When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Fix: peridically freezing speedometer & Fuel gauge reading below actual fuel level fi
For the GS300/Aristo '91-'97 (1st Gen)
DISCONNECT THE BATTERY BEFORE ANY GAUGE CLUSTER REMOVAL! - Otherwise the Airbag light will stay on and you will have to perform this reset procedure to turn it off. http://www.lexls.com/tutorials/light...rbaglight.html
If you ever have an issue with filling your fuel tank full and the gauge only reads 3/4 full, half, or less you may have an issue with faulty capacitors in the back of the fuel gauge cluster.
The same issue arose with various lexus models from the 90's regarding with ECU's acting up and their faulty capacitors. This capacitor issue also came about on the ls400's pertaining to incorrect functioning in the fuel gauge, lighting, etc. There is are a few posts here on how to fix the issues.
Well I fixed the issue I was having. My fuel gauge would only read up to 3/4 full after I filled up the tank completely. Even after I would push the needle to full by hand, it would still drop down to 3/4 full or sometimes below empty on a full tank. And my speedometer would sometimes freeze for 1-2 seconds at 40mph on hot days.
Since I changed the faulty ECU capacitors(no visual indication of faultiness) and that made a difference in the engines running, I decided to do the same thing to the gauge cluster's electrolytic capacitors "can capacitors". Instead of just locating only the fuel gauge and speedometer's capacitors, I decided to change all of them. This requires some soldering experience which you can easily learn to do from youtube.com.
____________
To do this I had to disconnect the 3 - ribbon cables from the top of the board, remove the screws that secured the board, disconnected the white cable plug from below, and literally lifted the board up and off of the gauge cluster. This way I could have clear access to the underside of the circuit board to de-solder the capacitors from below. See labeled picture below.
Below is a picture of the gauge cluster circuit board and the placement and rating of each capacitor. Please disregard the yellow and red colored font. There is nothing significant about the colors. This was done for the ease of viewing.
**Note: When re-installing the screws for the gauge cluster board, use a screwdriver and make sure they are snug, NOT tight. If you screw them in tight, the brittle plastic will crack and break. Or even worse (in my case) you may end up ruining the one or more of the 5 long screw metal contacts for either the Fuel gauge or the coolant temperature gauge. And you may end up with a fuel gauge that goes to only 3/4 full when the tank is completely full (only 4 of the 5 screws make electrical contact with the fuel gauge).
Where did you get all of the capacitors? I think I might have to do this now. I don't have too many problems with my ecu or my cluster, but I am thinking preventative maintenance. Nice job on the cluster.
Nice write up!! There are companies that charge alot to to fix the gauges this probably what they are doing to repair them!! This should definitely be a sticky in the DIY section!!
No problem guys. I just went to a local electronics store (Orvac, Rvac or even last resort is radio shack), took it apart, and categorized the capacitance values and voltages that were on the circuit board. I then looked for electrolytic capacitors of the same values on the board, but with higher voltage ratings.
The theory behind seeking a higher voltage rating than what I specified above is that the internal materials and design can handle more than what we will throw at it possibly allowing the parts to last longer than one of the same voltage rating as the stock capacitor.
The store I went to charged me about $1 per capacitor. You can get the capacitors from www.digikey.com or an even better place is www.mouser.com for a whole lot less, but shipping may make it equal the same price.
Some may want to go all out to the extreme and buy tantalum capacitors, but I think that is overkill. I just bought electrolytic capacitors with a higher voltage rating than what was on the board. I think you will be fine in this instance. I will post in a bit the removal procedure. just sit tight.
Oh a recommendation as well is while the cluster is out you may want to buy the led lights for the gauge. They are right under the gauge cluster circuit board. I believe there are 31 bulbs on the cluster. I ordered 30 - T5 leds, (5050 SMD type[tri-chip] made by Jtechnow on amazon.com).
You can also use T5 - 3258 leds(medium light output) also. As long as they are T5.
And after they are installed and the cluster is set back into the dash, DO NOT screw the cluster down yet! Turn the key to on and see which leds light up. For the ones that don't light up they are just installed backwards. You must twist and lift them out, twist the led/lexus bulb socket 180 degrees, and place back into the cluster. Keep doing this until all of your bulbs work. Make sure to turn on the cruise control, ECT, Overdrive?,high beams and headlight buttons/switches to assist you in checking if you installed the Leds in the correct direction/polarity.
-Also use a factory Toyota bulb for the "Low Fuel light". Do not use an led (T5, etc). When you run into a low fuel situation, the T5 will turn on later on due to how it operates. Versus the stock gauge bulb, which will turn on immediately once you run into a low fuel situation.
