Cooling fans and AC

[Evildeli]

Took the D out for a spin. AC was cool (not cold) and the cooling fans didn't come on. Car didn't overheat, but I knew something was wrong. So I got home as soon as I could. I tapped the fan fail fix (hervey's) and nothing changed, so I fiddled with the plugs and found they were loose. As soon as they made their connection, the cooling fans came on, but the ac didn't get colder and the compressor didn't turn on. I gave it about 30 minutes and started the D up again and just let it sit in the garage. The car didn't overheat, but the cooling fans didn't come on ( I would have figured it would).The ac was cool but not cold. I know it's just sitting but it gets me nervous. I replaced the fan fail with the original circuits but the fans still didn't turn on. So, am I panicking for nothing, or something wrong here? I'm afraid the ac is low again, but I also think the fan fail might be dead.

[Bitsyncmaster]

I've seen the diode in the relay compartment harness cause the cooling fans not to come on with the AC. Usually just a bad connection at the diode. But that would not stop the compressor from running. It's really bad if the compressor runs and the fans don't. You get very high pressures and it may pop the safety relief valve or a hose.

Do you still have freon in your system?

[Evildeli]

I'm afraid the freon might be low. I've fought the ac for so long, I was hoping by replacing everything this issue would be over. So far the compressor has not come on today, so I guess that's good. I was just thinking that it wasn't coming on because of the fans not coming on. When I reconnected the fan fail and the fans came on, I expected the compressor to come on too, but they didn't.

[Bitsyncmaster]

I had problems with slow leaking when I converted mine. Turned out to be the short hose going from the condenser to accumulator (I hope it's stopped now). So far so good.

[Evildeli]

Cause I'm a glutton for punishment I took the D out again and the fans didn't come on at all. The compressor didn't either, but it's bad if the compressor comes on without the fans, right? Once again the car didn't overheat, but the ac wasn't blowing cold. I was thinking my fan fail fix isn't working. I put a call into Hervey to see if he could help. Gotta wait for his call back. Am I on the right track? Or is there something else that is preventing the fans from coming on? Now I'm used to the fan fail fix when the fans turn on and off. If I go back to the original setup, how do the fans act?

[David T]

You have TWO problems. The cooling fans aren't running and the A/C isn't working. Get the cooling fans running right first. When the motor is running touch the two wires together at the otterstadt switch. If that doesn't get the fans going you will have to find out why. Once you have the fans running try the A/C. It should start the fans up in MAX or NORM. If it doesn't you are probably low on refrigerant.
David Teitelbaum

[Evildeli]

Are you referring to part 100816 -THERMOSTAT SWITCH (OTTERSTAT) (http://www.delorean.com/store/p-6348-thermostat-switch-otterstat.aspx)? Let me see if this is what to do;

1. warm up car
2. unplug wires to otterstat, use wire to complete connection- fans should kick on
3. turn ac to norm or max to see if compressor runs

Now will the fan fail fix try to interrupt this bypass, or should I unplug it and put the old circuits back in for this test?

[Bitsyncmaster]

Are you referring to part 100816 -THERMOSTAT SWITCH (OTTERSTAT) (http://www.delorean.com/store/p-6348-thermostat-switch-otterstat.aspx)? Let me see if this is what to do;

1. warm up car
2. unplug wires to otterstat, use wire to complete connection- fans should kick on
3. turn ac to norm or max to see if compressor runs

Now will the fan fail fix try to interrupt this bypass, or should I unplug it and put the old circuits back in for this test?

Jumper the otterstat first. Then when you turn the key to on your fans should run. If not you need to find the problem. After you get the fans running with the jumper, you can turn the AC on. Did the compressor turn on? Only when the compressor is running will the fans run unless the fans are turned on by the otterstat.

I don't think you even need to run the engine for these tests.

[Evildeli]

Thanks for the help guys. John Hervey called me back (on memorial day, non the less!) and he walked me through everything. He helped me figure out how to read two different voltmeters (yeah, I'm that much of a noob) and we talked about the otterstat test . My phone died, so I did that test without him, but just like him, and you guys said to do it. Sure enough the fans came on. I called him back and he confirmed I need a new otterstat. Lucky for me he sells those too. And then we talked about the cars for a while. I know people have opinions about him, but I tell you this, a vendor who goes out of his way to help someone on a holiday is just a bad ass, and he just went up a notch in my book. You guys rock too!

