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If the wires are light blue and dark green it would be for the power steering cutout switch as shown in this diagram . It's function is to shut off the AC compressor clutch when the power steering pressure gets above a certain level . The idea being that at an idle , with the AC on , if the steering wheel is turned abruptly the increased load could cause a drop in engine rpm , so the compressor is shut off momentarily to mitigate that rpm drop .
Last edited by OrangeBird; 07-03-2019 at 10:48 AM.
If the wires are light blue and dark green it would be for the power steering cutout switch as shown in this diagram . It's function is to shut off the AC compressor clutch when the power steering pressure gets above a certain level . The idea being that at an idle , with the AC on , if the steering wheel is turned abruptly the increased load could cause a drop in engine rpm , so the compressor is shut off momentarily to mitigate that rpm drop .
Funny that they used the same connector as the A/C pressure switch on the dryer. Have to admit it's been awhile since I looked at an early car. On the later cars they used a more modern connector, either a weatherpack or metripack on my 91 V6. In general that switch seems to be limited to the lower output engines, aka V6s and carbed cars. Another piece of useless trivia to file away and forget about.
Oh sorry, I haven't been paying enough attention to this thread . Trying to do too many things at the same time. I was thinking we were referring to the connector I showed in post #2
but on second look it's smaller and doesn't have the two slots in it for the other valve. DOH!
We're on the same page now. When I saw this thread last night, I was thinking the same connector as you. With it being on the driver's side narrows it down to the switch I always forget about.
What it does is measure the psi in the PS pressure line, when the pressure goes up, increasing the load on the PS Pump, it turns off the AC compressor to take the load off the engine so it doesn't stall.
Also of interesting note , the switch is monitored by the ECM (on 8 cylinder cars) by the dark green and light green wires connected across the switch labeled "To Engine Control" on the diagram . For the ECM to need that little bit of info means that it's very likely altering the carb's mixture control solenoid position slightly in response to the increased load , as well as of course cutting off the AC .
We're on the same page now. When I saw this thread last night, I was thinking the same connector as you. With it being on the driver's side narrows it down to the switch I always forget about.
Ah, I completely missed that part. Always good to be reminded by self to pay attention...
Also of interesting note , the switch is monitored by the ECM (on 8 cylinder cars) by the dark green and light green wires connected across the switch labeled "To Engine Control" on the diagram . For the ECM to need that little bit of info means that it's very likely altering the carb's mixture control solenoid position slightly in response to the increased load , as well as of course cutting off the AC .
Well, since I've ditched the ECM, does that mean this circuit is no longer functioning anyway?...
Well, since I've ditched the ECM, does that mean this circuit is no longer functioning anyway?...
If you've ditched the ECM , and replaced the ECM controlled carb and distributor with non electronically controlled units , then your fine . If you just got rid of the ECM and left the original carb and distributor in place , the lack of ECM based timing control and mixture control would be a far worse detriment to running than the lack of the PS switch would ever be .
PS , I'm not sure about the later cars as Drew mentioned , but on the earlier carb cars (like your 1983) those dark green and light green wires go straight to the ECM to let it know that the power steering is loading the engine a bit more than normal .
Last edited by OrangeBird; 07-04-2019 at 07:21 AM.
Also , I was wondering after hearing you ditched the ECM , with no ECM how are you controlling the torque converter clutch solenoid to lock up the converter ?
Also , I was wondering after hearing you ditched the ECM , with no ECM how are you controlling the torque converter clutch solenoid to lock up the converter ?
I have a non-ECM Quadrajet and a vacuum advance HEI distributor.
I have a torque converter lock-up kit from Monster transmission but have not installed it yet.
So just to make sure I'm clear on this; is this connector useless now that there's no ECM? Should I just cut it off and tuck the wires into the harness?
PS , I'm not sure about the later cars as Drew mentioned , but on the earlier carb cars (like your 1983) those dark green and light green wires go straight to the ECM to let it know that the power steering is loading the engine a bit more than normal .
