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Will this procedure work for a 93 LS400 keyless fob? Thanks

Thanks for the excellent info on the fuel gauge fix. Worked like a champ on my 93 LS400. Any info on fixing poorly illuminated needles. My rpm needle only lights up about 3/4. Any help would be greatly appreciated. Thanks

Hi Folks,

been super busy in last couple of months, hardly had chances to visit the forum. hoped everyone had a wonderful x’mas and new year.

I finally got a chance to tackle the fuel gauge problem on my 94 LS. before the fix, the fuel gauge needle could only go up to 1/3 max even tank was full. so I followed the instruction found here to replace C142/C147 electrolytic capacitors on the big circuit board inside instrument cluster. I’m happy to report it works like a charm! the fuel gauge is back to normal.

*removing cluster and the 3 darn connectors

of course, you must follow Jim Walker’s infamous procedure:

http://www.lexusownersclub.com/Lexus_Circu...ard_Removal.pdf

I found that the biggest pain in the butt was to disconnect 3 connectors (blue, white & orange) from the back of cluster so that you could take the entire cluster out of the car. on each connector, there is a latch to hold the connector tight in the socket. one will have to manage to press the latch inward and pull the connector out at the same time. it was much easier to say than getting it done because there is very little room behind the cluster and the connectors are pretty darn tight. you need to have lots of patience with very strong fingers too!

*removing old capacitors

when you have the bare circuit board on your bench, and begin to remove the bad C142/C147, DO NOT just pull the capacitors out. Be very careful not to damage the circuit trace surrounding them. the capacitor can is surface-mount on the component side of circuit board, and you can’t de-solder it from the bottom of circuit board. the two legs (+/- leads) are too short (entirely covered by the ‘can’) to be de-soldered underneath the capacitor can. What I did was to use a sharp nose pliers and ‘destroyed’/removed the capacitor can first, then the two leads were exposed to be de-soldered.

*new capacitors

the soldering work was not difficult to do, one just needs to use very fine soldering tip and keep your hand steady. the C147 is rated 50V/10uf, and C142 is 25V/4.7uf. however, I couldn’t find 25V/4.7uf at Radio Shack, so I used their 35V (max)/4.7uf, and it works!

(note: the ‘V’ really stands for WVDC). pay attention to the orientation of +/- lead from capacitor can. usually, the ‘-‘ lead is aligned with white band on the capacity can.

*my remaining issues:

1. oil level warning light is on despite engine oil is indeed at proper level. does anyone know which capacity is to control this warning light?  in fact, does anyone have a circuit layout or wiring diagram for the instrument cluster?

2. the coolant temp gauge remains bad on my cluster. I believe it’s the needle itself, not any bad compoenent on circuit board. when I lift other 3 needles (fuel/rpm/tach) by finger and let go, they will return the lowest position immediately in smooth motion, but temp needle won’t do that, it just stuck, and the center dial is somewhat loose and non-responsive. does anyone know how to change out the needle/dial?

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