FOUND POSSIBLE ISUUE...Added in new reply with a photo
1997 XJ6
I have tested both blowers. They work on their own.
I replaced the Blower Resistor and still no air. I tried a used resistor first. But assumed it must also be bad. Then got a new one.
I checked the power going to the resisitor...when I turn the fan control the voltage changes, so the control panel works. tested all of this before buying a new resisitor.

Check updated reply

 

Sorry to hear the problem has persisted in spite of all of the new parts. My AC blower stopped also, but, the dealer in OKC knew of the issue and guessed correctly. The fan blows cooling air over some component which failed. A "reostat" I believe. He replaced the item, no problem now.

 

That's the "Resistor" I replaced. Have been told it is a common problem, but I guess it wasn't my problem. But I guess it is possible to buy a couple of bad items. Wouldn't be the first time.

 

Is there a way to test the resistor?
Maybe I purchased two bad ones in a row?
All relays and fuses are good.
The ci=ontrol panel is good.
Both fans test good.

 

OK, 2 wires go to the fan...Solid Orange (Ground) and Blue with White Stripe (12 volt)
When I test this plug, while adjusting fan switch at the panel, testing only Blue and grounding to the chassis, it stays 11.98 volts.
If I use the Orange as a ground, the voltage changes with the turning the knob.

Attached a Photo

Ok, so then I plug in another fan from other car, it doesn't work...but does fine straight to battery. So I check the Blue.Wht wire, 12 volts, so I plug it into either the test fan or the fan in the car and it goes dead to 0.00 volts...unplug it, right back to 12 volts....

Now that is the pass. side...the driver side is different. It has a maximum of 0.56 volts on the Blue wire, and does not change, plugged into the fan or not...

Any Ideas?

 

Ron:]
I did not follow all of that BUT, the fact that you have different voltage readings is certainly a result of voltage drop across the resistor. Ohm law says the voltage drop is equal to the current multiplied by the resistance, So, the motor drawing more current has a higher voltage drop in the resistor. Voltage from the battery (12v) minus the voltage drop of the resistor (I*R) equals the voltage at the motor. You read "resistance" (go figure) across the resistor with your DMM to test it. I do not know, but I guess that the resistor for the blower is about 4-10 ohms.

I will look at the circuit later tonight to see where the resistor is actually wired, but from your description, it sounds like it is in the orange wire circuit, No current flowing, no voltage drop, meter reads 12 volts. The resistor probably has a high value, so with current (the fan plugged in), high voltage drop. OR, other resistance in the circuit is causing voltage drop, like connectors or the switch.

My XJS has both a resistor and an electronic voltage controller, for different ranges of speed, so it very well might be the electronic control. As I said, I will look for you tonight.

 

Thanks...where is the voltage controller?

 

Ron:
Understand I am giving you all this from Manuals, not having actually seen any of it on my XJ6. I do not see a power resitor in the XJ6 circuit, only a sense one. We are working on the XJ6, right? The resistor wires to a module that shows as being integral with the motor itself. It has blue, green, and purple wires connected.-

BUT, the blue/white wire should source power any time the AC fan is on- the speed control parts are in the ground side which is the orange wire as you correctly identified. The blue/white wire should source 12 volts to ground without regard to the controller. AND- the controller has a bypass and should allow the motor to run at high speed when demanded . So, I BELIEVE you probably have a bad supply relay or even a bad connection from the fuse panel. Something has a high resistance connection allowing you to read voltage until you add a load. The power supply relay is shown as CA 58, but the bypass relay is shown with the same number, so something in the schematic is screwed up. The relay is shown to be in the right kickboard. There have been reports of water getting in there and causing corrosion on the ECU- I would sure give that a closer look. Of course, switching relays with ones known good - horn? or other? to test is a good test.

Edit= re-reading your post, I believe it is the BL/WT whire that goes to zero volts, right? If not, I will try again!


Good luck.

