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Posted on November 18, 2015 by BAT Team

P0645 – Air conditioning (AC)

BAT Team

By BAT Team (Contact Me)
Last Updated 2015-11-18
A site with free advice from mechanics.

Trouble CodeFault LocationProbable Cause
P0645 Air conditioning (AC) Wiring, AC system

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Jeremy NoeJason WellsBenjamin JerewPierre Recent comment authors
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Pierre
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Pierre

Liguei meu Ar Condicionado direto sem o módulo ( Fiesta 2009/2010 ), pois o relé estava mandando pouca corrente negativa e não gelava, passei 2 dias tudo ok, o Ar ótimo, agora parou de novo de gelar e apareceu o cód P0645, possível causa fiação. Oque fazer? Grato desde já.
Meu e-mail pra respostas.
[email protected]

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1 year ago
Jason Wells
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Jason Wells

Do I have a relay for the AC clutch and the front and in the back trunk fuse box if so what number please

Make:
Chrysler
Model:
300lx
Year:
2008
Miles:
140000
Engine:
2.7 v6
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7 months ago
Benjamin Jerew
Editor
Benjamin Jerew

The AC clutch relay should be under the hood in the Integrated Power Module, AKA “Fuse Box,” right next to the horn relay. I read the Horn Relay and AC Clutch Relay are fed by the same fuse, so if the fuse blows, you lose Horn and AC. Also, the horn relay and AC relay are identical, so you should be able to swap-tronic them.

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7 months ago
Jason Wells
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Jason Wells

I change all of them .. Still same.. If it hook meter up to plug that goes in to the ac clutch i get 10.7v dc and when i hit ac button in car it goes to 11.5.v Dc If in unplug it from ac clutch and i wire my own 12.v dc it comes on and cold and i check freon presser when ac clutch is engaged and it read normal on ac presser Freon.. Iam confused .. Is 11.5v not enough to kick it on. Please help.. Lol

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7 months ago
Benjamin Jerew
Editor
Benjamin Jerew

This might be getting too complicated to diagnose over the internet, but I’m wondering if you might have a bad ground after the AC clutch. If you’re getting 11.5 V, it seems like 2 V are getting sucked up somewhere else. Double-check you have ≈13.5 V engine running AC clutch disconnected AC engaged, then check ground straps and other ground points for excessive resistance.

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7 months ago
Jason Wells
Guest
Jason Wells

Took it to have it service.. they ran scan on it come to find out it is the pcm.. I ran a switch to the ac clutch so I manually turn it on until my com comes in.. thanks for your comments

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6 months ago
Jeremy Noe
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Jeremy Noe

Has anybody found the wiring issue to the a/c compressor

Make:
Ford
Model:
F250
Year:
2005
Miles:
298000
Engine:
6.0 diesel
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1 month ago

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