That's some good info there. I see you named a few electronic stores. My recommendation is that you buy your capacitors from anyone but digikey. They don't have bad products, well who am I kidding, yes there products can suck from time to time. Don't know if it's them or the part manufacture or the process of shipping everything. The reason I know this is, I put there parts in the circuit boards I make at work. Although we did stop using them for a while we are going to go back to them, simply for the volume they have. Right now no other company can keep up with our demand. Anyway I am going to source out some capacitors tomorrow.
No problem guys. I just went to a local electronics store (Orvac, Rvac or even last resort is radio shack), took it apart, and categorized the capacitance values and voltages that were on the circuit board. I then looked for electrolytic capacitors of the same values on the board, but with higher voltage ratings.
The theory behind seeking a higher voltage rating than what I specified above is that the internal materials and design can handle more than what we will throw at it possibly allowing the parts to last longer than one of the same voltage rating as the stock capacitor.
The store I went to charged me about $1 per capacitor. You can get the capacitors from www.digikey.com for a whole lot less, but shipping may make it equal the same price.
Some may want to go all out to the extreme and buy tantalum capacitors, but I think that is overkill. I just bought electrolytic capacitors with a higher voltage rating than what was on the board. I think you will be fine in this instance. I will post in a bit the removal procedure. just sit tight.
Oh a recommendation as well is while the cluster is out you may want to buy the led lights for the gauge. They are right under the gauge cluster circuit board. I believe there are 31 bulbs on the cluster. I ordered 30 - T5 leds, (5050 SMD type[tri-chip] made by Jtechnow on amazon.com).
You can also use T5 - 3258 leds(medium light output) also. As long as they are T5.
And after they are installed and the cluster is set back into the dash, DO NOT screw the cluster down yet! Turn the key to on and see which leds light up. For the ones that don't light up they are just installed backwards. You must twist and lift them out, twist the led/lexus bulb socket 180 degrees, and place back into the cluster. Keep doing this until all of your bulbs work. Make sure to turn on the cruise control, ECT, Overdrive?,high beams and headlight buttons/switches to assist you in checking if you installed the Leds in the correct direction/polarity.
Thanks for all of this great info!! Just wondering if you can post some pics of your gauge cluster after you replaced all of the bulbs? After you replaced all of the LED bulbs are you still able to control thr brightness of the cluster with the dimmer ****? Are the T5 the same base as the 194 bulbs?
Ok thanks for the info! Yes I would love to see some pics. I just wanted to make sure that they were not too bright but as long as the dimmer function stil works then it should be fine. Also what color did you go with. I am thinking white or red.
I went with plain white. I can see some saying that these are too bright. In that case then I would recommend the T5 - 3258 leds(medium light output) vs the T5 leds,-5050 SMD type[tri-chip high output] which I purchased and used.
not for me..I love them that way (I chose some of the brightest). But for some it may be too bright.
Here is a pic of my dash in the daytime.
1994 GS300 gauge bulbs replaced with T5-5050 SMD led [the 5050 are high output, tri-chip leds]. The T5-3258 SMD are medium output, but still a bit brighter then stock when turned to max brightness.
I forgot that I thought to take a picture of the back of the cluster a while ago. The different colors of plastic bulb sockets(black, green, blue) helps to denote which lighting segment group of the cluster that bulb is a part of.
Picture of the rear jzs147 GS300 bulb circuit sheet/board. Also speedometer and rpm circuit boards are the darker green square like shaped boards in the pic.
This a picture taken of the GS300 gauge cluster with T5-5050 SMD leds at night. The gauge brightness is set at full in this picture also. The needles are a custom DIY setup I referenced to here: https://www.clublexus.com/forums/gs-...lp-please.html
Yes I think all but maybe 2 or 3 (I ran out of T5 leds).
I would strongly advise to keep a functional stock bulb type where fuel gauge light is. As soon as your fuel level starts to go low there will be a slight voltage output to this bulb that will get higher (until the voltage increase reaches steady state) as the fuel gets even lower and lower.
The stock bulb will light dimly at first then increase its brightness following the voltage increase.
Whereas, the SMD LED will be off until the Forward voltage (instant-on voltage) is reached. Once it reaches the Forward voltage, then it will switch to being on. The range dimness to full bright is not there like in the stock "gas filled" bulb.
I need to go back into my cluster and change my low level light out myself. I almost found this out the hard way....my light didn't come on.
I installed the new T5 bulbs that you recommend and for the most part it looks great but it seems as if the cluster isn't completely lit. It seems like the bulbs produce "hot spots" or the viewing range isn't wide enough? Did you notice anything like that?
11-08-14, 12:53 AM
Fix: peridically freezing speedometer & Fuel gauge reading below actual fuel level fi
