I suspected that the alternator on my 2011 RX350 needed replacing or repair. The symptoms were that the battery gradually ran down and the alternator couldn't bring it back up to full charge or took too long to do it.
I even suspected that the car ran off the battery because at some point, the electric power steering failed to operate, possible because the voltage got too low as the battery depleted.
I've seen this type of thing before when the regulator or rectifiers/diodes on the alternator failed and a replacement of the regulator brought the alternator back to working condition. So I bit the bullet and did this overly complicated procedure made so complicated because our engine compartments are so small and the engine is turned 90 degrees.

Because I'm just a DIYing amateur, what I like to do for any of my repairs is to watch a number of videos on how to do it, choose the best one and then document it, step by step so that I can just refer to my printed document as I do the job instead of going back to my computer to rewatch the video all the time or look at the tiny screen of a cellphone next to me. Further, I add relevant and more clear steps gleaned from other videos.

Posting this here in case it will help someone else in the future. Sorry for the formatting, it's a straight copy and paste from my Google Docs procedure document.

Tools needed:

• 5mm hex wrench
  
• 10mm wrench
  
• 10mm socket on 1/4 ratchet
  
• 14mm socket on a 3/8 ratchet
  
• 12mm deep socket
  
• 6-inch 3/8 ratchet extension
  
• Cheater pipe
  
• Pick
  
• #2 Philips screwdriver
  
• Flat blade screwdriver (6-inches)
  
• crowbar
  
• Coolant refill and purge kit (funnel and correct adapter for RX350 radiator filler neck)
  
• Tire changing tools (breaker bar, correct socket, torque wrench, etc.)
  

Best video for how to remove and re-install an RX350 alternator by "How to Automotive"

You Tube

A video by "TRQ" with different points of view (not necessarily better):

You Tube

• Useful for how to pull various electrical connectors, e.g., which buttons on the connector to push

Procedure (as per this video:

You Tube

)

1. Remove all 3 front black plastic covers over the engine
   
2. Remove top silver engine cover
   
3. Use a 10mm wrench to disconnect the negative battery cable and secure it off to the side.
   
4. Jack up the front of the car and put it on 2 jack stands (I used just one on the passenger side with the jack near it as a backup)
   
5. Remove passenger tire
   
6. Remove 2 x 10mm bolts that hold the plastic access cover; it will still be held in place by a plastic clip towards the front of the car
   
7. Remove the front underbody splash guard by removing some 10mm bolts and clips
   
8. Remove the clip holding the plastic access cover in step 6 (press in on the centre piece of the clip with a pick or small screwdriver and the clip will come free) and remove the cover
   
9. Put a 14mm socket onto 3/8 ratchet and with a cheater pipe, turn the tensioner counter clockwise and put a 5mm allen key into a hole on the tensioner and into a corresponding slot to hold it open
   
10. There is a 14mm bolt to the right of the tensioner roller. This is the alternator bottom bolt. Remove that bolt using a 3/8 ratchet, a normal 14mm socket AND a cheater pipe
    1. A Commenter said: "For the bottom bolt, I found it easier to attach the socket from the underside and use a breaker bar from the topside to break that bolt loose. Wasnt enough room to get leverage from underneath. " I didn't need to do this.
       
    2. Another commenter said: "A suggestion on removal of the first bolt (under the tension pulley) ... Wait until the radiator is loose, and approach it from above ... I could not get leverage to loosen from below (2011 / 155K) and after an hour of effort (and before rounding off the head), moved on ... From above, and approaching front-to-back, could keep the bar perpendicular to the bolt and get some *** behind it ." I didn't need this either and could see how this could be done; maybe he removed the coolant hose that was in the way.
       
11. Remove the front grill
    1. Using a #2 phillips screwdriver, remove 2 plastic clips on the left; one is under the rubber molding.
       
