AC Help

[GGawaran]

Got everything back together and now it's stuck in RECIRC as opposed to fresh, so next thing to check when im tearing the center console down is to check the CCU and continuity in the harness, at this point I would take the CCU over the harness, seems like less of a PITA to fix haha.

That being said though, @Old Guy what version of deoxit do you use? I change the relay and it's still getting a bit hot, so I believe the contacts may have some corrosion on it causing some additional resistance and in turn heat on the relays..

 

[Old Guy]

Got everything back together and now it's stuck in RECIRC as opposed to fresh, so next thing to check when im tearing the center console down is to check the CCU and continuity in the harness, at this point I would take the CCU over the harness, seems like less of a PITA to fix haha.

That being said though, @Old Guy what version of deoxit do you use? I change the relay and it's still getting a bit hot, so I believe the contacts may have some corrosion on it causing some additional resistance and in turn heat on the relays..

I am a little confused. Did you do the test described on page 22-89 and confirm that the recirc motor is moving from recirc to fresh and that the contacts on the motor are changing status? If all the stuff at the motor end worked, if you do the operation check described on page 22-13 can you hear the recirc flap moving between steps 1-2 and 5-6 (the lights on the display should also change status)? Previously, you said the system passed the operation check. If the stuff at the motor works and you now fail the operation check I am thinking a likely candidate might be that the connector at the motor might not be completely seated. If the operation check works that suggests that the wiring and motor are OK and the problem may be that the control buttons allowing you to select between recirc and fresh may have failed. I have replaced the capacitors in my CCU; but, did not fiddle with the faceplate so I don't know whether the switch contacts are accessible and repairable.

I use the D100L in the 25 ml bottle. A little bit expensive and 25 ml goes a long long way. You can get it in smaller quantities. The D100L and the Ox Gard work well with surface oxides on the contacts / terminals; but, if the terminals have significant surface damage such as pitting or corrosion they need to be replaced or at least cleaned to get some bright metal and then apply the D100L or Ox Gard. That relay should be at the same temperature as all the other relays in the relay box. More importantly, did a new relay improve the air flow by increasing the voltage to the blower motor?

 

[Honcho]

I have a potentially simpler answer. It may have to do with re-foaming the air circulation door. I noticed when I re-installed the door with new foam, that it was fairly compressed on the inlet screen in the closed (recirc) position. The door could be hanging up on the foam and not opening completely to the "fresh" position. I suspect this is what's happening with my door as well and plan to use a scope to inspect the operation. It may be why my "fresh" air blows so weakly.

 

[GGawaran]

I have a potentially simpler answer. It may have to do with re-foaming the air circulation door. I noticed when I re-installed the door with new foam, that it was fairly compressed on the inlet screen in the closed (recirc) position. The door could be hanging up on the foam and not opening completely to the "fresh" position. I suspect this is what's happening with my door as well and plan to use a scope to inspect the operation. It may be why my "fresh" air blows so weakly.

I tested this with while the blower was out of the vehicle using the power probe I bought, no binding at all (thankfully) with the 3/16ths foam we used for the recirc door.

After determining that it was not binding I opted to leave it in the recirc position instead of fresh air to compare airflow and coolness of the air coming out. As I thought the CCU unit was not doing anything when trying to switch from recirc / fresh options.

Without testing the continuity of the wires or doing a visual on the CCU board I am left with those two things left to test, which I will test when I go in to do some radio work.

 

[GGawaran]

I am a little confused. Did you do the test described on page 22-89 and confirm that the recirc motor is moving from recirc to fresh and that the contacts on the motor are changing status? If all the stuff at the motor end worked, if you do the operation check described on page 23-13 can you hear the recirc flap moving between steps 1-2 and 5-6 (the lights on the display should also change status)? Previously, you said the system passed the operation check. If the stuff at the motor works and you now fail the operation check I am thinking a likely candidate might be that the connector at the motor might not be completely seated. If the operation check works that suggests that the wiring and motor are OK and the problem may be that the control buttons allowing you to select between recirc and fresh may have failed. I have replaced the capacitors in my CCU; but, did not fiddle with the faceplate so I don't know whether the switch contacts are accessible and repairable.

Yeah, so I tested the motor directly, and through the short wiring harness. Was able to confirm continuity and power the motor both ways.

And yes in regards to the operation check assuming I did it correctly the CCU did not throw any codes which is why I thought it might have been the recirc motor going bad.

 

[GGawaran]

I use the D100L in the 25 ml bottle. A little bit expensive and 25 ml goes a long long way. You can get it in smaller quantities. The D100L and the Ox Gard work well with surface oxides on the contacts / terminals; but, if the terminals have significant surface damage such as pitting or corrosion they need to be replaced or at least cleaned to get some bright metal and then apply the D100L or Ox Gard. That relay should be at the same temperature as all the other relays in the relay box. More importantly, did a new relay improve the air flow by increasing the voltage to the blower motor?

