Only 6.6 volts at ac compressor

Jneal1974

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Make
Dodge Ram
Model
2500 Quad cab 4x4
Year
2006
Miles
326288
Engine
5.9
I just bought my truck it’s a 2006 2500 5.9 the ac has not worked. I can’t find any bad fuses with my power probe I only have 6.6 volts at the ac connector and I can apply 12 volts to the compressor and it engages. Is there a known issues that would only give the 6.6 volts or do I start tracing the wire and looking for an open? Thanks in advance
 

billr

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Is there a relay for that A/C? If so, swap it with a similar one on the panel.
 

Jneal1974

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I haven’t been able to interpret the fuse panel very well nothing says A/C on the cover for the fuse block on the drivers side under the hood
 

billr

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There may be another panel inside the cabin, but that would seem odd ("Chrysler") to me as the battery and clutch to be powered are both out in the engine compartment. Post a picture of what is shown on the cover of the engine panel?

Are you reading that 6.6V with the other meter lead connected directly to the battery ground terminal?
 

NickD

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Some clutch coils have a two terminal connector, others only had one. The problem with one terminal, the other terminal has connected to the case of the compressor and received its ground through the brackets, and corrosion would drop a substantial voltage. Had to be taken apart and wire brushed, same with alternators getting its ground through the engine bracket.

Wouldn't be a problem if they used aircraft grade aluminum, but oh my God, the would cost an extra 10 cents per pound. On some would drill and tap a hole, using a star washer to add a case ground wire.
 

Jneal1974

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Mine has the 2 wire plug I used my power prob and energized the coil with 12 volts and it engages the power wire come to the compressor only has 6.6 volts I’m thinking I have a corroded wire some where since I don’t see an A/C relay in the fuse box. Was hoping there was another location for a relay
 

billr

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Be patient and hope somebody who knows can chime in about a relay. I would be surprised if there isn't one.
 

NickD

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List your vehicle, 20 bucks for a year's subscription, found these to be far superior than OEM shop manuals, give direct information, not over several thousand pages of repeated safety information.
 
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