    2. Remove 1 plastic clip in the middle of the grill
       
    3. Remove 2 plastic clips on the right, one is under the rubber molding
       
    4. Gently pull the top of the grill towards the front of the car to swing it clear
       
    5. Work your fingers down the right side of the grill to pull it past some clips or something that is holding the grill. Gently but firmly yank on it.
       
    6. Slide your fingers under the grill to work it free of some clips
       
    7. Work your fingers to the left of the grill and the up the left side until the grill comes loose.
       
    8. A video that shows this:
       You Tube
       
       

1. Remove air snorkel by removing 2 x 10mm bolts and begin taking it out. There will be 2 vacuum hoses that are clipped to the snorkel; unclip them and the snorkel will come free. Set aside along with the 2 bolts
   
2. Remove the lower smaller plastic snorkel piece that's held with a single 10mm bolt. Set it aside along with the bolt. 2 Vacuumhoses needed to be unclipped from this before it comes out.
   
3. Take out the bottom front plastic splash guard so that coolant can drain down and out of the car.
   
4. Get a bucket or a tub that will hold at least 2 litres of liquid and put it under the radiator petcock (yellow plastic **** below the radiator). I used a standard bucket. Make sure it's clean because you will be pouring it back into the radiator at the end of this procedure.
   
5. Turn the petcock and drain 1.5 or more litres of coolant out; take radiator cap off to help the coolant drain faster. The stream will hit a beam and turn into 3 streams. Make sure your bucket catches it all. Note the video said "a few ounces of coolant need to be drain". No. You need at least 1.5 litres to be drained, otherwise it will spill out when you remove the upper radiator hose later.
   
6. Use a pair of pliers and maybe a flat-blade screwdriver to squeeze the clamp that holds the upper radiator hose to the radiator and slide it back a couple of inches
   
7. Use a pick or a flat-blade screwdriver to break the seal that the radiator pipe has on the radiator neck.
   
8. Pull the radiator hose off and push it back and tuck it out of the way. A convenient "holder" is the airbox entrance hole left by one of the snorkels.
   
9. Remove the coolant reservoir by removing the 10mm bolt. You also need to remove the coolant overflow tube from the radiator filler neck and unclip it in 2 places along the top of the radiator. Set the coolant reservoir aside.
   
10. Remove the radiator fan assembly
    1. Unclip the big connector for the power
       
    2. Use a 10mm wrench and slip it over each of 3 wire loom holders so that you can free them easier. "Sometimes a little circular motion was needed"
       
    3. Once the wire loom is loosened, flip it out of the way towards the battery
       
    4. Unclip the transmission cooler line at the bottom of the fan. Use a pick tool to open the clip. Push the cooler line towards the engine to get it away from the fan
       
    5. Remove the 2x 10mm bolts that hold the fan assembly. They are at the top left and right of the fan assembly.
       
    6. Pinch the clip in the middle that holds the fan assembly to the front of the car to free the fan assembly and then push the fan assembly towards the engine.
       
    7. Slowly work the fan assembly loose by rocking it back and forth and left to right until it comes free of the clips at the bottom that hold it down. You will need to extricate the fan assembly from the various hoses that will want to snag it. Do this carefully and it will come free.
       
11. Remove the radiator core support
    1. Remove 2 x 10 mm bolts from the left of the core support, then the 2 x 10mm bolts from the right of the core support
       
    2. Remove the front licence plate.
       
    3. Remove the 10mm bolt at the end of a long downward bracket in the middle of the support by going through the area of the grill just above the bumper.
       
    4. Use a 10mm box-end wrench to unclip an electrical connector.
       
    5. Unclip the wiring from each of the 2 horns
       
    6. Follow the horn wiring down to the bracket and use that 10mm wrench trick above to unclip the horn wires from the bracket
       
    7. Pull the radiator core support up, rotate it to the right, and lay it on top of the engine. This is because the hood release cable is still attached to it on the right side and thus the support can't be removed. My notes during the procedure say there might be a clip in the middle that needs to be removed, I can't remember the details.
       
