AC in the 86'

[86GmLsCoupe]

My ac in my Grand Marquis won't run. The problem all seems to come down the AC WOT relay. The original connector was pretty worn out so it was replaced 2 yrs ago and all of the wires were transferred over to the new connector one by one. The problems now are.

1. I don't know what the original was anymore (color, pin position, or amount of pins. I thought the original was a brown 4 pin one, but it seems there's one for the ECM that brown, though keyed differently.
2. I've tried about 3-4 Standard relays RY68's (5 pin), a black E5----- Ford one (5 pin), and a Ford brown one (4 pin).The black and brown Ford ones got the compressor on for a bit and then seemed to burn up. Also the relays seem to activate (they click) as soon as they're plugged in.

I tried going to the junkyard today figuring I'd just grab the ac relay and connector altogether and solder that in so I'd be sure I had the right relay and connector but they didn't have any older gm'c or cv's.

The clutch pressure switch is good, the TPS is fine, so I'm kinda stumped. I haven't been able to find any diagrams for the fender relays or their pinouts in my ford manuals, the EVTM, or my alldata subscription so any input would be useful. At this point I'd just go and wire in regular Bosch 30 amp and be done with it but I have no clue what each wire does. Any info would be appreciated, it's starting to get warm out again and I'd love to get the ac running. My wiring knowledge is pretty weak so please bear with me.

[gadget73]

Looking at my 86 EVTM, in order to bypass the relay for testing purposes, connect the pink/light blue to the black/yellow wire. If the compressor and all that runs, the relay is your problem. If it does not run, you got issues elsewhere. Let me know what you get and I'll see what I can do to point you in the right direction.

[86GmLsCoupe]

Thank you, I'm going give that a try tomorrow after work. I have an 86' EVTM but half the time I'm not sure what I'm looking for, plus since its an odd year and some things look different in the book. I tried out a different relay today, a Standard Auto RY46 and I got the same thing; idle adjusts, compressor kicks on for a sec, then stops, and the relay just clicks.

I got the RY46 by crossing the old relay's Ford # (E5SB4113) into Napa's catalog, getting the ECH AR240 #, and then crossing back into the Standard Auto catalog which brought up the RY46 which was not the part rockauto and standard lists (RY68). Either way, figured it was worth a shot. I also checked ground 505 by the pass. side hood hinge and it looks clean and tight. I'll get back to you tomorrow and let you know what happens. Thanks again.

[86GmLsCoupe]

Alright, I did the test like you said and jumped the P/LB wire to the BL/Yellow and the compressor kicked on for a few seconds and died. This was sort of good news since it confirmed it wasn't the relay. I popped the old black Ford relay in, jumped the clutch cycling switch and it worked continuosly, even when changing to defrost, hi/lo, ect. So... it turns out it is the clutch cycling switch. I ordered a Season's 134A one and should have it tomorrow. After that I think it'll be good again, but will know for sure when driving around. So in my car the relays are as follows:

Green-Fuel Pump
Brown-ECM
Black-A/C WOT

Thanks again, working AC is such a good thing to have.

[gadget73]

Did you verify you have proper pressure on the low side of the AC system? I think the stock switch runs like 25-45 psi, off at 25, on at 45. It is adjustable but if the pressure is way off, its not gonna run.,

[86GmLsCoupe]

I had it running for a few but didn't want to keep it going until I get the new switch installed. The switch was the only ac part besides the condenser that was not replaced so it's prob an r12 one, though the car was converted in the mid nineties so who knows. Last summer we had one of those charge kits with the gauge on it and it showed it in proper range (around 80% of r12 charge) and the switch was I guess somewhat adjusted. Even with all of that, the ac was still pretty weak (50's-60's F) when it was working. In the time I did have it on, it seems much colder and consistent. I guess I never realized the ac cycling switch would energize the WOT relay so I didn't look into it before. I'd like to test the pressure again but my Dad's not really a Ford guy that doesn't like working on my car to much, and doesn't want to keep messing with the schrader valves. I didn't trust the switch two years ago and should have just changed it then, but at least with the new one, if the relay energizes, then I know the pressures have to be off. I was very doubtful the ECM was going to be the problem in this case.

[Lincolnmania]

it is possible that it needs to be charged again....there might be a leak

[gadget73]

The pressure switch is not tied into the WOT relay. The power does go through both, but the pressure switch just breaks the circuit directly ahead of the compressor, it does not activate the relay. The only thing that can activate the relay is the ECM.