Well, shows what happens when I look at something briefly in passing and don't check my notes... I was looking at too many diagrams and got myself mixed up. On the 91 diagrams, both TBI and the 3.1, the PS switch sends a signal to the ECM. If the ECM is removed, the switch is basically doing nothing, and as best I can tell in those cases, the rest of the a/c system would continue on as normal. With the caveat that the V6 probably needs the relay jumpered, since the ECM trips the relay to control the compressor.
So in short, check YOUR wiring diagram, because results may vary.
One other question; where does the Idle Stop solenoid on the carb get its power from?
I see a wire (connector is gone) that is spliced into the pink distributor wire. This is from the factory, not something that was added. Could this be it? If not, what would that be used for?...
I have a non-ECM Quadrajet and a vacuum advance HEI distributor.
I have a torque converter lock-up kit from Monster transmission but have not installed it yet.
So just to make sure I'm clear on this; is this connector useless now that there's no ECM? Should I just cut it off and tuck the wires into the harness?
Cool on the Monster kit , the lockup is a great thing to have MPG wise . And as to the PS switch connector , if you have deleted the air conditioning along with the ECM then yeah , It's useless and can be eliminated .
PS , to Drew , there are so many different variations of these things across the 10 year run that your advice of always checking the wiring diagram for the year involved should be posted at the top of the electronics page
Last edited by OrangeBird; 07-04-2019 at 01:04 PM.
One other question; where does the Idle Stop solenoid on the carb get its power from?
I see a wire (connector is gone) that is spliced into the pink distributor wire. This is from the factory, not something that was added. Could this be it? If not, what would that be used for?...
And to answer this question , we'll need to look at a different wiring diagram .
This diagram shows the original wiring of the idle stop solenoid . It is controlled by the "throttle kicker relay which is (or was , in your case) controlled by the ECM . That pink/black wire was to provide the positive side of the relay's coil , the negative side of the relay's coil being switched to ground by the black wire connected to the ECM terminal labeled "E" . Looking at the throttle kicker relay you can see that the actual power that the relay is switching comes from the brown/white wire (which eventually becomes brown only) connected to the 10 A fuse labeled "C-H" , and that when the relay isn't being triggered by the ECM the A/C system can still command the solenoid through the light green wire on the relay labeled as being connected to the A/C system .
PS , these diagrams I'm posting come from a site called "Austin Third Gen" and are claimed to be for your 1983 third gen 305 carb equipped Firebird . Over the years I have found them to be mostly accurate , with the exception of a typo here or there , like where they incorrectly use the word "Transaxle" instead of the correct "Transmission" in identifying the TCC circuit .
Last edited by OrangeBird; 07-04-2019 at 12:50 PM.
Cool on the Monster kit , the lockup is a great thing to have MPG wise . And as to the PS switch connector , if you have deleted the air conditioning along with the ECM then yeah , It's useless and can be eliminated .
I have not deleted the A/C, nor do I intend to.
Is that throttle kicker just for bumping up the idle speed when the A/C is switched on?...
I have not deleted the A/C, nor do I intend to.
Is that throttle kicker just for bumping up the idle speed when the A/C is switched on?...
Ok , so , , If your keeping the air conditioner you'll have to either have that power steering cutout connector connected to a functioning power steering cutout switch , or jump it out by connecting the two wires together , for your A/C compressor clutch to operate . Of course with it jumped out it won't shut off the A/C with a rise in steering pressure .
Now as to the solenoid , Since the ECM is gone and can no longer control the throttle kicker relay , there really is no reason for that relay to be there . The A/C system will still want to control the solenoid though , and that can be accomplished by jumping the light green wire to the dark blue wire and eliminating the kicker relay alltogether , allowing the A/C's control of the solenoid without the needless (ECM removed) kicker relay . In function , turning the A/C on naturally puts a load on the engine , and the solenoid opens the throttle slightly in response to that increased load . The whole ECM / Kicker relay deal was to give the ECM a bit of control to slightly open the throttle whether the A/C is on or not , to try to avert a stall should the ECM detect a sudden RPM drop at idle .