[Evildeli]

Well, I got the new otterstat! Good news is it wasn't the otterstat. After I replaced it, and the coolant I dropped, nothing changed. The compressor still wouldn't come on, and the fans wouldn't come on unless I bypassed. So I bought an r-134a kit and started charging. It took about about 75% of a 12 oz can nothing changed. So I turned the car off and spent 30 minutes going through the car again with a voltmeter with the same results. So I started the car back up and continued charging the ac and then the fans finally came on at about 85% of the can. At around 90% the compressor finally started cycling. I went about half of second can and some dye before stopping. At that point the gauge was reading at around 45 pounds in 85-90 degree weather. So of course this means that my ac problems still continue. I did notice that before I started charging the ac, the low side port had dye already, and it looked fresh (even before I added new dye). When I get some time I gotta do the bubbly water test to see if the leak is coming from the valve.

[Evildeli]

Cause I can't just leave things alone, I turn on a UV light and went through the car. I found some fresh dye coming from the connection from the evaporator to the dryer, and I found some fresh dye coming from the high side hose to the condenser. I tried to see if I could tighten those connections more, but they felt pretty tight and they're real hard to get to, so if those are my main spots I'm gonna have to take it to a mechanic to do.

Anyway, I started the car up, and although the compressor and fans were cycling, the gauge was at about 25 pounds. So I let it run for a little with the ac on max and then added some more freon back in until the gauge hit around 35 (when it get up to 35, the fans and compressor just stayed on). This time I took the car for a spin, and when I got back I checked the pressure again. This time it said 40. So I'm assuming that the pressure changes if the car gets hotter and that I may have over charged the system this morning, which could explain the dye coming from 2 spots. I'll probably still take the car to the shop next week to see what results they get.

[82DMC12]

After you replaced those A/C parts, didn't the mechanic who refilled your system put a vacuum to it? He would have caught the leaks then and that's the time to fix them.

If you opened the system up, lost pressure, fixed stuff, then refilled without pulling a vacuum, then I'm sorry to say but you deserve whatever you get! AC work is not for people to do at home (correctly).

Andy






Cause I can't just leave things alone, I turn on a UV light and went through the car. I found some fresh dye coming from the connection from the evaporator to the dryer, and I found some fresh dye coming from the high side hose to the condenser. I tried to see if I could tighten those connections more, but they felt pretty tight and they're real hard to get to, so if those are my main spots I'm gonna have to take it to a mechanic to do.

Anyway, I started the car up, and although the compressor and fans were cycling, the gauge was at about 25 pounds. So I let it run for a little with the ac on max and then added some more freon back in until the gauge hit around 35 (when it get up to 35, the fans and compressor just stayed on). This time I took the car for a spin, and when I got back I checked the pressure again. This time it said 40. So I'm assuming that the pressure changes if the car gets hotter and that I may have over charged the system this morning, which could explain the dye coming from 2 spots. I'll probably still take the car to the shop next week to see what results they get.

[Bitsyncmaster]

Static pressure (AC turned off) will change with the temp it is at. But with the AC running your low side pressure should run 25 to 40 PSI as the low pressure switch turns the compressor on and off. You really can't determine the correct freon charge just looking at the low side pressure.

Sounds like you have many small leaks. You probably need to find a good AC shop and get a complete overhaul of the AC system. New hoses, accumulator, orifice and system flush are normally required to convert from R12 to R134a.

[Evildeli]

Deserve what I get?..Uhm, okay. :confused: I converted to r-134a by replacing compressor, dryer, hoses and such. This was after spending time replacing an evaporator and having places like DMCFL look at the system with no luck. After replacing everything else I took it to a mechanic who vacuumed and charged and found the new evaporator was bad. So I replaced it, and then had them vacuum and test again and they only found the schrader valve bad. They replaced it, then charged and gave me a clean bill. Obviously I still have a leak, which is why I'll take it back to have them check again next week. I can save some money and do some tests at home too, though. This forum is for people who want to so some work on their own, and there's no reason to criticize for asking for help up here.

[David T]

I say concentrate on getting the cooling fans operating correctly before playing with the A/C. If you have A/C leaks you can't fix them by over-tightening the connections. All that does is damage the lines and fittings. The connections must be taken apart, cleaned, straightened if necessary, a new proper seal installed and then properly tightened. If you had the work done by a shop you should not be messing with it. I know if it was my shop and you came back after messing with it I would have a hard time trying to cover any problems not knowing what I did wrong and what you did to it.
David Teitelbaum

[82DMC12]

I'm not saying you shouldn't save money and fix stuff you can fix at home. That's half the fun of ownership. But air conditioning is something that unless you have the proper tools (and maybe you do, but it doesn't sound like it) you cannot repair the A/C without the help of a competent mechanic who DOES have the tools. A/C charging and alignments are the two things I will not even try to do because I don't have the tools. I'd rather pay someone who is an expert to do it right ONE TIME!

