms @ 210 F, 3400 Ohms @ 70 F, 15,000 Ohms @ 40 F
Outside Temperature Sensor 4400 Ohms @ 60 F, 2200 Ohms @ 85 F
In Car Temp Temperature Sensor 4400 Ohms @ 60 F, 2200 Ohms @ 85 F
MAF (Mass Air Flow) Sensor .4 Volts @ idle, 5 Volts @ Full Throttle
Oxygen (O2) Sensor .1 Volt Lean Mixture, .9 Volt Rich Mixture
TPS (Throttle Position Sensor) .54 Volts Idle, ~ 5 Volts Full Throttle
Sensor Locations
Engine Coolant Temperature Sensor Front of engine, below Throttle Body
Engine Oil Temperature Sensor Left rear of engine, just above the oil filter
Oil Pressure Sender/Switch Top, left hand rear of engine
Fuel Quantity Sender Top of fuel tank, beneath filler pipe escutcheon panel
MAT (Manifold Absolute Temperature Sensor) Underside of manifold air plenum at rear
Outside Temperature Sensor Right side of engine, top right corner of radiator
In Car Temp Temperature Sensor Coupe: above left seat near interior courtesy light, Convertible: center of cargo compartment lid
MAF (Mass Air Flow) Sensor Front of engine ahead of throttle body
Oxygen (O2) Sensor Left side of engine, in exhaust pipe
TPS (Throttle Position Sensor) Right side of throttle body at the front
The C4 Corvette makes use of numerous sensors that feed information to the ECM/PCM (Electronic Control Module/Powertrain Control Module) and to the instruments on the dashboard. Even if the sensor is operated by vacuum or pressure, the output is converted into an electrical signal for processing by the ECM. Most faulty sensors will cause a trouble code to be set (resulting in a 'Check Engine/SYS ' Light) and also alter the performance of the automobile.
When troubleshooting the reason for the code, the normal approach is to go straight to the sensor and assume that it is faulty. While this may be the normal practice, you are strongly cautioned that it is seldom the sensor but rather a connector, a power problem or a grounding issue that is actually causing the problem. Or, the sensor may simply be doing it's job and reporting an occurrence that is at variance with what is allowed or expected by the ECM/PCM.
In any event, because the sensor really is the easiest thing to check, the following information is provided to assist you in determining if the device is operating properly. You will need a D-VOM (Digital Volt-Ohm Meter) to check the items below. It should have at least a 10 megohms per volt rating---something that will be shown in the specifications.
For those sensors listed below that have ohms listed as the measurement item, disconnect the negative battery terminal and then the sensor harness connector and measure the sensor's terminals.
For voltage measurements, you can obtain test harnesses from any of the Corvette specialty catalog houses.
Sensor Measured Value
Engine Coolant Temperature Sensor 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F
Engine Oil Temperature Sensor 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F
Oil Pressure Sender/Switch 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI
Fuel Quantity Sender 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full
MAT (Manifold Absolute Temperature Sensor) 185 Ohms @ 210 F, 3400 Ohms @ 70 F, 15,000 Ohms @ 40 F
Outside Temperature Sensor 4400 Ohms @ 60 F, 2200 Ohms @ 85 F
In Car Temp Temperature Sensor 4400 Ohms @ 60 F, 2200 Ohms @ 85 F
MAF (Mass Air Flow) Sensor .4 Volts @ idle, 5 Volts @ Full Throttle
Oxygen (O2) Sensor .1 Volt Lean Mixture, .9 Volt Rich Mixture
TPS (Throttle Position Sensor) .54 Volts Idle, ~ 5 Volts Full Throttle
Sensor Locations
Engine Coolant Temperature Sensor Front of engine, below Throttle Body
Engine Oil Temperature Sensor Left rear of engine, just above the oil filter
Oil Pressure Sender/Switch Top, left hand rear of engine
Fuel Quantity Sender Top of fuel tank, beneath filler pipe escutcheon panel
MAT (Manifold Absolute Temperature Sensor) Underside of manifold air plenum at rear
Outside Temperature Sensor Right side of engine, top right corner of radiator
In Car Temp Temperature Sensor Coupe: above left seat near interior courtesy light, Convertible: center of cargo compartment lid
MAF (Mass Air Flow) Sensor Front of engine ahead of throttle body
Oxygen (O2) Sensor Left side of engine, in exhaust pipe
TPS (Throttle Position Sensor) Right side of throttle body at the front
JeffP1167
Well-known member
Well, the new blend door motor seems to have fixed my problems of the blinking indicator lights. I ran the car for about an hour and it will BBQ you now. Before it would just kinda keep you warm. Its doing all the vent switching and automatic stuff and the compressor seems to kick on and off to give cooler air. So guess its all fine now.