danec020

Ok guys, this is one for the pros because I am at a loss. The other day my car's (S4 10thAE) idiot cluster lit up fully multiple times as if a short was going on. Now I know this normally means your alternator isn't working, so ofcourse having the FD Alternator installed I checked to make sure it was working. I checked its output and it always ranged from 13.6-14.5 with full load being high beams, blinkers, wipers, blower, and radio. So I know the alt is good, even then the idiot lights blinked my voltage stayed steady.

So later I noticed my sunroof stopped working, I turned the car off and back on and it worked again... Few minutes later the same thing, well then I learned I could jiggle my keys around in the ignition and that would also make the sunroof work.

So that makes me think it is a ignition problem, because anytime my sunroof doesn't work I can just jiggle the keys a little and it will work... Once it starts working its good to go though, no cut outs....

Now the other weird thing about this issue is when my car started this issue yesterday, I was driving at night and my AC was working flawlessly. So after I got home I removed all my wires from the alternator looking for shorts, and reran them to be sure it wasn't a loose connection somewhere on the ALT... This was all prior to me driving while checking the voltage (I should have done that first instead of wasting my time). Now my AC isnt working... The compressor is kicking on but the AC is not blowing cold. Now my compressor, lines, evaporator, drier, and O-rings are all new less than 1 year old. It is running 134a and it was working great, so good the previous day that the vents were putitng out fog it was so cold...

So my question now is, what the heck is causing my blinking lights, the sunroof to work when i jiggle the keys and my AC to not blow cold even though the compressor is kicking on?

If it is just the ignition switch that is causing the lights and sunroof, then that would mean my freon leaked out, but it appears to be charged. (no bubbles when running, but I havent ran it long enough for my lines to get cold to check. I dont want to burn up a brand new compressor just incase )

Just to note, my car doesn't die or buck or anything when the lights blink on and off.. Sometimes they stay on for 3 seconds, sometimes less. The radio and electronics all work great still and the Voltage meter stays steady.

The FD alternator is wired correctly too Icemark So I believe, I have the wire running the my EGI fuse, not straight to the positive post. So please for the love of god help me with this issue.. I hate small problems like this. It isnt hurting my car any but I want it fixed! As well as my AC back lol.

Dane

danec020

Tomorrow morning I am going to try to pull my CPU and look at the solder points... That’s another possibility I guess... What exactly does the CPU control in the interior? Could it be coincidence that jiggling my keys in the ignition makes the sunroof work? And how about the AC Now? I doubt it is leaking because none of it is old, it’s used daily and never showed signs of getting warmer, but I guess it is possible....

Also, my clock stays set, doesn't effect the time on it so I am pretty sure it isn't the cluster solder points... But I do have the Shift up light in fifth gear and it likes to blink... is that also the CPU?

Icemark if you could confirm any of this, I would appreciate it . I know you have a lot of experience in this area and did a great job on my wiper switch .

Dane

misterstyx69

iTrader: (142)

Check the main wire going to your engine bay fuse block,,sometimes that gets corroded (under the block itself)..the Idiot cluster sounds like it is on it's way out too..and another thing Why would you Run ANYTHING to YOUR EGI Fuse?..that is just asking for something to Screw up down the line,maybe already has. Check battery connections and Ground connections at the Engine and the Alternator..One more thing clean the area Of the Alternator where the BIG BOLT goes through it.That point is Like a ground also..Good Luck.

danec020

Well, I am positive the alternator and its spots are all good. The cars charge is solid, and i monitored it while driving with the shorts blinking. I wired it to the EGI fuse because thats what Icemark suggested if I understood him correctly, if not I don't think it could really hurt anything. The wire I went to the fuse looks for a 12V signal, thats all, so wire it to that fuse gives it the signal it needs when the ignition is on and restricts the amps which should all be ok I think.. Let me know otherwise if not .

I got the AC Compressor back on, it was just the cigar fuse. But the car is still not blowing cold air... The heater works, and the system has to have freon since the pressure switch is allowing the clutch to kick on and the ac was working flawlessly... So my question about that is, logicon or the air mixer (forgot what the unit was called)?

I haven't had time to yank the CPU yet, trying to fix the AC problem first since I need that more than the idiot light problem fixed :P.

Dane

danec020

Welp, I am officially stumped. I will be checking other things today as they come to mind but any help would be appreciated.

I pulled CPU, and Idiot cluster. Their solder points looked great, clean as a whistle. I resoldered them anyway to make sure it wasn't the issue. Problem still there. So if it isn't the Alternator, CPU, or Idiot cluster what else could be fualty besides the ECU? I have a RTEK 2.0 so I am hoping it isnt the ECU, and in the event it is the ECU would it have affected something else? And is there a quick way to test the ECU?

Thanks
Dane

Icemark

Boy you are barking up some wrong trees.

You have a bad ignition switch. You can rule out the Freon level by if the compressor is kicking on. Too little freon and the clutch on the air condition pump won't kick on.

as a hint, wiggling the ignition switch should never make something work or stop working. Fix that first, then trace down if you have any other issues.