Hi, new to forum and long time ridgeline/ crv owners forum.
https://www.ridgelineownersclub.com/...please.236505/
lots of help here isee so thought i would cross post for more 👀..
thanks in advance…

Long story so summary best i can…

• ac is on, compressor and fans..been this way for many months.
• took to dealer to pay for computer diagnosis as I don’t have honda computer and willing to pay. They said bad switch on high pressure line and bad compressor. I said bs as the switch willl only stop the ac..they claimed when off it stops. I tried it did not..AND i replaced the switch with chinesium oreillys as honda is out of production on it. No change. Theywanted 2 grand to replace compresor and switch. Iwas upset as theywere notthe issue and proved it.
• also inpected wires on body control module..and inspected
• back to dealer for months..they try everything hondatech ..replacement gauge module..nothing..then say has to be switch..i said no and i replaced..they said honda part needed and not in stock..ok ill wait took truck back and fixed head gasket..so waiting game on part..its not the issue but…
• relays swapped replaced, control panel hvac removed always ac on..not just compressor, fans everything. Something is telling it to run.
• bought blue driver scan tool..kinda cool. Founddealer did not wire sunroof anddimmer switch wire pinched behind speedometer!!! Shameful …..All fixed but getting 2 relay codes??? Related to ac?? Issue? Noissues lightsand wipers fyi now wires routed
• fuse pulled on comp relay for now fans still run. All else fine..225000 miles

thank you

 

What happens if you unplug the connector to the A/C pressure switch? Does both A/C compressor and fans still run?

If they still run with A/C pressure switch unplugged, then the issue may be related to the PCM, or wiring from/to PCM.

 

Great question..
originally when they said i needed compressor and swith for 2 grand as clutch debris was obvious.. they said it was an aftermarket compressor, which is bs because i replaced it with denso made in japan. I now realize why i got cold air justdrifting through vents with hvac off..the compressor running all the time and wearing it out. I was very upset because for 2 grand it would have wore out again..
they said second time it was switch…i said no way..they said when they remove it it stops… so i get it back replace the switch myself and same issue but then realize even unplugged it runs…fans everything.
i did notice though that at initial start up the fans and compressor do not run for about 3 seconds so i assume that is for start up procedure normal and in fact can be controlled..
i told dealer it runs unplugged! And they may have been fooled.
fast forward at dealer for 2 months! And i know for fact itwas worked on and off as i seen it in and around shop..computers opened , honda tech line, replaced gauge control module.. then i say whats the deal and they say it has to be switch and honda has no part, on back order ( i can confirm this).
i said i replaced oreillys chinesium and they said it has to be the switch and need honda part to verify..so i took it back to fix misfire and head gasket ( note ngk has bad coils out there)…
my frustration is it cannot be switches? They only run high fan and prevent ac from running?
i will unhook switch and see if fans go off as comp fuse unplugged again but i and they are completely baffled other than they say switch.
temp is 27f not sure if that will factor but will try..

thank you for advice

 

Confirming..28f dead cold start both fans running continuously with 3 way switch unplugged.

 

thanks
any thoughts as to look next step assuming pcm ok? A grounded wire to the pcm? I am not that good following wiring or obvious wire to check and how, or what communications wire does. Dash shows ac light going out and disconnecting still runs trigger short before pcm and after?
thoughts?

 

With the connector to the A/C pressure switch unplugged, there should be no A/C ON input to the PCM and the PCM should not be grounding and energizing the relay coils.

Normally, when the A/C is on:

1. The climate control unit (RTS, RTL, EX-L) grounds the A/C ON input of the PCM through the A/C pressure switch. (In more detail: The relay control module detects that the A/C is ON when the climate control unit (RTS, TL, EX-L) grounds the
reference voltage sent through the A/C pressure switch. The relay control module communicates this information to the PCM through the B-CAN and F-CAN networks of the multiplex system.

2. The PCM then separately grounds the A/C compressor clutch relay coil and the A/C condenser fan relay coil. Power is then supplied through the relays (after the relay coils are energized).


There may be a short somewhere along the circuit (e.g., Relay Control Module -> MICU -> Gauge Control Module -> PCM) causing the PCM to ground the relay coils.

 

Wow..thank you..i need to study..
So potentially a short to ground alongthose wires..
i shall identify each assume starting by unhooking from pcm somewhere and looking for short to ground?
Edit..looking for power short to pcm..not ground..the pcm grounds the relays..
again thanks
also these 2 codes come up although noissues with each..anything related?

 

Because the turning the AC on and off at the climate control panel also has no effect I would guess the issue is between PCM and Relay. Like the control side of the relay is shorted to ground. But that doesn't really make sense because then the control side for both fan relays AND AC clutch relays would also need to be shorted to ground. The AC would also not wait 3 seconds after start up if shorted to ground. It would just be on with key on.

Don't think it is a short between the climate control unit to gauge cluster to PCM. That is all CAN bus and would have CAN errors stored in just about every module. The dash would be lit up like crazy.

The pressure switch is directly wired to an input on the PCM, unplugging it should have made the AC stop if the PCM was working correctly.

I think your PCM has lost it's mind.

 

i know nuts right? Thats whyi took to honda..
here is that delay at start, so its like something is not shorted?

 

Yeah shorted is probably not the case.

If you had a scan tool like an HDS or clone you could see the AC request input, the pressure switch input, and the ac and fan relay control output on the PCM.

Then you could see if the AC being on is actually as requested for some reason or if the PCM thinks everything is happy and is oblivious to what is going on.

 

maybe i need a new dealer

 

Honda dealership has the tool. Wether or not their techs know how to or are willing to use the tool is another topic.

 

I ran 2 wires through clutch 7.5 amp fuse and ran 2 wires to a switch in the cab to turn on when needed in heat. Seems to work and used inline hot side fuse 7.5amp to switch.

 

Not sure related but slow coolant temp code i thought was because fans always on from AC , was not
slow coolant temp rise po128 was in fact thermostat. I had SMOD a few years back and saved it .but i went through 3 radiator caps as the transmission fluid tears up the rubber..bet that rubber here was gone too. 180f now..

 

Thanks to all who helped!
Fixedfixed fixed!!!!!
relay control module..it even fixed the wiper and headlight switch module code showing up!!!
so maybe that was a hint too !!! It said module..
wow…i bet that damn thing is responsible for a lot of mysteries…
ebay 58 bucks used had to transfer seat heater relay.

i will cut the damn thing open and see wth? Why would they have those not accessible..
@tech8 you were close!!!!

 

Cause of death?
unknown… there is a lot in there..
pretty sure it fixed myalarmgoing off..i can lock truck now has notgone off.

 

Hi
OK , returned part to dealer told them do not order pressure switch.. thought i would peak curiosity to learn and fix after all the work.. grew tired. Settled for refund of my diagnostic fee from August 2022.. $142.70.. i wanted at cost for new relay box.. they said no date to get it..and there cost $380... not happy with not caring after all that work and dropping off old part for Honda.. pretty sure they don't care [img]data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7[/img]

oh well.. I'm done for now and hoping case closed..
so far all working perfect.. and no alarms going off.. FYI the hood latch that was disconnected was from attempting to fix alarm years ago on forum advice.. and also horn i thought was alarm only..
thanks all