12. Flex the radiator forward a few inches and that will give you enough room to remove the alternator
    
13. Put a piece of cardboard cut to the shape of the radiator between the radiator and the alternator to protect the radiator fins and core from the heavy alternator when it gets removed.
    
14. On the alternator, pull back the rubber boot that protects the top thick cable to the alternator. Loosen the 10mm nut and remove the cable. Put the nut back onto the alternator stud for safe keeping.
    
15. On the alternator, there is a 10mm bolt holding the wiring loom to the alternator, take the bolt off (see TRQ video)
    
16. On the alternator, squeeze a big plastic clip that holds the bottom thick cable and pull it off the alternator. My fingers weren't strong enough, so I used some channel lock pliers to push the button.
    
17. Create as much slack in the wire loom as possible by unclipping the wire loom from the engine by pulling on a tab on the big clip to detach the clip from the engine. Pull back on the wire loom.
    
18. Remove the similar clip higher up on the wire loom near the cam phaser.
    
19. The video suggests unplugging the AC compressor too but I didn't really show how it could be done and I found this was not needed.
    
20. Take the alternator top bolt off. 14mm. You may need to push a radiator hose a little bit out of the way. I used a 14mm deep hex socket and a 1/2 in ratchet to get past the radiator hose.
    
21. Remove the L-bracket of the alternator by removing a 12mm nut off a stud on the engine. You will need a mirror to see the bolt. It's deep in there. It is NOT the 1st nut on a stud that you see; it's deeper than that one. You remove the 12mm nut with a 6-inch extension and a deep 12mm socket. Apparently, you can also try to remove the nut from below. Removing the nut may remove the stud too. Separate the nut from the stud and be prepared to try to put the stud back. May need a female Torx to do that. I found it easy enough to just use the 6-inch extension and a deep 12mm socket and my nut came free without taking out the stud with it.
    
22. Use a pry bar and gently pry the alternator loose. The position to use to pry is about 1.5 inches above and 1 inch to the left of the stud that the top big cable connects to.
    
23. Once the alternator is loose, you will find another wire loom attached to the L-bracket. Before taking the alternator out, the video suggested to use the 10mm wrench trick to pop the wire loom off the L-bracket. I found that I could free it by manipulating the clip back and forth with the tip of my finger. I couldn't get the wrench in there to do the wrench trick.
    
24. Flex the radiator towards the front of the car and the alternator should now come out. This was the hardest part of the job. Firstly, the alternator is somewhat heavy and so moving it around a limited space where you are leaving over the radiator is not easy. Secondly, the wiring loom and the serpentine belt conspire to hold the alternator in.
    1. So REMOVE THE SERPENTINE BELT FIRST. It took some annoying unwinding and pulling to get it out.
       
    2. Move the wiring loom around to so that the alternator can come out.
       
    3. Take it easy but lots of twisting and turning and rotating to get the alternator past the wiring loom will eventually get it out. It's heavy and so don't take TOO much time because you'll get tired and you'll need your strength to pull it out when it comes free.
       
    4. This was not in the video, but I also loosened the exhaust manifold heat shield by removing 3 x 10mm bolts. The heat shield was snagging the L-bracket, trapping the alternator. Removing the 3 bolts allowed the shield to move to the right enough that it freed the L-bracket.
       
    5. Someone mentioned that taking out the stud for locating the L-bracket can make the alternator removal easier or possible since for him it hung up the alternator. I did not find that I needed to do that.
       
    6. Someone else said "I just couldn’t get that 12mm off the the bracket,I end up removing the 14mm that is screwed to the alternator,". I did not need to do this.
       
    7. Commenter said: "If you replace alternator and it doesn’t start afterwards, check crank sensor wires it’s likely you pulled wires while removing bottom L bracket", so double-check that I didn't pull those wires loose. They are the ones that attach to the L-bracket. Make sure that the ends remain connected to what they are supposed to.
       
