1973 valiant 318 car stalls when compressor comes on

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1973 valiant

1973 valiant
Joined
Oct 16, 2020
Messages
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Location
Raleigh north carolina
I have a 73 valiant 318 with ac when I turn.the ac on the car stalls plus the power wire from the alternator gets hot I just got the car and the harness connector was burned up I ran and repaired the wires after that it started overcharging so I changed the regulator and it is now charging 14.5 volts but when I tried to turn the AC back on car stall dead in it's tracks even raising the idle I'm new to a body mopars is it possible the compressor is shorted out and plus should the idle kick on higher when ac is on? I do not see any type of stepper motor for the ac anything would help thank you from Nick in Raleigh nc
 
When you say "harness connector" are you referring to the WHITE thing in there? Bypass that whole mess!!!! That is a factory disaster that should have been federally recalled!!!!

There's a few possibilities.........

The compressor clutch magnet may be shorted. Research how much it should draw, "rig" it up with clip leads and MEASURE THE CURRENT with your meter!!!!

It could be the idle is too low RPM, and or that the idle mixture is way wrong and causes the engine to sag, and check timing while doing so as well

It is possible the compressor has an internal problem AKA worn out metal filings dragging, about to seize, or that the system is overcharged

Page 24-35 of the 73 shop manual which you NEED TO GET if you don't have. Download it free from MyMopar

clutchdraw.jpg
 
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When you say "harness connector" are you referring to the WHITE thing in there? Bypass that whole mess!!!! That is a factory disaster that should have been federally recalled!!!!

There's a few possibilities.........

The compressor clutch magnet may be shorted. Research how much it should draw, "rig" it up with clip leads and MEASURE THE CURRENT with your meter!!!!

It could be the idle is too low RPM, and or that the idle mixture is way wrong and causes the engine to sag, and check timing while doing so as well

It is possible the compressor has an internal problem AKA worn out metal filings dragging, about to seize, or that the system is overcharged

IMG_20201014_174630870.jpg
 
BTW you can delete duplicate posts. Look for the "thread tools" right side under the title of the thread.

Also if you use the quoted reply feature be sure to type outside of the text that shows up like this.

[ QUOTE="67Dart273, post: 1973173921, member: 17025"]....[/QUOTE ]

It is ok to type before the [ or after the ] but not between them.

Lastly you can delete a post in a thread, look for the delete button under the post you want to delete.
 
Regarding photo from post 3.

NASA we have a problem.

....and I addressed that in post 2 LOLOL. We can thank Redfish for initially pointing out the problems with the "white connector."
 
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I bypassed the connector and re connected the wires in line I'll research and check the draw on the compressor and I will re set the adjustment on the carb wanted to ask with Plymouth s does the carb have some kind of set up to raise the idle when the ac is activated looks like the carb was replaced I know I have to get some service manuals thank you so much I'm a fish out of water when it comes to vintage mopars but I'm so stoked to own this car thank you glad I found this site I have alot to learn
 
You should of seen the tape that was wound up and hiding this mess I believe the freyed up wire at the ends I suspect came from the alternator wire ?
 
BTW you can delete duplicate posts. Look for the "thread tools" right side under the title of the thread.

Also if you use the quoted reply feature be sure to type outside of the text that shows up like this.

[ QUOTE="67Dart273, post: 1973173921, member: 17025"]....[/QUOTE ]

It is ok to type before the [ or after the ] but not between them.

Lastly you can delete a post in a thread, look for the delete button under the post you want to delete.
Thank you I'm getting used to this site
 
Ok @1973 valiant

I think I know what is happening with your replies...

Don't use the "Quote" or "Reply" buttons below a post.
Just go to the bottom of the list of posts and start typing

If you want to quote something highlight it and then hit the "reply" that shows up just under the highlighted text.
 
Thanks I think I got it now sorry about that I see alot of ads I had to delete out I think was covering the bottom the replies let me know if it's correct
 
I bypassed the connector and re connected the wires in line I'll research and check the draw on the compressor and I will re set the adjustment on the carb wanted to ask with Plymouth s does the carb have some kind of set up to raise the idle when the ac is activated looks like the carb was replaced I know I have to get some service manuals thank you so much I'm a fish out of water when it comes to vintage mopars but I'm so stoked to own this car thank you glad I found this site I have alot to learn

If it did it will be a large obvious electrical solenoid right at the throttle linkage similar to this

MD2397_thumb.jpg
 
I have that same 2 brl. and intake on my 273. It came off a 73 valiant with factory p/s and a/c. it never had a throttle kicker on it. If the 318 was tuned properly it made enough horse power at curb idle that additional load from the compressor was hardly noticed. Low timing along with todays pizz poor fuel? a/f mix wrong due to a vacuum leak? Root question... How well does it run without a/c engaged?
 
