I had an issue that a number of others are experiencing with their 100 series. Four out of six of my gauges worked only about 10% of the time. The rest of the time they were just dead. Research led me to believe that my stepper motors needed replacing. These are little "tomb-shaped" (black in color) motors that are soldered on to the circuit board behind the cluster. The motors look like this:
I was not able to find any DIY material for a fix out on the net - only a couple of sources for a rebuild service @ ~$450. I wanted to fix it myself and save some coin.
I was only able to source the stepper motors from one place - China (via eBay).
So, here's the DIY part - how to access the motors and replace them.
***TOOLS NEEDED***
- phillips head screw driver
- painter's tape
- sharp pencil/ball point pen
- soldering iron
- desoldering wick
- silver solder
***PARTS NEEDED***
- 2x (speedo and tach) Toyota 4500 4700 Prado Stepper Motor PPE+PS 6S | eBay
-4x (temp, oil pressure, volts, fuel) https://www.ebay.com/itm/Toyota-4500-4700-Prado-Opel-Mitsubishi-Galant-Lexus-Stepper-Motor-PPE-PS-6G-6S/263824150936?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
1. remove your cluster. Here's a pretty good video:
2. begin removing all the little goldish colored screws you can put your phillips head screwdriver on. With the exception of four screws located just beneath the clear, protective "glass", these are all the same size so no need to keep track of where they went. They all need to come out.
3. remove the white plastic "backing" that protects the rear of the circuit board (only 6 or so screws holding this on)
4. continue to remove any additional screws 3. (above) gave you access to.
5. separate the clear glass from the cluster - there are a couple of little tabs which hold the clear piece on after you've removed screws
6. VERY IMPORTANT - cut six small pieces of painters tape and put them on the face of the gauges where the needles bottom out. Mark the exact location of where the you feel resistance when rotating the needle counter clockwise (clockwise in the case of the temp and oil pressure). There is no "peg" that these needles bottom out on. where the gauges stop is based on the internals of the stepper motors and where the needle is indexed on the tiny shaft that drives the needle.
See below
7. After you've marked where your needles stop, rotate them slightly past that point and pull them off their posts. They will slide off the little shaft relatively easily.
8. Remove the left side black plastic "face" that the speedometer is printed on. There are some small tabs that hold it on. Taking this off gives you access to the LCD of the odometer.
9. Flip cluster over so you're looking at the back and ensure all screws are removed.
10. paying attention to the tabs holding the circuit board to the cluster housing and pulling them back where necessary, remove the circuit board form the cluster housing. The odometer LCD will self-remove during this process. Don't freak out - you just push this the multi-pin seat when re-installing.
11. see opposite side of the circuit board. This is where the stepper motors are held on to the board with six solder points each and two small "feet" that go through the board and clip the motor into place. See where my pencil is pointing? These are what's holding the motors on:
12. heat up your soldering iron and desolder (using the wick) all 36 (6 points x 6 motors) soldered contacts. You can youtube how to do this.
13. remove the stepper motors
14. solder in the new ones
15+ do the reverse of the above. The only part that requires thought is re-installation of the needles on the stepper motor shafts. After you've pushed the needles down on to the shafts, you'll need to rotate the fuel, volts, tach and speedo counterclockwise until you feel resistance. This is the integrated stopping poing. You'll continue to rotate the needle until the tip lines up with the marks you made on the painters tape. You'll do the same but rotation should be clockwise for the oil pressure and temp.
Here's a little video I shot when it was all disassembled.
I was not able to find any DIY material for a fix out on the net - only a couple of sources for a rebuild service @ ~$450. I wanted to fix it myself and save some coin.
I was only able to source the stepper motors from one place - China (via eBay).
So, here's the DIY part - how to access the motors and replace them.
***TOOLS NEEDED***
- phillips head screw driver
- painter's tape
- sharp pencil/ball point pen
- soldering iron
- desoldering wick
- silver solder
***PARTS NEEDED***
- 2x (speedo and tach) Toyota 4500 4700 Prado Stepper Motor PPE+PS 6S | eBay
-4x (temp, oil pressure, volts, fuel) https://www.ebay.com/itm/Toyota-4500-4700-Prado-Opel-Mitsubishi-Galant-Lexus-Stepper-Motor-PPE-PS-6G-6S/263824150936?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
1. remove your cluster. Here's a pretty good video:
2. begin removing all the little goldish colored screws you can put your phillips head screwdriver on. With the exception of four screws located just beneath the clear, protective "glass", these are all the same size so no need to keep track of where they went. They all need to come out.
3. remove the white plastic "backing" that protects the rear of the circuit board (only 6 or so screws holding this on)
4. continue to remove any additional screws 3. (above) gave you access to.
5. separate the clear glass from the cluster - there are a couple of little tabs which hold the clear piece on after you've removed screws
6. VERY IMPORTANT - cut six small pieces of painters tape and put them on the face of the gauges where the needles bottom out. Mark the exact location of where the you feel resistance when rotating the needle counter clockwise (clockwise in the case of the temp and oil pressure). There is no "peg" that these needles bottom out on. where the gauges stop is based on the internals of the stepper motors and where the needle is indexed on the tiny shaft that drives the needle.
See below
7. After you've marked where your needles stop, rotate them slightly past that point and pull them off their posts. They will slide off the little shaft relatively easily.
8. Remove the left side black plastic "face" that the speedometer is printed on. There are some small tabs that hold it on. Taking this off gives you access to the LCD of the odometer.
9. Flip cluster over so you're looking at the back and ensure all screws are removed.
10. paying attention to the tabs holding the circuit board to the cluster housing and pulling them back where necessary, remove the circuit board form the cluster housing. The odometer LCD will self-remove during this process. Don't freak out - you just push this the multi-pin seat when re-installing.
11. see opposite side of the circuit board. This is where the stepper motors are held on to the board with six solder points each and two small "feet" that go through the board and clip the motor into place. See where my pencil is pointing? These are what's holding the motors on:
12. heat up your soldering iron and desolder (using the wick) all 36 (6 points x 6 motors) soldered contacts. You can youtube how to do this.
13. remove the stepper motors
14. solder in the new ones
15+ do the reverse of the above. The only part that requires thought is re-installation of the needles on the stepper motor shafts. After you've pushed the needles down on to the shafts, you'll need to rotate the fuel, volts, tach and speedo counterclockwise until you feel resistance. This is the integrated stopping poing. You'll continue to rotate the needle until the tip lines up with the marks you made on the painters tape. You'll do the same but rotation should be clockwise for the oil pressure and temp.
Here's a little video I shot when it was all disassembled.
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