Last edited by OrangeBird; 07-04-2019 at 07:22 PM.
Ok , so , , If your keeping the air conditioner you'll have to either have that power steering cutout connector connected to a functioning power steering cutout switch , or jump it out by connecting the two wires together , for your A/C compressor clutch to operate . Of course with it jumped out it won't shut off the A/C with a rise in steering pressure .
Now as to the solenoid , Since the ECM is gone and can no longer control the throttle kicker relay , there really is no reason for that relay to be there . The A/C system will still want to control the solenoid though , and that can be accomplished by jumping the light green wire to the dark blue wire and eliminating the kicker relay alltogether , allowing the A/C's control of the solenoid without the needless (ECM removed) kicker relay . In function , turning the A/C on naturally puts a load on the engine , and the solenoid opens the throttle slightly in response to that increased load . The whole ECM / Kicker relay deal was to give the ECM a bit of control to slightly open the throttle whether the A/C is on or not , to try to avert a stall should the ECM detect a sudden RPM drop at idle .
Thanks for the info. I wonder where that kicker relay is located...
Thanks for the info. I wonder where that kicker relay is located...
Well , now ya just ran past any info I can find in the wiring diagrams , and so I have no solid answer as to the location of the relay . If I had to guess , I'd look to the traditional third gen relay place , next to the master cylinder , and if its not there a general hunt under the hood may turn up where it is . Using the wire colors in the wiring diagram will help , the connector for the relay should have pink/black , light green , brown/white , dark blue and solid black colored wires on it .
What caught my eye in this thread is that you're not running the TCC Lock-up yet. While most of the time this isn't a real big deal, it IS a pretty big deal if you've still got your original 83 Tranny. The 83 tranny was found to be more susceptible to problems when the TCC function was disabled / removed. These were some of the earliest 700s and TCC function was more important to these Trannys compared to later / updated versions. If you've already got the parts,....... I'd make installing them a pretty high priority on your 'to-do' list !!
I removed my earlier scolding post , and will go with this instead ;
NINA , your post is in error . There most certainly is a relay controlling the idle stop solenoid on the OP's 1983 third gen , it's called the "Throttle Kicker Relay" in the diagrams both John and I have posted . This relay is controlled by the ECM , but rest assured the relay does , in fact , exist .
Perhaps you were thinking of the "Mixture Control Solenoid" , which is indeed controlled by the ECM with no relay in it's circuit , but the solenoid under discussion was not the Mixture Control Solenoid , it was the Idle Stop Solenoid , as shown being controlled by it's Throttle Kicker Relay in the above posts .
I would appreciate you editing your post to show the correct information here ......
Last edited by OrangeBird; 07-05-2019 at 04:51 PM.
Remember folks , we have a moral obligation to future third gen owners/readers here to get it right . Misinformation posted here will make this board about as useful in the future as equipping a turtle with a set of disc brakes .....
Last edited by OrangeBird; 07-05-2019 at 04:55 PM.
So what if I just ran a wire from the A/C switch wire to the throttle kicker solenoid. Wouldn't that energize it when the A/C is switched on, and de-energize it when the A/C is switched off?...
The only person that doesn't make a mistake is the guy that don't do nuthin'..........
So what if I just ran a wire from the A/C switch wire to the throttle kicker solenoid.
Would work - the AC circuit should carry battery voltage when active - but consider this; A relay is used on just above every electrical accessory for a reason.
If you remove the relay,...... rather than the GREEN AC wire simply being used as a "signal" wire,... you are going to be drawing voltage thru it to power the accessory in question. This accessory (Throttle Kicker ) isn't as power 'hungry' as many others ( electric fuel pump, fans, exterior lighting, etc.. ) so if the ONLY thing you are going to use that GREEN AC wire for is to feed power to the fast idle solenoid; you will probably be OK. ( Keep an eye on the Heater/AC fuse terminals, watch out for signs of overheating. )
Word of advise: if relays are removed from - or not installed for - the electrical 'stuff',......... BE SURE that you have a fire extinguisher in the car at all times !