It runs very well I adjusted the carb and tuned the car up plugs wires cap and rotor it has a electronic ignition on it I haven't checked the timing on her but she pulls very well it has 19 inches of vacuum at idle the system looks like it's R12 I know that the battery lead from the alternator gets very hot when I put the ac on then the engine stops in it's tracks I think the compressor may be shorted thank you redfish I think that's why that connector burned up possible I'm new to this car and Mopar but I'm having a blast on this old valiant
 
Don't just guess MEASURE it. There is NO excuse in this modern world to NOT have a multimeter. You can buy them several places "in town" or over the internet. 50 bucks can buy a really decent one, HorridFreight a few dollars can buy a cheap but useable one. YOU NEED a multimeter if you are going to work on these old girls

And, you may be wrong.......are you sure the alternator wire ONLY gets hot when the AC compressor is on? Seems like it would take a long time to do that, and if it heated that badly, there would be fuses blowing or "wire smoke." Does the compressor clutch wire get hot? it is much smaller.

MAYBE the reason the alternator wire is getting hot is some other reason.

Does the compressor clutch even engage? Does it operate when the engine is running? You can HEAR the clutch engage, "loud click" and if the engine is running, you can SEE the compressor run (look at center of pulley hub)
 
I have that same 2 brl. and intake on my 273. It came off a 73 valiant with factory p/s and a/c. it never had a throttle kicker on it. If the 318 was tuned properly it made enough horse power at curb idle that additional load from the compressor was hardly noticed. Low timing along with todays pizz poor fuel? a/f mix wrong due to a vacuum leak? Root question... How well does it run without a/c engaged?
Don't just guess MEASURE it. There is NO excuse in this modern world to NOT have a multimeter. You can buy them several places "in town" or over the internet. 50 bucks can buy a really decent one, HorridFreight a few dollars can buy a cheap but useable one. YOU NEED a multimeter if you are going to work on these old girls

And, you may be wrong.......are you sure the alternator wire ONLY gets hot when the AC compressor is on? Seems like it would take a long time to do that, and if it heated that badly, there would be fuses blowing or "wire smoke." Does the compressor clutch wire get hot? it is much smaller.

MAYBE the reason the alternator wire is getting hot is some other reason.

Does the compressor clutch even engage? Does it operate when the engine is running? You can HEAR the clutch engage, "loud click" and if the engine is running, you can SEE the compressor run (look at center of pulley hub)
 
You can also transfer all or part of one of your posts into another one of your posts .
You can go to say post 20 and hit EDIT, then highlight whatever part you want to transfer, by left clicking and dragging the highlight over the entire part that you want to transfer. Once it is highlighted, right-clic and a menu will drop down. Go down to "cut" and hit it. The program has now cut it out and cached it.
You should see a flashing line at the top left of your post, indicating where any new typing will occur; ignore it, and left clic on any dead space, and that post should be empty.

Next go to the post you want to transfer this to, Say post 19,and click on EDIT
Once in, scroll down to where you want to put the cached part, and left clic to get the flashing starter. Right clic for the menu, and go down to "paste". Left clic on that and the program should install whatever last thing you successfully cut out, right next to the flashing starter.

If the post you cut from, failed to delete, you can now go to the delete button and get rid of it that way.But if there is a part you left behind, and want to keep, then clic on "save changes"

It sounds complicated but after a couple of times you may using it a lot. You can edit as many times as you want to.
However;
If you state a "truth", and a day later, later find out you were wrong, it is considered "poor etiquette" to edit it out. Instead Write "EDIT" at the bottom, and make the correction in the edit. This will keep the "edit police" off your back.
If you look at the bottom RH corner of this post, you will see "last edited at such and such a time" . That's because I tend to add stuff to posts sometimes long after the original post went up. This post is one of those. You can look to the top left and see I originally posted this at "X minutes ago" . later it will have a time-stamp on it. You can compare those two and see how long I've been editing,lol. Hyup; I'm a really slow typer and I make a lotta mistakes.
 
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Am I replying in the rite spot in this box sorry making alot of mistakes i just went to check the car and now I have other issues the passenger window fell down now lol the plastic track clip fell apart on the bottom so it's alot of things going on with this valiant but I thank everyone for there replies let me get a meter and start from scratch
 
These are the ohms I am getting from the compressor ran one wire to the coil and ran the other wire to the positive battery View attachment 1715615119
Sorry I have no idea what you mean, there. If you are going to check resistance of the compressor clutch, connect the meter to the two disconnected clutch wires right at the compressor. "Positive battery" is not in the mix

NEVER hook any external power in with a resistance check.
 
I took the compressor wire off put the meter on continuity put one wire on the wire and the other wire to the ground and in getting continuity wouldn't that tell me that the coil in the compressor is shorted out ,?
 
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