MERKUR SCORPIO BLOWER MOTOR

REMOVAL , TESTING AND REPLACEMENT  PROCEDURE

Original Author: Bob Iversen (Bob_Iversen@McKinsey.com)  - 2/99

(Note:  XR summary below - KT)

1) Assuming your blower fan is not producing any air you would want to  perform a couple of tests to pinpoint the problem. Locate the air box located at  the center of the windshield under the hood between the fire wall and a metal  plate. There is what appears to be a cap on the top with 3 phillips head screws.  Remove the screws and pry up on the lid from the front to break it loose from  the adhesive. Underneath the plastic lid is the Blower motor control module  which amounts to nothing more than a bunch of resistors in series that modulate  the voltage to the blower motor. There is an electrical plug attached to the  module with 5 wires. Disconnect the plug and set the module and lid aside.

The black and red wire on the left is the hot wire in from the dash board.  The blue and yellow wire is an exciter wire that operates the module with a  small amount of voltage coming in. The brown wire on the left is the blower  motor ground wire that goes to the ground brushes. The black and red wire next  to it is the hot wire that goes to the positive brushes on the blower motor. The  brown wire at the far right is the system ground wire that screws to the body of  the car. With the key on and the EATC in auto position you should get 12 volts  from the red and black wire on the left and some voltage from the blue and  yellow wire. If you don't get voltage on these wires you have an input problem.  Now, if you get input voltage, you can turn off the key and plug the module back  in. Then, with the key on and the EATC in auto try to stick the positive probe  to your multi meter into the other red and black wire (the one between the 2  browns). You should get a reading of 6-10 volts. If you do, the module is  working. Make sure you have a good ground for this test. So far you have tested  for input voltage to the module and output voltage from the module. If you pass  both these tests you definitely have a blower motor problem. If you cannot get  any voltage on the second test unplug the module. Then with the key on and the  EATC in auto, jumper the 2 brown wires to get ground and jumper the 2 black and  red wires to get voltage to the blower motor. If the blower motor runs you have  a module problem and you can either work on that, install a remote switch or  leave the blower jumpered and it will run all the time. Again, if the test  fails, make sure to test the blower motor with a ground from the battery or  engine block just to be sure you have a good ground.

2) So now lets assume your problem is the common one where you have voltage  coming into and out of the module and the blower motor still will not turn. What  to do? First curse any German engineer that works for your employer. This will  make you feel better. Then give the wife your credit card send her on her way  shopping and call your buddy to come help you for the next 4-5 hours.

3) Remove the hood. You will thank me later for suggesting this! It is simple  but takes 2 people. There are 2 bolts on either side that attach the hood to the  hinges. (Note: I recommend scribing a thin line around each hinge, in the  paint, so you can tell exactly where the hinge and hood align when it is time to  re-install the hood....makes it much easier, and will save you some time as well  - Ken). Also be sure to disconnect and plug the windshield wiper fluid  reservoir and disconnect the under hood courtesy light. Put the hood in a safe  place where it will not fall or be stepped on.

3) Remove the center section of the metal plate. Peel the weather stripping  back off of the metal plate and you will see where it is seamed on both sides.  There are 2 nuts top and bottom near each seam that attach the center of the  plate to the 2 ends of the plate and the fire wall. To get to the ones on the  passenger side you must first remove the battery.

This is by far the most difficult step so take your time. Once the battery is  removed the 2 nuts on the passenger side come off fairly easily. The two bolts  on the driver side require some dexterity and the displacement of a couple of  things that may be in your way like the electrical module that is attached to  the plate. I suggest not to replace the bottom nut after removal. There are also  a couple of phillips head screws along the bottom of the plate that screw into  the fire wall. One holds a ground strap tang in place so be careful not to loose  it.

4) Now that the plate is loose. Carefully dislodge the wires that run through  channel along the top. There are two more operations to perform before you  remove the plate. Fist remove the clip that holds the thermal vacuum modulator.  (the round thing in the above picture) next remove the metal clips that hold the  top and bottom of the blower air box together. If you do this after you take out  the plate you will loose the clips!

Use a flat tip screwdriver to pry off the clips from the top. A quick  downward and outward snap will do the trick. If you still have the plate in  place don't worry about where the clips go. You will find them underneath the  air box after you remove the plate.

5) You notice in the above picture that the A/C line actually passes through  the metal plate. You can deal with this either of two ways. First you need to  remove the nuts that hold the rubber bushing and retaining plate in place. Next  rotate the plate upward as shown in the next picture.