The shop I go to vacuums the system down for one HOUR. If you have leaks like it sounds like, it doesn't appear they are vacuuming long enough. They should be able to find this stuff and fix it the first time. It's not rocket science but you have to have the right tools and take the time to do it right.

You said you are filling up the A/C system with those kits you buy at the auto parts store. There's a huge market for that stuff which panders to people who would rather band-aid than fix, do things on the cheap, etc. Those kits don't pull a vacuum which is why I assumed you never pulled a vacuum, and anyone who does that, frankly shouldn't be surprised their A/C doesn't work again in a few weeks.

Instead of blindly topping off your A/C with kits, I think you should take it back to whoever has been doing the work and have them fix it right. I know people who fix A/C and they say while it's possible to get close by just adding a little and watching the pressures, the only way to really optimize the system is to totally vacuum it down, then fill it with the correct # of lbs freon.

Good luck, and I hope you get it straightened out.

Andy

[Evildeli]

I'm not pretending I understand AC which is why I'm up here asking questions, and I've had so many mechanics work on my ac. I was also under the impression that getting it done right meant I wouldn't have to do it more than once, and yet here we are. I've overtightened things before, and I've learned that lesson. In this situation, all I've done since bringing it to the shop is add a new otterstat and then try to charge the system with freon. I may have over charged though. The spots where I had dye come out were hard to get to, and I'm not interested in breaking anything cause I don't have the right tools, and so the mechanics know I haven't tampered too much. I believe in full disclosure when paying for someone else to work on my car. So I think we're all on the same page here. As soon as I can I'm taking the car back to the shop to have them vacuum and charge and test the ac again.

[Evildeli]

Just to give you guys an update, the new mechanic took a look at the AC and believe (drum roll) the condenser needs to be replaced. I'm way too green to change that myself, and I don't wanna deserve what I get :rolleyes1: so I'll have the new mechanic take care of that for me. How long does it take to replace the condenser. I know the radiator has to come out.

[jmrydholm]

Ugh, my A/C is also dead as well. The compressor used to spin, but since I got the car back, it won't even turn or cycle; even with the switch set to Max/Normal. I'm thinking my freon is totally gone. I still have the R12 system. Is it a *must* to convert to R134a?? I believe one of my relatives has some non-rusty cans of Dupont refrigerant sitting around, so if I can have a licensed HVAC or mechanic recharge it, will they? I don't think I've ever even touched the A/C as I've never needed it until I moved to Missouri. I was miserable when I drove her home, I had to wring my shirt out last week. Not cool (no pun intended!) Where should I start?

[stevedmc]

Just to give you guys an update, the new mechanic took a look at the AC and believe (drum roll) the condenser needs to be replaced. I'm way too green to change that myself, and I don't wanna deserve what I get :rolleyes1: so I'll have the new mechanic take care of that for me. How long does it take to replace the condenser. I know the radiator has to come out.

Do yourself a favor and get a condenser from Hervey. His are larger than the NOS units DMCH is selling and will help provide better cooling.

[Grover]

Ugh, my A/C is also dead as well. The compressor used to spin, but since I got the car back, it won't even turn or cycle; even with the switch set to Max/Normal. I'm thinking my freon is totally gone. I still have the R12 system. Is it a *must* to convert to R134a?? I believe one of my relatives has some non-rusty cans of Dupont refrigerant sitting around, so if I can have a licensed HVAC or mechanic recharge it, will they? I don't think I've ever even touched the A/C as I've never needed it until I moved to Missouri. I was miserable when I drove her home, I had to wring my shirt out last week. Not cool (no pun intended!) Where should I start?

Check your low pressure switch first. Mine failed completely and therefore never turned the compressor on.

[jmrydholm]

Yeah, I love Hervey. :cool1: (In a platonic, manly beer-and-pretzels kind of way!) He's a good guy. Half of my car's internal organs and guts is from DeLoreanAutoParts.com. I also used his water pump for the antifreeze.

[Evildeli]

I've already replaced the rest of the AC system with all Hervey's parts. To change to DMCH now on the last part probably wouldn't be smart. I'm just waiting on an estimate from the new mechanic before ordering the parts.