Legionofon

Ok so there is no clear tutorial on the LS forum as far as I can find I did this fix tonight and all I can say is NICE!

So here is my step by step, sorry for no pictures

Parts needed

25v 10uf Capacitor (RadioShack carries 35v 10uf these work)
16v 10uf Capacitor (RadioShack carries this)
50v 4.7uf Capacitor (RadioShack has this it’s quite big)
Soldering Iron (with as small and sharp a tip as possible I had a 25 watt with a 15 watt tip from RadioShack)
De-Solder Braid
.015 Silver Solder

1. Tilt the steering wheel all the way down, there are 3 Phillips screws on the cluster trim remove and pull the trim from the bottom up but not away, reach in and un-clip the 2 connectors on the left and right side and pull the trim out.

2. There are 4 screws in WHITE plastic (do not remove the screws in black plastic) Unscrew and keep these with your trim screws they are identical so no need to separate them, slide the cluster out from the left side as far as the wires allow. There are 3 connectors on the back every time you disconnect one you can move the cluster a little further out to make it easier. Pull out all 3 and take to your work bench and get ready for some work.

3. Follow These Instructions for component disassembly, except you need to pull off the ribbon cables connecting the 2 boards, there is a plastic retainer holding the ribbon against the connectors, pull up on them and they should release. Now the 2nd board has 6 silver screws KEEP THESE IN ORDER and 1 brown screw. there are 5 connectors running to the board gently disconnect these, now that leaves the 2 ribbon cables from the dash lights these come out just like the 1st boards cables pop up the retainer and they come out.

4. Now that we have the circuit boards out you need to get some wire cutters out and crush these 3 caps (your new caps will probably not look like the OE ones).

There should be 2 little wires left on the board put your soldering iron on them and they should de-solder and be removable. Now use the de-soldering wire and suck up the left over solder on the pads and reapply new solder. Get your caps out and trim the leads (remember that the shorter one is negative) carefully solder them to the board (don't melt any of the plastic around the solder pads).

Rebuild the cluster exactly the same way you disassembled it, keep all screws in the right place!!!

Go plug it back in and there ya go you have a working gas gauge!

LiCelsior

iTrader: (32)

very nice job, im guessing u used the stickied thread.

Legionofon

http://us.lexusownersclub.com/forums...showtopic=5822

used that, but it was sorta vague so I thought I would detail it up a bit

Legionofon

also a side note, if you want to fix your tach being miss aligned you have to put the cluster in with the tinted plastic off start your car and let it warm and idle, pull gently on the tach needle, move it to where you think it needs to be 650ish, and push it gently back in, sadly its a crappy fix and im ashamed of it I wish I could give you better but without tearing into my cluster to figure out more stuff I cant write a good tutorial for it... If someone wants to send me a junk/spare cluster for me to tear down and inspect I would gladly write a tutorial up if I can figure out a way to fix it...

Also, on the needles... they appear to be some sort of fluorescent or similar technology, its actually quite interesting, when I was re aligning my tach I touched the needle of the speedo and it lit all the way up but when i took my finger off it turned back off, there seems to be some broken connection on the outside of the tube, the black tape thats behind the needle carries current because I played with it and it arched and burned me!! I would be very interested to tear one of these down without risking my own cars dash...

williamb82

ok, i did this mod, gauges lit fine for a couple days now dont light at all. im gonna recheck the soldier joints. main problem is the fuel gauge is acting goofy. at first it went all the way to full. after 1min it dropped to empty and gas light came on and stayed. i turned the key off and back on. it went to 3/4 full and after 1min dropped again. turned the key off and on again and now every time it goes a lil above the e and stops. did you guys use electrolytic caps for all 3? 1 of the caps i used in the fuel gauge circuit wasnt electrolytic. could that be the issue. i didnt realize till i noticed this problem and checked the packages.

williamb82

ok, c212 was blown. i guess the cap i used i installed backwards. all it had notating polarity was an arrow. found my box of ic's, caps, inductors, resistors etc.. and had the cap i needed. installed it and now all gauges light up and stay lit. left it on for ~10min and no issues. also so far the gas gauge stays in the same spot and doesnt drop after a min or so. though it is showing almost full though i thought the tank was almost empty. im gonna try and check the level in it tonight to see. maybe i got lucky and the seller left almost a full tank since the gas gauge wasnt working.


btw, does anyone know what i/c's need swapped if i use the boards from a kph cluster? i want it to show miles on the odometer, not kilomoters if i do buy it. also would help anyone that changes their cluster ro one from a junkyard so they wont have to pay the exspensive "reprogramming" charge to show the correct mileage.

williamb82

i did this fix awhile back, but the gas gauge still isnt working correctly. i checked the connections at the tank. they are good. the gas needle just jumps all over the place.

PureDrifter

iTrader: (10)

did you test the sending unit in the tank?

williamb82

resistances looked fine. did it days ago when it was mentioned in another thread.

williamb82

ok, i changed the fuel sending unit. no change in the fuel gauge at all. still bounces all over the place at random.

zukikat

When I bought my 94 LS the needles strobed sometimes and didn't light at all the rest of the time, the gauges didn't light at all most of the time and rarely stayed lit very long unless I played with the dimmer **** every so often, the gas gauge mostly sat on E but occasionally twitched up to just above 1/4 at random, the temp gauge eventually went from well below C to about 1/2 way between the C mark and the first mark above it, and the speedo and tach moved normally but were usually hard or impossible to see and getting to actually see what they were pointing at was a rare treat...
The shifter panel, climate panel, stereo, and window switches on the driver's door also would go completely dark when the parking lights/headlights were on.

I replaced those 3 capacitors with "polarized" electrolytic capacitors of identical uF's and either identical or slightly higher voltages based on my local radio shack's inventory and the gas gauge has been coming right on up to level the moment I turn the key on and working flawlessly all week, the speedo and tach now occasionally require a rap on the top of the dash to get them to show anything other than zero, and the temp gauge is still only showing just above the C mark even when all warmed up.
Plus now to my suprise the shifter panel, climate panel, factory stereo, and driver's door window switches all light up and adjustably dim along with the dash lights when I turn the headlights/parking lights on at night, YAY!!!
The quality of the radio shack capacitors may prove to make my illumination joy short lived but it's no biggie for me to do it again if necessary...

I also learned that my low fuel light works properly as the day after I bought the car and replaced those three capacitors I drove about 50 miles and went from 1/4 tank showing to 1/8 tank showing and the low fuel light came on which required 19.5 gallons to fill the tank.

I wonder if you pissed off something else in the fuel gauge circuit with the capacitors installed backwards as they ARE polarity sensitive devices in those circuits. I'm suprised they didn't explode as that's what usually happens when you install a polarized capacitor backwards.

williamb82

negative. i swapped in another cluster i have as a spare. same exact issue. im gonna trace the wires from the sending unit to the cluster when i have a chance. im guessing the wire insulation is cut somewhere or the wire itself is cut. previous owner rigged alot of crap on the car that ive fixed already. so wouldnt surprise me if the wires got messed up somehow by him. its the only thing left.