Now that the plate is up you can either work like this or remove the metal  below the A/C line with a dremel tool to allow you to fully remove the plate.

6) Now that you have made room for yourself the rest is down hill. The next  thing that needs to be done is to cut the airbox as to make a lid. Since all the  clips on the front and sides of the box are removed we can now make a couple of  cuts and take the top off. First cut the legs that are on the inside of the  airbox. They are thin plastic braces that go from the top to the bottom near the  screws that connect the squirrel cage covers. You can clip them at the top with  dikes. We used the dremel tool.

Now that you cut the braces, you need only to make a couple of cuts on the  sides of the box to make a lid. It is not necessary to use the entire exposed  top of the airbox as the lid. You only need to clear the fan (squirrel cage)  covers. I believe we made our cuts right about where the box curves. Starting  from the top cut down with the dremel tool a couple of inches. This is all  clearance we had anyway. The next picture is a bit blurry but what it shows is  that we finished the cuts down the side with an ordinary hack saw blade.

After these cuts are completed, remove the screws inside the box and separate  the top and bottom. The results are shown here. The lid is upside down on the  wind shield. If you look close you can see the braces that were cut and the  holes where the screws came out.

7) At last you can get to the fan! One screw holds it in place with a strap  brace. A noisy fan is either caused by this or some debris or broken fan blades  in the box. Don't just disconnect a noisy fan. It should be easily fixed. Pull  the fan out and thank God your not a German design engineer. Chuck the fan up in  a vice if you have one and look at how simple this monster really is. Clean the  fan motor and brushes with electrical cleaner. You can use brake cleaner on the  commutator. Snap the spring loaded brush holders up and down a few times and  make sure all the connections are clean and there are no splits in the wires or  on those little coils. Make doubly sure that on the positive brush (the one  coming from the black and red wire) there is no part of the wire or coil making  contact with the ground. Note: you'll find that the actual leads from the  positive and negative brushes are both brown like the ground wire. I can assure  you one brush is hot and one is ground. Once clean ,you can lubricate the  bushings with a little oil but be careful not to get in near the brushes. Use  emery cloth on the brushes if you can reach them.

8) now you can test the fan motor on your work bench. Put the center of the  fan motor in your vice. Make sure the fans can spin free. Put a brad (small  nail) in the plug for the center brown and the black and red wire next to it.  Jump these nails to a 12 volt battery or 2 amp charger. If your lucky like I was  the fan will work.

Now if your fan does not work you need to fix or replace it. I do not have  any sources for new fans. However, the fan is just a coil of wire, some magnets  and 2 brushes. Maybe a mom and pop auto electric shop can help.

9) Installing the fan is just the reverse of the other steps, but first test  the fan in place before you install the lid and plate. You can put the fan back  in the air box and secure it. Reinstall the battery and make sure all your  connections are made especially your system ground . Plug the connector into the  module . With the key on and the EATC in auto the fan should spin and the  voltage coming into the fan from the module should be around 8 volts and should  fluctuate as the fan speed changes. Try it in manual in high and low. The  voltage should be different.

My multi meter in the picture reads 8.28 volts the fan was running in auto  about 3/4 speed. Remember the fan module in the Merkur is not preset it is  infinite speed.

10) after you reinstall the lid use some black duct tape to seal the cuts  down the sides.

When you reinstall the clips around the airbox, put the long ends up. This is  the opposite of how they were but they will come off easier if you ever need to  service the fan again.

Original Author: Bob Iversen  (Bob_Iversen@McKinsey.com)

XR procedure from:

John Cullen, Jr." <jcullen@EPIX.NET> 1/97

- Disconnect the battery, remove access covers, wires, resistor pack.

- The blower box is like a suitcase. The top has a panel that can be removed;  remove it.

- Hacksaw the top panel opening to the sides of the suitcase on both sides.  This is about a 4 inch cut. I used a loose 24t hacksaw blade. The plastic cuts  like butter.

- Disconnect the lever for the door actuation, loosen the nuts on the door  actuation unit, then get it out of the way.

- Pry off the clips on the halves with a long screwdriver; remove the screws  inside the panel. Then remove 1/2 of the top of the blower housing (the part  that holds the resistor). This took a little wiggling and force. Now you can see  the blower motor. This took about 45 minutes.

- I cut the tangs off where the resistor mounts to help things go together a  little easier. The suitcase has locating pins and screws to hold it together. I  added a little duct tape. 75 minutes I was done.

Last modified: 2/16/99 - KMT