I got my previous A/C issue fixed; turns out it was a dual problem, a bad compressor clutch coil (replaced), and cut wires to the ambient air sensor (repaired). The A/C has been working fine, I thought, until yesterday morning.

I was at the drive through early in the morning waiting on my Egg McMuffin, when I noticed the windshield starting to fog up a bit. Thinking it was because my window was down, I kicked on the defrost. Big mistake, because it fogged the glass up so bad I had to wipe a spot off with a napkin. Uh oh, I think, let me run back to the house and switch cars, but when I started driving the cold air came back and it all cleared up. I drove it to work with no problems, but this morning I went through the same problem, and it cleared up after I started off down the road. Has anyone seen this before?

A possibly related problem to note; the display on the tach showing the outside temp isn't reading anything now, there is nothing showing. When we fixed the car last week, it was reading low at first, but after a short while started reading the true outside temp and was working fine until yesterday. Now nothing, no temp, and when I push the button to change the info, nothing shows at all. I think I'm going to grab a tach from a wrecked Mini near me, but I'm wondering if it might be related.

 

Two thoughts come to mind...


1 heater core.. Did the fog smell sweet? Does it get worse with the heat on...?

2 blocked drain tube... Allowing too much water to sit in the evap box.

 

Auto or manual temp control?
On the auto, the little red thinggy on the dash is a sensor that can change the blend of warm/cold air (blend doors) to try to matain a steady temp....and add to it the ac is not as effective at low rpms...especially if the radiator fan is not working 100% (low speed fan issue).

 

Definitely check low speed fan operation as a first step. Though curious as to where you are that the engine would be at 221F (low speed temp kick-on point) in the morning.

 

Uuuuuh.. North America? Have you seen the temperatures this week? My car hits full 220 in about 10 min of driving each morning.. (Well, that is unless I hit sport mode to drop everything down a bit.. (180.. EOT 200degF).

 

Gonna have to look at how you check the low speed fan operation. The motor shouldn't be running that hot, it's only been in the low 70's at 6am and it's only about 1/2 a mile from my house. Tomorrow morning I'm going to check it when I first start the car, at the drive through, later one with the windows up... see if I can pin the activity down. Gonna hook up the OBD2 adapter and see what the gauges show, too.

EDIT: Just dug up my OBD2 adapter and plugged it in. Sat with the car in idle for about 5 mins while I got everything set up; no cold air from the vents. Revved it up a few times, it felt like there was a bit of cold air coming out. Took it out for a drive and got lots and lots of chilly air. So it's an idle thing, it seems.

On a side note, what should my water temp be? Looks like it's hanging out in the low 200's while I was at idle, it maxed out about 210 while I was driving.

 

One of the purposes of the low speed fan is to suck air THROUGH the ac condenser... Which is mounted to the front of the rad....no airflow means the condenser can't work very well...that is why you home ac unit has a huge fan...fan stops....no ac....when you start driving you can mask the issue....
But rpm do help the compressor build more psi....

 

Well, I ordered a Dorman Fan Relay kit, I'm gonna assume it's the likely culprit. The low speed fan definitely isn't working; on the way home from work tonight I got stuck for almost 10 mins behind some idiot in the drive through who decided to order SEVEN individual orders; by the time I pulled up to the window, the Mini was overheating and smoking. I grabbed my bag and cruised the few blocks to my house keeping the RPM's down and the wind speed up. The temp went down as soon as I started moving, but I think I'm going to park the car until I can install the fix.

 

The high speed SHOULD have turned on to prevent the near overheat you had...
Sounds like you have zero fans..most common cause is a blown fuse from the PS fan...on pre 2005 cars...the PS fan could seize...and blow a fuse...resulting in zero radiator cooling fans....so check the fuses first....

 

Nope, the high speed fan works, it's just like it doesn't want to work right. It should have kicked on while I was sitting at the drive through, but didn't. When I got home a few mins later and shut the car off, it was running. When I had the car at idle the other night for a few mins and had my OBD2 connector hooked up, my coolant temp was about 205 degrees, got up to about 210 while I was driving. It's got a new thermostat in it, so that shouldn't be the problem.