25. Take the L-bracket off the alternator, presumably by removing a bolt. I did not need to do this because I took the alternator to a repair shop for repair as opposed to getting it replaced.
    
26. Take the alternator to your shop for repair. They replaced the regulator, brushes, and bearings, declaring it be like new and they even washed it down for me. It was spotless when I got it back. Note: they did test it before doing the repair and it was indeed dead. They showed me where the diode connectors were burnt.
    
27. Once you get it back, put the L-bracket back on it (didn't need to do this since I didn't remove it)
    
28. Reinstall the alternator by lining up the stud with the hole in the L-bracket and slipping it on.
    1. TRQ video says you may need a deadblow hammer to gently tap in the alternator. I did not need to do this
       
29. IMPORTANT NOTE: I could not get the clip for the thick wire under the alternator back onto the L-bracket. Someone thought it might be an AC communications cable; or it may be the wires for the crank sensors; not sure what it was. BUT there is NO WAY to put it back on. I searched every video and NOBODY showed how to do it. I suspect they all tried, failed and then gave up and left it not clipped in but were too sheepish to show their failure in the video. I could see no downside for leaving it unclipped (there are no sharp surfaces to abrade the cable with vibrations) and so I will leave it a tiny bit loose like that.
    
30. Put the 14mm top bolt back on and through the mounts on the alternator. Screw it in a few threads but not totally.
    
31. Go back to the passenger wheel well and put the alternator 14mm bottom bolt in. Similarly, screw it in only a few turns; don't tighten it yet.
    
32. Go under the car and start the 12mm nut that will tighten the L-bracket onto the stud. Start it by hand and screw it in a few turns (but do NOT tighten, otherwise you put stress on the top and bottom alternator bolts and they will be hard to tighten by hand (see next steps))
    
33. Go to the passenger wheel well and tighten the 14mm alternator bottom bolt. Screw it in by hand as much as you can because there's not a lot of room to swing the ratchet. Torque to 30-ft lbs, a bit more than a gentle grunt. I used a cheater pipe and less of a grunt.
    
34. Tighten the alternator top bolt 14mm. Screw it in by hand as much as you can for convenience. Torque to 32 ft-lbs, a bit more than a gentle grunt
    
35. Finish tightening the 12mm nut on the L-bracket with the extension and 12mm deep socket. Torque to good-and-tight.
    
36. Route the serpentine belt around the pulleys properly (consult a diagram). I used a new serpentine belt from a nearby Toyota dealer. Ugh, a bit expensive. But I didn't want a cheap aftermarket one. A tip is to wind the belt around all the pulleys and rollers and leave the loop around the tensioner for last. You may need to twist the belt 90-degrees to slide it to some tight places. Go slowly and it will work. It wasn't as hard as I thought because taking it out was harder. Make sure the belt is seated properly over all the pulleys.
    
37. Use a 3/8 ratchet wrench, a standard 14mm socket plus a cheater pipe to untension the tensioner and remove the allen wrench and then release the tensioner and that will tighten the serpentine belt up
    
38. Plug back the bottom cable into the alternator. Push until you hear a click.
    
39. Connect the top cable and tighten it down with the nut. Put the boot over it.
    
40. Install the 10mm bolt onto the bracket that locked down the wiring harness and bolt it to the alternator
    
41. Clip back the wiring loom with the 2 clips that you loosened before
    
42. Take out the piece of cardboard.
    
43. Take the radiator core support and flip it back into position
    
44. Bolt it back down with the 4 bolts (2 on the left, 2 on the right) and one in the middle
    
45. TRQ video showed an ambient air temp sensor cable that needed to be plugged in near the vertical bracket
    
46. Clip the horn wiring harness back on and then plug the wiring into the 2 horns
    
47. Reinstall the fan assembly by putting the tabs at the bottom of the assembly back into the slots at the bottom of the radiator. Go slow and make sure it fits in properly, not snagging any hoses, etc.
    
