AC cutting out when fan switch is on? repair info

[ahardb0dy]

On my 94 pathfinder when I had the AC on and moved the fan switch to setting 3 or 4 the AC would sometimes shut off, I could tell when the light in the AC switch would go out, I used to have to wedge a piece of plastic under the lever to get the AC to stay on. Today finally tackled the problem. First took the plastic surround off of the center console ( the part that surrounds the radio and HVAC controls),next removed the AC switch and the knobs on the HVAC levers, next removed the trim on the front of the HVAC controls, removed the 3 screws that hold the controls in, had to figure out how to remove the cables from the levers and discovered the rear of the levers are held in with 2 clips, spread the clips apart and pry up on the lever carefully with a flat screw driver, lift the lever off of it's pivot point, you can than twist the lever to unhook it from the cable. There are 2 cables on top and one on the bottom, after each lever is separated from each cable there is a small "C" clip that holds each cable sheath into it's plastic mount, just pull the clip out using a pair of needle nose pliers, once the clip is removed the cable can be pulled out of it's mount, be careful not to bend the cable or the metal part that is inside the sheath of the cable. Next pull the HVAC control forward and unplug the 2 connectors, one is a 6 terminal black plug and the other is a 2 terminal white plug (for the light), the HVAC control will still not come completely out as there is a metal wire clip on the bottom left that has to be removed, I removed the screw from where it mounts on the duct behind the HVAC controls but later found out you can spread the parallel wire apart to remove the HVAC controls. Once the control is disconnected take it somewhere where you can work on it on a table or something. Turn the control up side down and you will find 2 screws that hold the actual switch part together, remove the 2 screws, the cardboard cover that protects the wire terminals and set aside, remove the top of the plastic switch assembly and turn it over. You will see this:

 

 

this pic was taken after I cleaned the contacts, did not take a before pic but just picture the copper dirty, lol

 

I did not have metal polish so I used some Mothers pre cleaner on a polishing wheel on my dremel to clean and buff all the copper surfaces, after the copper contacts were clean I used some TV tuner spray cleaner to remove any residue of the Mothers pre-cleaner, than I pried up on the copper contact and removed this part:

 

 

there is a spring under this contact as indicated in the above pic, clean the 3 tabs that help to locate the copper contact and stretch the spring slightly, re-install the copper contact you just removed making sure it can move freely up and down.

 

the contact that controls turning the AC switch on and off can be seen here:

 

 

(click on the pic to make reading the note easier)

 

remove the small contact using needle nose pliers, there is a spring on the bottom, slightly stretch the spring than re-install the contact,

 

re-assemble the switch, You could probably use some dielectric grease on the contacts but I did not,make sure to re-install the cardboard on top of the switch assembly before putting the screws back in

 

take the switch assembly back out to the truck and plug the black plug back in and test it, it should now work perfectly, re-assemble in reverse order,

 

NOTE: the 2 cables on top criss cross each other, meaning the cable coming from the pass; side goes to the lever on the left and the cable coming from the drivers side goes to the lever on the right. The cables can be a pain to get back in their holders, I used a needle nose pliers grabbing the cable sheath to pull it slightly and move it into position, once the cable sheath is in it's mount, hold it as far in as it will go, place the "C" clip back in it's groove and push it down using a flat screw driver or similar tool, once the sheath is secured you can re-connect the lever.

 

 

I didn't intend this as a how to when I decided to post that I got my AC switch to work but figured I would write what I did to get it to work.

 

Thanks

Edited August 16, 2010 by ahardb0dy

[JamesRich]

Cool thanks man! I need to do this too. I don't have to wedge anything under the lever to make it stay on but sometimes I have to wiggle it to get it to stay on. Thanks for exploring this for us, because I'm lazy and would have just kept wiggling it.

James

[ahardb0dy]

I was putting it off because I knew it was going to be a pain in the rear to do but, decided Sunday night that I was going to do it Monday so I did. Worked fine today!!

[Alkorahil]

Having done this project before, I too can vouch that it is not 'fun'.

[ahardb0dy]

hardest part was getting the cables back in, rest was ok, after replacing the knock sensors (2) on the Infiniti Q45 we used to own (Major FUN JOB !!!) and removing the whole dash from my 90 sentra I'm not afraid to try to do anything:

 

 

 

[JamesRich]

hardest part was getting the cables back in, rest was ok, after replacing the knock sensors (2) on the Infiniti Q45 we used to own (Major FUN JOB !!!) and removing the whole dash from my 90 sentra I'm not afraid to try to do anything:

 

 

 

 

If your that good at it take a little road trip and come visit south central louisiana, and I'll let you fix mine! I'll buy you some beer and boudin!

James

Edited August 20, 2010 by JamesRich

[ahardb0dy]

thanks don't drink beer, will take pizza

[JamesRich]

thanks don't drink beer, will take pizza

Don't drink beer? Around here even 10 year olds drink beer with there pizza!

 

Root beer that is.

James

[ahardb0dy]

Don't drink at all, what do you need to fix? We can rebuild/repair it, "My old man is a television repairman, he's got this ultimate set of tools. I can fix it. !"

[Meandmy92Pathy]

Don't drink beer? Around here even 10 year olds drink beer with there pizza!

 

Root beer that is.

James

 

James, notice that he didn't mention the boudin.....hmmmmmm, what's that????? Now that I live in the great northwest of the Bayou State, I don't get the good stuff anymore!!!!

[JamesRich]

James, notice that he didn't mention the boudin.....hmmmmmm, what's that????? Now that I live in the great northwest of the Bayou State, I don't get the good stuff anymore!!!!

Yea you can only get good boudin in south central La. I've tried some from all over the state and the best so far is from two places a few miles from my home. "The Best Stop" and "Don's Specialty Meats" both in Scott, La. The Best stop ships it frozen all over the US, and there are always people from out of state there picking some up. They have a small parking lot but drivers stuff 18 wheelers in there when they are passing through just to get some boudin.

 

On the A/C switch, I picked one up in the pick a part the other day. When I get a chance I will take it apart and clean it so that when mine gets too bad I can just swap it out. I grabbed the whole dash out of this 90 model truck too. It's perfect with no cracks but it's brown. I picked up some Burgundy vinyl paint to try on it.

Has anyone used vinyl paint before on a dash?

James