New daily driver help needed.....not a mustang but mustang drivetrain.
- Thread starter Wayne Waldrep
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Lol.... Come on y'all. I want the circuit completed so everything else thinks the compressor is turning. I've tried unplugging the compressor and obviously the switch inside the car does nothing then. I want to put something that won't burn the car down between the two wires on that compressor connector.So, remove the connector from the A/C clutch assy.
This discussion has honestly helped me find a couple discussion elsewhere that I would never have found without y'all so thanks. Stick with me on this and we'll get it i think.
The problem with your assumptions in this scenario is that even if you [complete] a circuit, the A/C still isn't simulating normal function. You have one or maybe even two pressure switches and without a wiring diagram, Lord only knows what else.
Everything else should think the compressor circuit is completed. What leads you to believe otherwise? The difference between positive and negative across the clutch coil induces the E-M field, but that field doesn't energize anything else or send a signal back. You can see that here:
That, of course, is for a fox, but hey... that's what we know, here.
That, of course, is for a fox, but hey... that's what we know, here.
You can simulate electrically the A/C being "on" all you want, but it will never simulate the load on the system, either from the power required to spin the compressor or the flow of refrigerant through the system.
If possible, I would hook up a set of gauges to the A/C system and tape it to the windshield and drive the car. The pressures may be normal at idle, but when driving down the road you may have higher than normal pressures building up in the system creating extra load.
The Grand Marquis also probably has ambient air temp sensors in the duct-work and in front of the car to measure outside air temp.
Did you mention if this vehicle has Auto A/C or Manual A/C? The electrical system is different for each system.
If possible, I would hook up a set of gauges to the A/C system and tape it to the windshield and drive the car. The pressures may be normal at idle, but when driving down the road you may have higher than normal pressures building up in the system creating extra load.
The Grand Marquis also probably has ambient air temp sensors in the duct-work and in front of the car to measure outside air temp.
Did you mention if this vehicle has Auto A/C or Manual A/C? The electrical system is different for each system.
I know I wouldnt be seeing the load by the compressor, but if i could bypass it by jumping the plug and it still did the jolting, I'd know for a fact it isn't inside the compressor.
What leads me to believe otherwise is that it has zero reaction with the compressor unplugged and not jumped.Everything else should think the compressor circuit is completed. What leads you to believe otherwise? The difference between positive and negative across the clutch coil induces the E-M field, but that field doesn't energize anything else or send a signal back. You can see that here:
That, of course, is for a fox, but hey... that's what we know, here.
See my above reply on bypassing compressor.
Good idea on the AC manifold gauges while driving. Not sure if i can accomplish that but i will see.
The car has the manual AC setup.
Can’t you just jump out the low pressure switch and unplug the compressor?
If you want, measure the resistance of the coil for the ac clutch and install an equal resistor across the two wires to the compressor
I can only relate to what my ‘00 GT 4.6 does, and the ac system is not that smart. Doesn’t really know if the compressor engages or not.
How good is your OBD2 scanner? Can it do live data?
Go to pid 106 (I think) which is “total misfires” it may not be that pid so search around. Display this and go for a drive. Turn the ac on and se if this is counting misfires. Sometimes it will count them but not enough to throw the CEL.
There’s other data you should look at as well when the issue occurs. Misfires, short and long term fuel trims, as well as o2 data. I’d go for a ride, get the situation happening and hit record and then go back and see if anything looks off
Go to pid 106 (I think) which is “total misfires” it may not be that pid so search around. Display this and go for a drive. Turn the ac on and se if this is counting misfires. Sometimes it will count them but not enough to throw the CEL.
There’s other data you should look at as well when the issue occurs. Misfires, short and long term fuel trims, as well as o2 data. I’d go for a ride, get the situation happening and hit record and then go back and see if anything looks off
My scanner doesn't give me that i don't think. That's why i took it to the professional who does. He put the second set of new coils on and watched the data. He said no misfires. But i don't trust him now so there's that.
Ok, not sure if this helps, but I found a webpage with the AC wiring diagram for your car. I hope it helps:
But to answer your question you posted about my previous post, I was suspecting the PCM might have a fault that upon receiving the signal to engage the AC system, was sending bad/wrong impulses to any vehicle feature creating your headache. It appears from the diagram, the PCM isn’t so involved in that system, although, lots of stuff is. Good luck.
