Is there a way to pull the logicon without having to cut the wring harness? I gave up trying to figure it out last time and just cut the wires...but I don't want to do that with this next parts car...

 

I am looking at my Haynes manual and there are two connectors that hook into the logicon. They can be disconnected easily. I think you are referring to the longer one that snakes up into the dash. I guess you have to small hands or something, because you have to reach into the dash opening and there is another connector near the left defroster duct, right below the windshield. Hope this helps.

 

Three plugs for a logicon.

Two on the back of the logicon, one above the gas pedal and air mix motor.

To get to the third plug, either:
pop off the top front of the dash and reach down
or
take out the gauges, and reach behind them to the plug.
or
reach up from underneith (but you must have tinie, tiny hands to do this)

 

Taking off the gauge cluster and reaching behind has been the easiest and fastest for me. You can see the plug when the gauges are out. The plastic vents behind the cluster will kind of get in the way but theyre flexible enough for your hand to squeeze in there and unplug the thing. Theres also a zip tie holding the logicon's wiring harness to some other crap that gets in the way. If you forget about the zip tie, youre going to start punching anything and everything that gets in your way because by that time, you'll be frustrated and will be reaching for wire cutters.

 

I started to desolder the connector on the board until I read a earlier thread that said it *was* possible without completely destruction of the dash components... But... I decided to continue the desolder process. The only part that sucked was resoldering inside of the cabin... too damn small to get precision welds to the board

 

yes...reaching through the dash was easiest...that ****** was a pain in the *** to reach...next time, I'm just ognna pull the ******* dash...

 

I just did this. After going through all the hassle of removing the instrument panel and a bunch of ducting, I found a reference guide that indicates removal of the dash top (Panel including VIN plate and defrost grills) to access the wiring harness connector that is up near the very top of the dash. Remove the square plastic cover between the grills to access the upper bolt. Remove the bolt. Gently pry the top upward to release the six spring clips on the underside of the top. Work the top backward slightly to clear the front edge and then walk one side clear of the windshield pillar. Once the top is out, the wiring connector is right there. It's really easy to reach. You can also clearly see the air mix and mode motors for testing.
I wish I'd known about this method before I started and hope that posting this will save someone else a big PITA.

 

Thats the method in the FSM, but it usually results in the destruction of all removed plastic parts, due to them being brittle with age. You must've gotten lucky.

 

"ScrapFC" must have the golden touch to handle brittle plastic.

Every time I have to pull trim I have to allow an extra hour to repair broken plastic.

It's a good thing this car is fun to drive..

 

I must be blind. I didn't see anything like that in the FSM. "Magic touch", huh? Nah, it's just that the plastic was already broken, so I had no fear. Seriously, though. It looked to me like the only things you'd have to worry about would be the defrost grills(mine were already broken), windshield pillar trim (Previously cracked) and maybe the screw cover (undamaged!). Other than that, everything is (semi) soft vinyl. It flexed just fine without breaking. Ah well. Now I get to put all the OTHER crap back together after I fix my damned logicon.

 

It's not in the S4 one, but it's on page U-21 of the S5 FSM.

Even if you have an S4, get the S5 FSM. It has tonnes more info than the S4 FSM, and most of it applies to both series.

 

Aha! I just got a S5 FSM and it's MUCH more helpful! Thanks for the tip! Too bad it looks like my logicon is toast. (Loose screws rattling inside shorted and burned the mode control circuit) The good news is that the motor seems to be OK...