 

ok...going to go do some more testing...yes, the Blue/White goes from 12 (unplugged) to zero when plugged into the RH fan. the LH fan is 0.5 volts either way

 

So, neither fan runs? And it IS an X-300, right? If neither fan runs and they failed at the same time, I guess you either have a fuse or module issue. I don't have my manuals available, so I do not know the fuse number. BTW, what do the codes give in the manual?

 

If I run a jumper so only the orange wire is plugged into the fan and run a hot wire straight form the battery to the fan blue wire, fan works and is adjustable high to low, off and on, from control panel. So not using blue/white harness wire at all.
This is with the right fan, have not tried the right one yet.
Working on 1997 XJ6 X300

XJS is at a body shop, not running getting some sheet metal replaced underneath. Something decided to chew on some wires and the 2 wires going to the distributor underneath are chewed thru almost where they go into the distributor. So when I get it back I have to remove the fuel system (rebuild it while its out) remove cruise control unit and A/C/ compressor so I can pull distributor, fix 2 wires and change plugs.
But, it's a V-12 and I really look forward to playing with it.

This XJ6 unfortunately is my wifes daily driver, and with no fan, there is no A/C/ and we live in Florida...

 

.

 

Yeah, dude. I certainly understand the pressure of the wife's daily driver. especially the ac!
The reason I keep asking about the XJ6 is because I do not see a power resistor (or reostat) on the XJ6 diagram and I understood you to report you had changed it.
Now, can you identify the relay I mentioned earlier in the right kickboard? Either it is not being turned on, it is bad, or the feed to it is bad (fuse). I assume you have checked the fuses. Are you sure?

 

Well, I can hear the relays click at low and high speed. Plus with that blue wire bypassed, the fan turns up and down.
The resistor is on top of the right side fan, but controls both sides. I have been told by several people that it is the common thing to go bad. I replaced with one from a working system out of a parts car and then bought a brand new one.
Every single fuse in the right side heel board is good. Checked them all just in case I was off as to which one was for the blowers.
Also the manual shows the relays also effect the power seats. Both seats work just fine.
And one of the fuses also runs the cigarette lighter. I use it for cell phone charger and it works fine as well.

 

Relay CA58 only feeds power to the fan. It's contacts are in the circuit for the blue/white wire. It is listed as in the kickpanel, which is in the front, not in thre rear seat heelpanel. If relay 58 is not pulled in, or if it has bad contactsm, or if its supply power is gone, the sysmptoms would EXACTLY match yours.

 

Where is it....I have looked many times for it in the kick panel area. My parts car I gutted the entire passenger area, air bag, floor panels, etc. and never saw a relay.
I assume that is the "Blue Relay Kickboard" that I have been trying to locate all along.
Any ideas?
The only thing that looks like a relay is the fuel cutoff switch,

I Have copies of a diagram from 1994 and 1997 ...they are identical and neither show a relay behind kick panel...but do show optional windsheild heater relays on drivers side behind kick panel. But I do not have those either.

 

Ron:
The pdf of the paper manual I have defined the relay location as "RH Kickboard". The JTIS manual says RH HEELBOARD, which is the panel in the heel area of the right hand rear seat. JTIS even shows a diagram, and the relays in question ar to the right of the panel area as you face the rear of the car (or the left side of the panel). Sorry about the confusion.

 

ok....that helps, cause I have had more than one person say kick panel...and there is defintely no relays behind the kick panel.
I know the High.Low relays are good...I will replace all the others in that panel and go from there.
Thanks alot for your help

 

All Black relays with Blue stripes are good...2 relays not on the diagrams, one is grey (directly on the fue panel) one is brown. The brown one says "Ford" and is in the middle of the Black/Blue relays.

 

Good? Are the blower motor supply relays pulled in? If so, why do they not supply 12 volts to the positive (blue/ white as I recall) motor leads? If they are not pulled in, then why not? Your codes MIGHT very well indicate some module problem, but riught now you are looking to see if the relays are energized. The relays in question are apparently the rightmost two while looking backwards.