QuestionRoland:
This is Ron again and thanks for sending that information. I haven't tried it yet but hopefully it works.
I have another question and this concerns my 1993 Shadow and the non-functioning cooling fan.
Here is what I have done so far. I have replace the fan itself with one that I know it runs. I have also checked the fuse in the fuse box panel. I have replaced the relay (fuse) on the driver's side inner fender. I have also checked the plug in to the a/c. I thought after putting in the different fan it would run, so I tried the defoster and no fan functioning. Any suggestions and thanks.
AnswerHey Ron,
I spent a lot of time on my response this morning. I said nothing about the controller. The fact that the relay clicks shows that the controller is o.k.
I said: the fan ground wire is bad, or the light green wire from the relay to the fan has a discontinuity in it, or the relay has bad internal contact points. I reached that conclusion because you said the fan is good, you do have supply voltage to the relay, and that the relay clicks. What else can I say?
Please take out your meter and trace the voltages and check the ground wire.
If you want to ask another question on this subject, please use the follow-up button, don't ask a new question. O.K.?
Roland
"Are you saying my controller is bad?"
Hi Ron,
Rather than start a new "thread" about the same question I am copying below your leatest response/question. Please continue this using the follow-up approach rather than starting a new question. In this way can other readers with the same problem keep track of the resolution.
I infer by the wire color that your have a 4 cyl engine.
The only thing that you apparently have not verified is whether the light green wire at the plug for the fan is getting 12v as measured between it and a ground point after the fan relay has clicked due to a heat condition sensed by the coolant temp sensor to require the fan to come on (e.g. reads less than 700 ohms) or you have removed the plug from the sensor which should also provoke the fan to come on. If you have 12v on the light green wire plug at the fan and the fan does not come on then the black wire at the fan is not properly grounded to the body at a point near the left headlamp. I say this because you have verified the fan motor, you will have shown that you are applying the 12v to fan via its light green wire, so the only other reason it won't run is that the black wire is not grounded properly.
Yes, if the freon is low or out the clutch compressor will not operate. The compressor also will not operate if the fan relay doesn't operate, i.e. there has to be 12v on the light green wire that is the output of the fan relay switch at both the fan motor and at the A/C compressor relay or neither will operate.
So you have to measure the light green wire at two places and verify that it has 12V on it when the engine is hot, or when the A/C is requested, or defrost is requested. And if you have that, then fan ground is bad and the freon is low or gone. If you don't have 12v on the light green wire at those two points when you should have, then if the relay is clicking and it has 12v incoming supply on the dark blue wire coming into the relay, then the points in the relay are not conducting and you need a new relay, or the the light green wire is broken at the fan relay socket (check the light green wire for continuity between the relay socket and both the fan motor and the A/C relay socket).
I think that summarizes "What to do Now".
Good luck,
Roland
Roland
"I wrote to you the other day about my 1993 3.0 Shadow radiator cooling fan that didn't work, not even with the a/c defrost is on. These are the results of the checks you recommended. There is no in line fuse in the compartment. The solid gray and the dark blue wire both checked out at 12 volts all the time from the relay. The coolant temp sensor, when it was unplugged the fan didn't come on. It had less than 700 ohms but the temperature gage didn't read red hot.
You implied something wrong with the controller unless the a/c compressor is also not functioning. The a/c compressor is not functioning on the shadow.(would it function if it had lost it's freon?)
These things I do know. The fan functions (because we used a jumper wire between the relays and I took a relay out of my 92 lebaron that was functioing properly on my lebaron and put it on the shadow.)Yes the relay clicks. Coolant sensor read 0 but like I said the temp gage didn't read high. It's not getting the proper ground, I suspect? Remember the a/c is not functioning and now what's next? Thanks Ron"
Hi Ron,
You are welcome. I have forgotten whether you have the 4 cyl or the V-6 engine, and unfortunately the archives do not show the names of the questioners so I can't identify your earlier question without looking at a couple of dozen such, one at a time.
Now most important is that the radiator fan has to always run when you turn on the A/C (for either simple cooling or for defrost). If your A/C compressor is working when you do that, then that means that the fan relay is closed (should be supplying 12V to the fan motor). If the A/C compressor works and the radiator fan doesn't then the light green wire from the fan relay socket to the fan motor plug is 'open', the fan motor is no good, or the black wire at the fan motor plug that goes to the ground near the left headlamp on the side shield is 'open' or there is a loose ground connection of that wire. So check those if that is the case.
If there is some other time when the fan won't work, i.e. when the engine gets too hot, and you aren't asking for A/C, I believe that the only way to get to the bottom of your problem is with a volt-ohm meter.
Do you have one?
You could figure it out this way. If you have the V-6 there may well be a 20 amp fuse in the engine compartment near a group of wires that are fed from the battery that look like colored spaghetti (single color wires, not striped). The fuse will be in an 'in-line' connector. I am going by the '94 diagrams though because I don't have the '93. The '92 version didn't have the fuse. If you have the 4 cyl engine then you won't find the fuse in any case. But if you find an in-line fuse as I described, check it. The fuse in the fuse box that you checked is likely for the in-cabin blower motor and has nothing to do with the fan motor.
Going on from there, you need to use the meter to check the four wires on the fan relay plug (that is the rear most relay of the three on the left inner fender). There will be one wire that is either solid gray or solid red (4 or 6 cyl) and that should have 12V on it all the time. There should be a dark blue wire that should have 12v on it when the ignition switch is in the "run" position.
If both of those wires are as described, then the only reasons the fan won't run when the engine is hot is that the coolant temp sensor is not working properly (disconnect the plug at the coolant temp sensor and the fan should come on instantly, which checks the circuit, but not the sensor itself. The sensor itself has to read less than about 700 ohms when the temp gauge read hot for the fan to be activated. If it doesn't read that low a resistance then you need to replace the temp sensor) or it it does read that low then the dark blue/pink wire at the relay socket is not being grounded by the engine controller (at its pin 31) which is supposed to interpret the coolant temp signal and do this grounding. That would imply something is wrong with the controller, unless the A/C compressor is also not functioning because it also depends on the same grounding to occur. So you could see if the grounding is occuring by putting your ohmmeter between the dark blue/pink wire and a ground (shiney surface on the engine or the (-) post of the battery and see if it reads 0 ohms; you could also listen or feel for whether the relay clicks). If it doesn't and the temp gauge is way high and the coolant temp sensor is under 700 ohms then the contoller has failed to do its job.
This is a very long essay, so I will stop here and let you consider all the possibilities.
Roland
