1998 Dakota 5.2L P0545 P0645
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1998 Dakota 5.2L P0545 P0645
Slowly bringing it back to life. Took it on the highway after changing spark plugs, wires, etc. Came back with P0545 (either Exhaust Gas Temperature Sensor Circuit Low, Bank 1 Sensor 1, or A/C Clutch Relay Circuit-depending on which internet post you believe) and P0645 A/C Clutch Relay Control Circuit (as a pending DTC). Why the two possibilities for P0545?
I've been troubleshooting the A/C for a bit now but am stumped at the moment.
A/C clutch won't kick in. Regardless of dashboard switch position (off, A/C or Max A/C) I detect 12V on two pins of the relay socket. I tried disconnecting the Low-pressure sensor and jumping the two pins at the harness. I cannot get 12V at the two-pin connector going to the compressor nor can I get power to a third leg at the relay.
Prior to that I tried charging the system but the pressures were, of course, wonky, 90PSI on the low side, ambient 30PSI on the high, as the compressor wasn't running. Wasn't thinking that day, musta been the heat. What I think I was thinking? was charge too low, compressor won't kick Anyway....
I would like to see the dealer PDF referenced by the master. Any suggestions would be appreciated, as would wiring diagrams, troubleshooting flow charts, etc.
I've been troubleshooting the A/C for a bit now but am stumped at the moment.
A/C clutch won't kick in. Regardless of dashboard switch position (off, A/C or Max A/C) I detect 12V on two pins of the relay socket. I tried disconnecting the Low-pressure sensor and jumping the two pins at the harness. I cannot get 12V at the two-pin connector going to the compressor nor can I get power to a third leg at the relay.
Prior to that I tried charging the system but the pressures were, of course, wonky, 90PSI on the low side, ambient 30PSI on the high, as the compressor wasn't running. Wasn't thinking that day, musta been the heat. What I think I was thinking? was charge too low, compressor won't kick Anyway....
I would like to see the dealer PDF referenced by the master. Any suggestions would be appreciated, as would wiring diagrams, troubleshooting flow charts, etc.
THE ULTI-MOD
Joined: Jan 2007
Posts: 19,797
Likes: 36
From: Union NJ
you need to make a NEW thread for a different problem, i have done this for you, next time i will simply delete the offending post, you have been warned.
the PDF is available in the FAQ thread stickied at the top of this forum section.
i would look at the a/c relay in the PDC being bad, especially since yous aid you do not get 12v signal to the a/c clutch harness, replace the relay and let us know what is happening after that.
the PDF is available in the FAQ thread stickied at the top of this forum section.
P0545 A/C Clutch Relay Circ
P0645 A/C Clutch Relay Circ Perf
P0645 A/C Clutch Relay Circ Perf
With the A/C system i would start my swapping the relay with a know good one. if that don't get you the voltage you need to the compressor then your gonna have to trace the wire back to the PDC and look for breaks or melts in the wires...
The Pressure on the low side should be between 25-45 PSI with the system running and its 100something on the high side IIRC. Bottom lline is i would not worry about anything till the compressor runs.
The Pressure on the low side should be between 25-45 PSI with the system running and its 100something on the high side IIRC. Bottom lline is i would not worry about anything till the compressor runs.