[86GmLsCoupe]

Ahh, I thought they were tied directly together because they relay stopped energizing the second I jumped the clutch switch and I've been messing with this off and on about 2 years now. I did get the part today, a Four Seasons #36676 (R134A retrofit) so I guess I'll just sort of see. I'm pretty sure the current is and adjusted r12 one I was told to just leave in. I know Ford's don't like you throwing money at them but I'm kind of desperate. That car is miserable without ac, especially when both pwr windows went. The big test now will be seeing how the AC is when driving now that I can get it to stay on at all. Before, feathering the pedal was kicking the relay on. I still have no clue why the ECM would be trying to activate it. The car has no codes (besides smog), the wiring is all decent, and even has a newer TPS. I'll get back to you with what happens. Also may check the pressure like Scott said if it short cycles. Thanks again for the information, let you know what happens tomorrow.

[86GmLsCoupe]

I just put the new clutch cycling switch and now I can get the compressor going and stay running. It's short cycling; on 3 secs, off 3 secs so the I have to check the charge but this is a big improvement for me. The compressor won't kick off when the idle is raised unless wot so that's a good thing to. My Dad's not sure if he has R134A gauges so would a bottle with the gauge on it be alright or should I just pick a set up? I definitely don't want to half ass it or do the wrong thing. IIRC it should be 80% of the original R12 charge right? I don't know the clutch switch is affects the WOT relay on my car, but with the new one its not energizing anymore.

[gadget73]

Decent manifold guages would be better than just a can. Those will really tell you whats going on with the whole system. I seem to remember going through a couple of cheap replacement switches on yucatec's car, they would do the same thing you describe. I don't remember what the ultimate solution was, but I want to say it involved an OEM switch, or just a good used one with a tweak to the pressure screw. Scott can probably fill you in on the details of what ended up being done to fix the short cycling issue.

Of course,before jumping to any conclusions you really need to know what the system is doing for pressure. Might need to hot wire the switch to get a real idea.

[86GmLsCoupe]

I think I'm going to end up buying a set of manifold gauges so I do it the right way plus I'll end up needing them for our 90 Sierra's AC soon enough. I honestly couldn't say what the old switch was; A tweaked R12 or R134A since it had been converted once before in the nineties. When I replaced everything in 06', my Dad said leave it and I probably should have changed it then. Either way it's working now and the new switch has a retrofit label right on it to avoid confusion. Four Seasons is a good brand so I'm not to concerned about quality. I'm big with oem parts but at this point I'm so frustrated with it I don't care what brand it is so long as it works.

The main thing now is to get the charge right so it runs properly. I'm not using it now so I don't kill the compressor. The one thing I'd like to know is are those charge cans in the store any good, especially Arctic Ice and those similar? I read the bottle and it says it has a "system safe sealant" and I thought sealers weren't the best idea. Thanks again.

[Lincolnmania]

no sealers
if you wanna find leaks use 134a with leak dye in it.....not to be confused with tye dye

[gabegt90]

I just put the new clutch cycling switch and now I can get the compressor going and stay running. It's short cycling; on 3 secs, off 3 secs so the I have to check the charge but this is a big improvement for me. The compressor won't kick off when the idle is raised unless wot so that's a good thing to. My Dad's not sure if he has R134A gauges so would a bottle with the gauge on it be alright or should I just pick a set up? I definitely don't want to half ass it or do the wrong thing. IIRC it should be 80% of the original R12 charge right? I don't know the clutch switch is affects the WOT relay on my car, but with the new one its not energizing anymore.

yes r134a is 80% of the stock r12 spec. stock spec of r12 is 3 lbs
I just had my co worker recharge mine last week 2 lbs 13 oz

[86GmLsCoupe]

no sealers
if you wanna find leaks use 134a with leak dye in it.....not to be confused with tye dye

I gotcha so then the Walmart/Autozone recharge bottles with the gauges are a bad idea then since they have a sealant. My Dad's friend popped one my car last year and I think put a tiny bit in. Also from my reading the reg has PAG and I'd need ester oil but I'm not sure on that one. The system is all new besides the condensor and the lines have the barrier hoses so would I still use the ester oil lubricant.

Also, Thanks for letting me know the proper weight, I forgot to ask that as well.