How to replace the Blower Motor WITHOUT removing the A/C refrigerant!!!

Old 07-16-2011, 11:21 AM
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Default How to replace the Blower Motor WITHOUT removing the A/C refrigerant!!!

This is the tutorial on how to replace and test your Blower Motor WITHOUT removing your accumulator or removing any refrigerant (if' you're gentle handed).

****Caution. This process takes a carefull application of motion. You can't be a "Bang the square peg in the triangular hole" type of person to do this. You don't have to be a brain surgeon either. Just be gentle. There is a potential to leak some or all refrigerant if your O-rings are too old or dry rotted. My truck is a 99' and I have 137K miles on it.****

The tools required are:

-1/4" drive mini ratchet set (to remove the Accumulator Bracket) with that "pivot joint attachment" and short/long extensions
-5/16" socket (for fan bolts)
-Standard pliers (may not need this if you have the pivot joint attachment for the ratchet. I had a poor socket set, so it would have gone WAY better if I had those pivot joints with me (I'm not sure if that's the TECHNICAL NAME ) attachments and the short/long extensions.
-Flashlight (helps since its dark way back in there)

Time required:

1-2 hours depending on skill level. Maybe less.

Why are you doing this?

I was driving down the road with my A/c working great as normal. All of a sudden, it started blowing warm. No noise, nothing. I kept driving about 3 miles like that HOPING that it was going to "catch back up" but it didn't. You see I replaced a section of vacuum tubing the day before since the old piece was cracked. I thought maybe this ordeal was vacuum related. Then I started to smell smoke. Didn't see any, just smelled "burning". I started to panic. Next thing I know (again w/o noise) I see smoke coming out from under the Passenger Side dash. YIKES!!! I was on the highway doing 65. I quickly pulled over. The smoke was gone by then, the blower didn't work AT ANY SPEED.

I did some research here and narrowed it down (without tearing anything up yet) to either the Blower Motor or Blower Motor Resistor-BMR (or both).

Further reading yielded that in the BMR failed, the fan WOULD WORK ON HIGH SPEED! This was NOT happening. That's also in the FSM for conformation. So it HAD to be the BM.

I got this advice from a buddy who is a 30-year Master ASE Certified Toyota (gasp...) Mechanic. I told him the FSM said I HAD to remove the refrigerant AND Accumulator to get to the BM on a 98+ Cherokee with A/C. He looked right at me and said NO. Here is the steps I followed from him to replace the motor. I also include pics of me checking the old and new motor for continuity.

****Caution. This process takes a carefull application of motion. You can't be a "Bang the square peg in the triangular hole" type of person to do this. You don't have to be a brain surgeon either. JUST be gentle. There is a potential to leak some or all refrigerant if your O-rings are too old or dry rotted. My truck is a 99' and I have 137K miles on it. I asked the Yota mechanic if this were his truck, what would he do. WITHOUT hesitation, he said he'd do THIS. I didn't pay this guy a dime for this advice and his boss is my friend, so I trust him****

This is what we started with. Notice the fan motor way back there in the firewall:



Step 1:

-Remove the Accumulator bracket, no picture here. You'll figure it out. The Accumulator is the SCUBA tank looking (Black) piece on the Passenger Side of the rear most portion in the engine compartment. Hint-it's near your antenna. I forgot the size socket I used for that but it's very easy to access. I'm just getting used to SAE. Everything recently has been metric up until now. Easy!

Step 2:

-Remove the electrical clip off the Accumulator but depressing on the "lock" found on most all clips of this type. Easy!



Step 3:

-Remove off the rubber isolator, this vacuum device, to get it out of the way. Sorry-don't know the name of it so let's call it a Whisker-do. Easy!



Step 4:

-This is the O-ring coupler that we will be carefully pivoting the Accumulator out of the way with. It is the Black A/C line that is on the left. DO NOT try to remove the clip. That could leak R134A everywhere.



Step 5:

-There are three 5/16" screws (sheet metal type) that hold the BM in. Remove those. They are too hard to photograph. You'll be able to see them with the flashlight. Place them somewhere safe. You will need a combination of the 5/16" socket, extensions and the pivot joint to access them. This was the most time consuming part of the job. It's kind of tight in there but saves money!!!

Step 6:

-Carefully rotate the Accumulator by grabbing the bottom, and letting the unit "rotate" bottoms up so that it is now even with the horizon (or higher). Unclip or carefully remove the Main Wiring Harness zip-ties to move the harness out of your way. I was able to pry up on one and reuse it. The other I cut VERY close to the lock on the zip tie and STIIL was able to use the "shorter" part of it and secure the zip tie by collapsing the wire loom a little more. Now, curse as you bang your knuckles and fingers on edges you didn't even know exist. Look over your shoulder at you Mechanic's glove sitting on your toolbox and think, "Why didn't I have those on....". Then wiggle the BM plug out of the BM. It is a Tension style plug with no locks, so grab it by the base and keep rocking it forward and back-NOT left to right so much. It will pop off.

The old BM WILL come out. TRUST ME. You will have to pretend you are taking a jar of honey from a sleeping bear, but with moving the wiring harness out of the way, AND rotating the Accumulator up even higher with your "third hand"-read forearm, lol; It will come out.



Step 7:

-You don't HAVE to do this, but I wanted to make SURE I wasn't doing all this in vein. I tested the continuity on the old and new motor once they were out. The OLD one showed OL.



Them NEW one showed



I don't think yours has to show that specific resistance, but you can see the other motor was fried!

Step 8:

-Wiggle the new motor back in-YES IT WILL FIT. Make sure the BM plug connector is facing up around the 1-2 O'clock position. Yes, the wire for that comes from the same hole the BM is going in. NOTE-you are going to have to wiggle the bottom "tabs" of the BM in behind the "ridge" in the firewall. I though they sold me the wrong motor at first, until I saw I had to spend more work wiggling it and pushing it back to the mounting plate. The 4-5 O’clock BM tab gave me the hardest time here!

Grab those 5/16" bolt/screws and secure the BM to the mounting plate.
Connect the BM plug. HINT-It will ONLY fit on one way!!!

Step 9:

-Carefully rotate the Accumulator back down. Attach the bracket.

Step 10:

-Hook the plug that you disconnected from the Accumulator back up.
-Attach the vacuum "Whisker-do" back to the rubber isolator mounting point on the firewall.

Step 10:

-Re-attach the main wiring harness back to the zip ties.

Step 11:

-Check your BM for operation and if not working, look at ALL fuses related to it. HINT-my BM burnt up with NO NOISE and WITHOUT burning a single fuse! So I didn't have to replace a fuse surprisingly. Go grab a beer and marvel at the ability for man to provide for himself!!!

Last edited by Vincenza V; 07-16-2011 at 11:27 AM.
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Old 08-01-2011, 02:04 PM
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Fantastic! My blower just died yesterday on my 99 also. I will look tonight to see what I am up against, very good write up, it does not look to bad. Thank you for your time....
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Old 08-01-2011, 04:33 PM
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Haha! I love the names you come up with for things!
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Old 08-03-2011, 07:55 PM
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Thank you gentlemen! You do have to add a "little" humor in all tutorials! I believe it's a rule some where. It was really an easy fix. I've gotten so much from these forums that I want to give back anyway I can and will accomplish more write-up as I can!
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