WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 On 5/30/2019 at 12:23 AM, Madkaw said: So here are the harness ends of the wiring. I actually just hacked out the harness on the parts truck in the HVAC area . You can see the plugs relating to what I was talking about on the last post. Now these connectors on my truck I don’t think they hooked to anything previously, but they do look like they are supposed to plug into the evaporator box . The white wire is just a loop wire ? Is it a fusible link maybe? My setup looks EXACTLY like this. Quote Link to comment
Crashtd420 Posted January 29, 2022 Report Share Posted January 29, 2022 Have you checked voltage before and after the high pressure and low pressure switch? Maybe one of those is failing..... Quote Link to comment
WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 Yes, both High and low pressure switch are each read 12v with the system on. On the other hand The lead wire to the compressor still reads 7v with the both switches on. Quote Link to comment
WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 Also to reiterate, I know for a fact that there is no break in the line because I not only traced the wires back physically but I also checked for continuity from end to end and all is good. Quote Link to comment
Crashtd420 Posted January 29, 2022 Report Share Posted January 29, 2022 Doesn't make sense, which is what you have probably said a few times... If you say you have 12v in and out of the pressure switches there has to be something between the pressure switches and the compressor that is failing. I have a simpler aftermarket system but the wiring goes from the switch inside, through the pressure switch and then to the compressor.... Quote Link to comment
Crashtd420 Posted January 29, 2022 Report Share Posted January 29, 2022 Check the red wire at the ac relay... That should output 12v... Only thing I see after is a thermal resistor..... find that and check power before and after... Quote Link to comment
WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 Crashtd420@ Thanks for helping so far. I followed this same diagram on my FSM and all three locations where the red wire is, from the relay plug to the compressor lead and to the FICD wire which all share the same line, all read 7v. I’m thinking with the AC relay connected this would then give me the 12v I need for the compressor. I just need someone to confirm that. Until then I’ll just have to wait in a few days when I finally hook it up. Quote Link to comment
Crashtd420 Posted January 29, 2022 Report Share Posted January 29, 2022 1 minute ago, WestPac720 said: Crashtd420@ Thanks for helping so far. I followed this same diagram on my FSM and all three locations where the red wire is, from the relay plug to the compressor lead and to the FICD wire which all share the same line, all read 7v. I’m thinking with the AC relay connected this would then give me the 12v I need for the compressor. I just need someone to confirm that. Until then I’ll just have to wait in a few days when I finally hook it up. Sounds like the relay to me... Do you have 12v on that L color wire? Quote Link to comment
WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 7 minutes ago, Crashtd420 said: Sounds like the relay to me... Do you have 12v on that L color wire? The bigger gauge blue wire, Yes I do sir. Quote Link to comment
Crashtd420 Posted January 29, 2022 Report Share Posted January 29, 2022 41 minutes ago, WestPac720 said: The bigger gauge blue wire, Yes I do sir. So if you have 12v going in but only 7v coming out... R/L should be power from the pressure switches which you said you have 12v... R/G seems like the negative signal from the dash switch to activate the relay, make sure that works too... If those all check out which it seems like they do, then it is the relay.. Quote Link to comment
WestPac720 Posted January 29, 2022 Report Share Posted January 29, 2022 13 minutes ago, Crashtd420 said: So if you have 12v going in but only 7v coming out... R/L should be power from the pressure switches which you said you have 12v... R/G seems like the negative signal from the dash switch to activate the relay, make sure that works too... If those all check out which it seems like they do, then it is the relay.. Got it. I’ll chk that in the a.m. Txs! 1 Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 I Put a Brandnew oem ac relay in but I’m still getting low voltage (7.55v) at the AC compressor lead wire (red). Any idea what may be causing the low voltage reading? Also I have the dash and the dash harness all taken out so I have better access to the AC components and wiring. Is it possible that the dash harness share a ground that is keeping or preventing the AC compressor power line from not getting the full 12v as it should? Any help would be greatly appreciated! Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 Does the dash harness have any relation to the AC wiring diagram configuration other than the AC dash illumination light that is controlled by the steering column switch? Quote Link to comment
Madkaw Posted February 4, 2022 Author Report Share Posted February 4, 2022 Doesn’t the compressor have some kind of ground ? I’ll look at mine when I get home but I thought I remember a wire grounding the compressor . How are you measuring the voltage at the compressor ? Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 With the compressor Unhooked from the lead wire (red), I’m just measuring that lead wire which I’m only getting 7.5v. Quote Link to comment
Crashtd420 Posted February 4, 2022 Report Share Posted February 4, 2022 1 minute ago, WestPac720 said: With the compressor Unhooked from the lead wire (red), I’m just measuring that lead wire which I’m only getting 7.5v. Can you check it at the relay too? Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 On 1/30/2022 at 12:37 AM, WestPac720 said: My setup looks EXACTLY like this. How do you setup the connection for the relay and the thermo switch. Would you happen to have any photos of that. As mentioned previously, my initially set looks exactly like the last photo on this post. Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 1 minute ago, Crashtd420 said: Can you check it at the relay too? I’m also getting the same voltage (7v) at the red wire to the AC relay to include the FICD solenoid which share the same line. The blue wire at the relay however is reading 12v as it should. Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 I’ve tried jumping the blue wire and the red together and the lead to the compressor gives me the 12v which only indicates to me that there is no break in the line. I’ve also tested continuity on the red wire from the relay to the compressor and FICD just to be sure. All three points appear to be intact. Quote Link to comment
Crashtd420 Posted February 4, 2022 Report Share Posted February 4, 2022 Can you tell if the relay is activating or not? You should hear it click on and off.. It honestly makes no sense.... 12volt in should give you 12v out if its activated.... Quote Link to comment
Crashtd420 Posted February 4, 2022 Report Share Posted February 4, 2022 I am assuming you get the 7v if you turn on the ac? Do you see any voltage if the relay is technically off? Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 I tested the new OEM relay which appears to be working. Correct, I do not get voltage when the AC is not activated. With the AC relay installed I do not hear the clicking sound that it should be making. I’ll have to double chk on that again. Quote Link to comment
WestPac720 Posted February 4, 2022 Report Share Posted February 4, 2022 Just now, WestPac720 said: Here is the AC relay I bought Quote Link to comment
Crashtd420 Posted February 4, 2022 Report Share Posted February 4, 2022 Just now, WestPac720 said: I tested the new OEM relay which appears to be working. Correct, I do not get voltage when the AC is not activated. With the AC relay installed I do not hear the clicking sound that it should be making. I’ll have to double chk on that again. Did you ever test the other two wires going to the relay ? On 1/29/2022 at 11:15 AM, Crashtd420 said: So if you have 12v going in but only 7v coming out... R/L should be power from the pressure switches which you said you have 12v... R/G seems like the negative signal from the dash switch to activate the relay, make sure that works too... If those all check out which it seems like they do, then it is the relay.. Quote Link to comment
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