P.S. Diagram I posted was for 85 Berlinetta, but Throttle Kicker info info is exactly the same for Coupe/Z28.
Last edited by John in RI; 07-05-2019 at 05:40 PM.
Reason: Heater/AC fuse
So what if I just ran a wire from the A/C switch wire to the throttle kicker solenoid. Wouldn't that energize it when the A/C is switched on, and de-energize it when the A/C is switched off?...
Looking at the schematic diagram , you would want to connect it after the A/C system's low pressure cycling switch , but before the power steering cutoff switch . The light blue wire between the two switches would be the place to ensure that the idle stop solenoid comes on when the A/C commands the compressor clutch , and remains on if the power steering cutout switch shuts the compressor clutch off . Then again , jumping the light green and dark blue wires at the relay socket would be the easiest path to take , provided the original A/C wiring (including the power steering cutoff switch) and the original idle stop solenoid wiring are still in place . Unplug the relay , jump the light green & dark blue at the relay socket , and done . Technically , if all the factory A/C and idle stop solenoid wiring is in place , you don't have to eliminate the relay at all if you don't want to , it will pass the A/C systems command on to the solenoid just fine (it'll just never pass any ECM commands since there is no ECM) . I just figure most folks who do the ECM removal project like to remove as many ECM associated components as possible (without negatively affecting any other circuits , of course) .
Remember , what John says is correct , Relays can't just be eliminated without careful consideration . In this case , you'd have no problem because of how this circuit operates . In operation , when the ECM decides the throttle needs a bump , it commands the relay coil , putting the pink/black wire's 12V on to the solenoid VIA the closing of the "Normally open" relay contact . Now when the ECM is not commanding the relay , when it's in it's de energized state (No ECM commanding it's coil to close the contacts between the pink/black and the solenoid) the solenoid is connected by the "normally closed" relay contact to the A/C system , allowing the A/C system to operate the solenoid without operating the relay (using the normally closed relay contacts as a pass through only) . Instead of the most common use of a relay , to control a high current device with a low current control circuit , this relay is allowing two different , independent , low current control circuits to control a low current device .
I hope that made some sense
Last edited by OrangeBird; 07-05-2019 at 06:08 PM.
Yeah, it makes sense. I just have no idea how much current that solenoid draws, so didn't know if it could be run from that A/C power or not. Kind'a looks like a relay is necessary though...
Yeah, it makes sense. I just have no idea how much current that solenoid draws, so didn't know if it could be run from that A/C power or not. Kind'a looks like a relay is necessary though...
No , a relay is not necessary , and my post explained why .
I don't know how I could say it any differently , in this case the relay is not for current draw considerations , it's to allow two independent circuits to have control over the same solenoid . When the relay is "at rest" (De energized) is when the A/C has control of the solenoid , and when the relay's coil is energized by the ECM is when the ECM has control . If the ECM never detects the need to kick the throttle , the relay is not active , and is simply passing the A/C's control signal straight through itself (as thought it was a straight piece of wire) to the solenoid .
Okay, I get it now. I really appreciate all your help...
Cool , I really am happy to help .... Even though I may come across as a gruff old fart sometimes I really do know the electrical aspect of these cars pretty well and try to help out when I can .
07-02-2019, 11:07 PM
We're on the same page now. When I saw this thread last night, I was thinking the same connector as you. With it being on the driver's side narrows it down to the switch I always forget about. 
And to answer this question , we'll need to look at a different wiring diagram .
Well , now ya just ran past any info I can find in the wiring diagrams , and so I have no solid answer as to the location of the relay . If I had to guess , I'd look to the traditional third gen relay place , next to the master cylinder , and if its not there a general hunt under the hood may turn up where it is . Using the wire colors in the wiring diagram will help , the connector for the relay should have pink/black , light green , brown/white , dark blue and solid black colored wires on it . 