AIR CONDITIONING – Mercury Grand Marquis LS 1998 – SYSTEM WIRING DIAGRAMS – Wiring diagrams for cars
AIR CONDITIONING A/C Wiring Diagram, Auto A/C for Mercury Grand Marquis LS 1998List of elements for A/C Wiring Diagram, Auto A/C for Mercury Grand Marquis LS 1998:(behind right kick panel, near door sill) g203(front of right fender) g101(front of right front fender apron, right side of battery)...
portal-diagnostov.com
But to answer your question you posted about my previous post, I was suspecting the PCM might have a fault that upon receiving the signal to engage the AC system, was sending bad/wrong impulses to any vehicle feature creating your headache. It appears from the diagram, the PCM isn’t so involved in that system, although, lots of stuff is. Good luck.
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Okay I got to do some testing today. First thing I did was drive the car with the radiator fan unplugged like you guys asked me to. Driving down the road with no AC or anything turned on everything was perfect. Turned the AC on with the blower motor on low and it still did the same jolting feeling as if something electrical wasn't working right. Turned the blower motor on high with the AC on....still the same thing.
Went home and plugged the fan back in. BTW, the car didn't run any hotter than normal because i didn't sit still with it.
Worth noting...thru all this the AC works perfectly. No grinding noise from the compressor. And even at idle, no weird running or jolting with the AC on. But you turn the AC on going down the road and you would swear you are about to walk home.
Next thing I did (with the fan plugged back in) I checked voltage with the car running with the AC off and I got 13.9 to 14.1 volts. I then turned the AC on and I still got the same voltage readings. Then I turned the blower switch to high and still got the same readings.
Didn't have time to check resistance on the compressor coil yet.
So unless I'm stupid (better not comment on that General...lol), I'd say there's absolutely no way it could be the radiator fan since it does it with it unplugged? Yes?
Thoughts on all this? Thanks guys!
Went home and plugged the fan back in. BTW, the car didn't run any hotter than normal because i didn't sit still with it.
Worth noting...thru all this the AC works perfectly. No grinding noise from the compressor. And even at idle, no weird running or jolting with the AC on. But you turn the AC on going down the road and you would swear you are about to walk home.
Next thing I did (with the fan plugged back in) I checked voltage with the car running with the AC off and I got 13.9 to 14.1 volts. I then turned the AC on and I still got the same voltage readings. Then I turned the blower switch to high and still got the same readings.
Didn't have time to check resistance on the compressor coil yet.
So unless I'm stupid (better not comment on that General...lol), I'd say there's absolutely no way it could be the radiator fan since it does it with it unplugged? Yes?
Thoughts on all this? Thanks guys!
So I am building a '70 F100 with a 2006 CV front suspension so I have a login to crownvic.net and mercurymarauder.net so I did some search and I think this answer is in this thread:
Hope it helps but I am not 100% sure as I have never owned one personally just cut one up for the parts.
Hope it helps but I am not 100% sure as I have never owned one personally just cut one up for the parts.
Thanks for the link. Amazing not one guy on there linked me to that article. That's exactly why i came here. Anyway, i read it all. No real resolution was stated. I do not have the surging and stop light weirdness though that they have. Mine is only at highway speed. I pushed the overdrive button and turned it off and it still does it even before going into OD. I'm saving the thread though and putting it in my possible things to look at. I just don't get the "only with AC on" that seems to be happening. One diagram posted above made it clear that there is NO signal back from the compressor. And with the compressor unplugged it does not do it. So something is seeing it plugged or unplugged.
"My 98 p71 also does this. Im guessing the extra load causes the tcc to unlock. When I datalog thats exactly what its doing, unlocking when the compressor initially kicks on then reapplies. Do you have any problems where it will almost die when coming to a stop then it revs and the car lurches forward?"
Might be what yours is doing. TCC = torque converter clutch solenoid.
For the most part the guys on crownvic.net are pretty helpful but the guys over the the Marauder site are way more technical.
Might be what yours is doing. TCC = torque converter clutch solenoid.
For the most part the guys on crownvic.net are pretty helpful but the guys over the the Marauder site are way more technical.
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