The increase in air flow was more than likely due to the flap now being stuck in recirc vs fresh air mode. To say if it helped or not I couldn't say as I had the blower out already when I was able to pick up a new relay.

In regards to the D100L and cleaning up the contacts, do you have any recommendations on how to do so? I was just doing to run a little bit of D100L and insert and remove the relay a couple of times if I am being honest haha.

 

[Honcho]

I tested this with while the blower was out of the vehicle using the power probe I bought, no binding at all (thankfully) with the 3/16ths foam we used for the recirc door.

After determining that it was not binding I opted to leave it in the recirc position instead of fresh air to compare airflow and coolness of the air coming out. As I thought the CCU unit was not doing anything when trying to switch from recirc / fresh options.

Without testing the continuity of the wires or doing a visual on the CCU board I am left with those two things left to test, which I will test when I go in to do some radio work.

Historical odds say it's your CCU.

 

[GGawaran]

Historical odds say it's your CCU.

Yeah I hope so, per the previous owner he said the CCU was repaired very recently, less than a year or so?

 

[Old Guy]

In regards to the D100L and cleaning up the contacts, do you have any recommendations on how to do so? I was just doing to run a little bit of D100L and insert and remove the relay a couple of times if I am being honest haha.

Jonard makes these really thin files that you can insert into the terminals to clean them.

https://jonard.com/sites/default/files/product_files/Data%20Sheet%20-%20Relay%20Contact%20Burnishers%20-%20OB-1%2C2%2C3%2C4.pdf

The narrowest is 3/16" which may or may not be narrow enough to fit into the socket terminals. Digikey sells them. Scrounge around on the internet and you may be able to find something cheaper.

Or you can just dribble the D100L down in there and see what happens.

 

[Old Guy]

Yeah, so I tested the motor directly, and through the short wiring harness. Was able to confirm continuity and power the motor both ways.

And yes in regards to the operation check assuming I did it correctly the CCU did not throw any codes which is why I thought it might have been the recirc motor going bad.

So I am probably not being clear.

You said you originally did the operation check on page 22-13 and everything worked fine. After removing the blower motor, replacing the recirc servo motor and putting everything back together, did you repeat the operation check described on page 22-13? The operation check steps itself through the test and switches from fresh to recirc between steps 1-2 and then back between steps 5-6. The lights on the display should also change status when this occurs. If the operation check says everything works correctly then the recirc servo and the switches are probably just fine and the wiring from the CCU to the servo motor is probably just fine.

Your problem may be the CCU; but, it is not the capacitors on the CCU which is the repair that everybody talks about. If you cannot manually select fresh versus recirc then the problem may be the controls on the faceplate and I don't know whether anybody repairs the faceplate. If the problem is the faceplate controls you would have to contact Brian K or @Heineken to determine whether they can repair the faceplate. If not, then there is no point in sending the CCU out for repair. Just purchase a complete new CCU or live with the inability to select recirc versus fresh.

If the system initially passed the operation check; but, it now fails the operation check that suggests the problem was caused by something you did. The fact that the CCU is able to execute the operation check; but, the display does not change status in one of the steps as shown in the service manual suggests that the CCU might be fine. The step in the test at which it fails the operation check may give you a clue as to what is going on. If it fails at step 1-2 or step 5-6 that could be caused by the flap mechanism jamming and preventing the switch contacts on the flap motor from changing status.

 

[GGawaran]

So I am probably not being clear.

You said you originally did the operation check on page 22-13 and everything worked fine. After removing the blower motor, replacing the recirc servo motor and putting everything back together, did you repeat the operation check described on page 22-13? The operation check steps itself through the test and switches from fresh to recirc between steps 1-2 and then back between steps 5-6. The lights on the display should also change status when this occurs. If the operation check says everything works correctly then the recirc servo and the switches are probably just fine and the wiring from the CCU to the servo motor is probably just fine.

I haven't repeated it yet. But will do so once I get some D100L and see if that helps with the heat being generated by the blower relays.

I typically am not very good on the electronic side of things but this issue has taught me a lot of things so it's a win win. Hopefully now I can just source the cause of the flap not moving.

And when I initially did the test it seemed like everything was working but what I was hearing wasn't the recirc flap moving but the airflow motor moving to defrost. I think I mistaken that for the "thump" you said I should be hearing when the recirc motor moves.

Seems like everything is working except recirc/fresh buttons.

By the way I just want to say @Honcho and @Old Guy thanks for taking the time to respond to these, it has been a tremendous amount of help to know where to look as far as the service manual is concerned or a general direction

 

[GGawaran]

@Honcho

Here are the pictures of it when I took it out and disassembled it






And one of it complete