Parking it for now, gotta work the next few days and by then I should have received the relay kit and have time to troubleshoot. It's strange driving my '12 Charger after driving the Mini for a few days; the Dodge is big, a smooth ride, quiet unless I'm on the pedal hard. In the Mini I can feel every bump on the road. It's not jarring, but with the low profile tires on the 18" rims, I feel everything. And in the Mini, I have this overwhelming urge to take every corner as fast as I can, lol.

 

Update:

Ok, got the Dorman kit installed, reinstalled the fan back on the car... and it's not kicking in. I monitored the temp while it idled in the carport, and when it got close to 240 I shut it down. The fan never kicked in at all. I know the fan works, I put 12v to it while it was out and it spun up.

How do I troubleshoot this? Is there anyway to test the signal to the fan? Anyone have any idea what might keep it from turning on at this point?

 

Well,

Its either - and input issue (switch).. the wires.. the controller.. /relay... the wires...

If you give me the details year/options I can take a look at some wire diagrams..

 

2002 R53, auto air.

 

Ok, a few more questions...

Did you square away the tach display issue?

Is this somehow related to the power steering/fan recall/campaign at the dealer?

I looked at the diagrams and they are pretty simple.. what's your electrical skill level? do you have a meter and or a test light? Did you check fuses yet?

 

The tach display is still blank. The rest of the tach is working fine, though. I think I'm going to get another tach, but waiting to spend the money after I figure out how much this is gonna cost to fix.

I have no idea.

Skill Level Pro, I have a degree in electronics and used to troubleshoot/repair weapons systems and space shuttles. Maybe Rusty Pro, because I just realized that I haven't checked the fuses yet.

EDIT: Well duh, the 5A fuse was blown. I had checked it before I started the resistor replacement, but I do recall getting a spark at some point when I was messing with the wiring before I disconnected the battery. Troubleshooting 101 should have made the fuse one of the first things I checked, but at least a member had sense enough to ask me if I had checked. Thanks Dan! Too late to check it out now, I'll see how it runs tomorrow.

 

Since the fuse was blown....
I will blow again....
The PS cooling fan is likely stuck...
Time to replace it...
There is a wiring retrofit to split the two.....was done by many dealers for free....to bring the PS fan/radiator fan wiring harness up to the 2005+ build standard. Sometimes the wiring instructions are included with new fans....they should be around in PDF form too...

 

Negative, Ghostrider. The fan works fine, I stuck 12v to it while it was on the bench and it spins quietly and freely. I believe I blew it when I got that spark while disconnecting the wires, I should have disconnected the battery first. Plus, the 5A fuse is for the relay, a stuck fan wouldn't blow the fuse.

 

I did just LOL sir... and I will make sure to remind my students that even one time a guy who worked on Space Shuttles forget to check fuses first!

Well, that could be it. Fuse F05 (5A) runs the coils in the relay that power the fan....

 

If the fan is good...fine..thought you powered up the rad fan....not the Power steering cooling fan..
The perverse thing about the wiring is the relay power powers the PS cooling fan (from BEFORE THE RELAY)....( it is a 2nd small fan that look like a small computer cooling fan).....thus the issue....water gets in the bearings...or road debris..and it blows the fuse...disabling the relay....thus disabling the rad fan..... Good to hear it is all working for you!!
Up here in new England, we can destroy a PS fan every 30,000 miles or so....the OEM duct from the cabrio's can shield it a bit, preventing the issue.

 

Ok, I see that on the diagram... I was wondering what the second small fan was for... (I never saw an R50/53 system up close)..

 

I'll keep that in mind; if it blows again, I'll know what to check.

 

OK, I found my problem. When I installed the new kit, I decided that since I had it apart to go ahead and install a new relay since I've hear tales of people whacking the assembly with a screwdriver to make it work; seems that over time some of them get sticking. Preventive maintenance is good, right? Long story short, the 5 pin relay I picked up at O'Reilly's isn't wired like the OEM relay, even though it's got the same layout. It plugs in just the same, but the numbers are just going to different pins than the ones on the OEM. Don't ask me how long it took me to figure that out. Got it wired up to the proper pins on the new relay using crimp connectors, put it together and stuck the whole thing back on the car, and it's working like a charm.

Next step is to try to find out what is up with the readout on the tach; when I got finished installing the fan the first time, the readout came on and started working, then went out again, and I haven't seen it do anything since.