48. Pull the fan assembly forward to click it into the clip in the top middle
    
49. Bolt the fan back down with the 2 x 10mm bolts, left and right
    
50. Clip back the wire loom to the fan assembly and plug in the fan wiring to the fans. There are 3 clips that should be clipped back into place to support the wire loom.
    
51. Clip back the transmission fluid hose
    
52. Put the upper radiator hose back onto the neck and place the clamp back into the proper position
    
53. Put the bottom snorkel back in place, making sure it's connected to the air box, but don't bolt it down yet
    
54. Put the coolant reservoir back, seating it into place such that a nipple on it fits into a rubber grommet below. Connect back a coolant overflow hose to the radiator neck if you took that off.
    1. Bolt down the coolant reservoir
       The coolant overflow hose clips back onto the radiator in 2 or 3 places
       
55. Bolt down the lower snorkel with the 10mm bolt
    
56. Clip back the 2 vacuum lines that were previously clipped in this area. Use a flat screwdriver to force the lines into the clips
    
57. Take the upper snorkel and put it back on, making sure the other end is connected to the air box and bolt it on with its 2 x 10mm bolts
    
58. Clip back the 2 vacuum lines that were previously clipped in this area. Use a flat screwdriver to force the lines into the clips
    
59. Put the grill back on, fitting it in properly. Start at with the bottom and make sure all the clips are in properly first. Then push it in on the sides, making sure all the clips are in the holes properly. Put back the 4 x plastic clips, 2 on the left, 2 on the right and the remaining one in the middle.
    
60. Take off the radiator cap and top off the coolant with the coolant replacement kit funnel as well as fill the coolant reservoir to max. Consider taking the opportunity if the age of the coolant is old to do a full coolant drain and fill and purge.
    
61. Put the battery cable back on
    
62. Put the 3 top covers on
    
63. Go to the pax wheel well and put back the serpentine belt access cover with the 2 bots and that plastic clip.
    
64. Put back the underside splash guards
    
65. Put the wheel back on
    
66. Start the engine and see that the voltages are correct (I measured 14 V at engine start but because the battery was full (because I had it on charger while I was swapping the alternator), the voltage soon dropped to 13.7, 13.6, and then to 13.5 V)
    
67. Run the engine long enough such that you can see that the cooling fans come on. For me, I took it for a short drive and when I came back, both cooling fans were spinning. And voltage settled down to 13.4 V.
    
68. If you have a battery testing place near you, go there and get your battery tested in case it was the cause of the alternator failure. My local shop, tested my battery for free.
    
69. The battery testing place's meter may also be able to test the alternator. Mine did and they also tested it for free. The alternator passed.
    

 

Serpentine belt diagram for reinstallation:



Source:
https://share.qclt.com/%E4%B8%B0%E7%...t/00800210.pdf

 

I did a serpentine belt replacement a couple weeks ago. It was harder than I thought lol.
Pulling the tensioner while trying to adjust the belt. Ended up needing my wife's help.

 

Theres a hole where u can lock the tensioner in place by sliding a bolt/allen wrench while u doing belt.

 

Yes, it's in Step 9 of my long-winded description.
And I should mention that it's quite difficult to move the tensioner with a regular ratchet unless you're very strong. I needed a cheater pipe. Some people have a very long-handled ratchet, which would also work.

 

Hmmm. The tensioner may be bad. The force that you have to overcome is the force that is providing the tension in the belt. Too little, the belt will slip and too much wasted energy and shorter life of bearings.

Salim

 

That "How To Automotive" video is excellent. That's what I followed when I did this a couple years ago. It's one tiny deficiency is he forgets to tell you to re clip the trans line (removed at 06:48) back on during reassembly at the end.