vman1100

Finally - This is a problem I have been after for quite a while now. The instrument needles on the gauge cluster have been blacking out and coming back on for months now. I had the needles replaced but no help. I had become expert at pulling the instrument cluster and trying different things. A local car wash guy noticed what was happening one day and suggested that I check near the shift unit. This is a 1993 SC300 - 5 Speed. Sure enough, I pulled the shifter cover and found an electrical cable trunk line runs along the top of the transmission cover into the main dash unit. This trunk cable was lodged between the rows of the rubber shifter cover on the transmission cover. It would move everytiem the shift lever moved. I relocated theis cable to be below the rubber cover ans sitting solidly on the transmission cover where any shifter movement will not affect the cable. Lo and behold - the problem went away. This was simply amazing. This problem had kept me from really enjoying this car for a long, long time. Now I am so happy I need to share this info with anyone else who may be experiencing the same problem. Now I can truly experience just how good this car is. . . If this helps even one other driver, then I would be elated. Better late than never...

I wouldn't send them to lex#$%@ lighting. They do not do what they say they will and basically they grab the next cluster off the pile and slap new needles in. Therein lies the problem. They promised me that everything would be working and calibrated before being sent out. My gas guage has never worked correctly since and my speedometer is off by 6 mph. - it understatesmy speed, thereby putting me at risk. I have tried every fix lex#$%@ has quipped to me and finally they just stopped answering my emails. Nice way to do business - huh ? DO NOT SEND YOUR INSTRUEMNT CLUSTER TO lex#%$@ lighting. I am sorry I ever heard of them. If it was up to me, I would have evry reference to them banned from this site... Vince...

I havew had experience with Lextech Lighting, and I cannot recommend then to anyone until they make things right foir me. Right now, they will not answer my eamails asking for help. Before the sale they promise the world and after the sale they 'don't know you', because 'they are way too busy to do the work accurately'. They' take a cluster off the pile' pull the needles, stick new ones on (sometimes) and on to the next'. All their talk of carefully calibrating and checking each unit is Bull$%&*. They live in the eworld, yet they can barely express themselves thru emails. Can you se4nse that I am a little unhappy with them ? vman1100... java script:emoticon('', 'smid_16')

Hey - I just found your posting on the site (from June 50).. I can't help but reply, I am basically having the same problem. The exception being, that mine stated acting up after the professionals at le.t.ch lighting did a superb(ha ha) job of fixing my cluster needles. Before they got my money, they promised me the world. Since then, they will no longer answer my emails regarding my ongoing situation. So much for that outfit. Right now, my recomendation would be for people to spend the money and send their insturment clusters to the dealer for work. At least, they shouls stand behind their work. the other guys won't. Anyway, I also have posted in the forum and asked for help regarding this issue but have gotten no replies,. I can't believe that there isn't someone out there in this forum who would have a technical manual and at least be able to give us some direction regarding this fuel gauge. The link above to the repair./clean of the sending unit is for a SC400 which is not like the SC300 at all. I called my local dealer today and asked him if he would test the resistence on my old sending unit if I brought it in. He very rudely told me that they would not. I mean I didn't ask him to do it for free, I just asked him if he would speck it for me. Nice guys huh? I guess its tough to make money at $125.00 hr.. Anyway, you can easily remove your sending unit from the gas tank and put a multimeter on it to see if it is sending different voltages out when you menually move the float arm. If the voltage doesn't vary, then your sending unit is bad. Cost $130.00 approx from dealer. You install. I still believe that there is a way to calibrate the fuel gauge itself, but no-one is willing to give it up. Why - I don't know. I do know that Lextech lighting will not let me post and ask questions on their forum even though I am a customer in good standing. I guess they only want you post and say wow 'look at all the pretty lights'. . . Anyway, let me know how you make out... vman1100... java script:emoticon('', 'smid_16')

I take it you might be kind of handy, so if you like you can remove the sending unit unit again and test it with an ohm meter. The float is attached to an arm. That arm is connected to a small elect box. That box is actually a potentiometer. When the tank is full, the arm raises in th tank and moves the contacts in the pot . A full tank would offer low or little resistence, thereby allowing a full signal to send the fuel gauge up to full. As the float or fuel level goes down, the arm moves down and makes the pot offer more elect resistence, thereby sending a smaller signal to the fuel gauge thereby showing a lower fuel level. This is really a very basic construct. If you connect a mutimeter to the sending unit and manually move the float arm you will see the reading on the meter move. If you move the arm and the meter reading doesn't change, then something is not right with the sending unit. I have the opposite problem. My gauge wants to read near full all the time. I have replaced the orig sending unit because it was always sending a full signal, but then I never tested the new unit. I may have to pull the unit again and test the new unit with a meter. I am also trying to find out if the re is any kind of calibration that can be done to the fuel gauge itself. Good Luck . . . Feel free to let me know how you make out. I hope I have been able to help yopu a little... <_<

Here's what I've found with my 93 sc300. Attached to the fuel tank sending unit is a low level fuel indicator sensor. If the actual fuel level in the tank goes below this sensor unit, then the dash light will come on regardless of what the guage is reading. I don't know if you can replace just the sensor unit attached to the sending unit. |If you don't want to see the light on all the time, you can just unplug the unit at the top of the fuel tank sending unit. It is the smallest elect connection at that unit and has only a single wire attached to it. Good luck with that. Right now I am trying to see if I can recalibrate my fuel gauge itself. Feel free to let me know how you make out... Vince... ;)

I have just replaced my fuel tank sending unit at a cost over 120.00. The fuel gauge still continues to want to read as a full tank. It appears that the new sending unit is working better than the old unit, but it still seems inaccurate. Is there any calibration that can be done to the gauge to bring it more in line with the actual fuel level in the tank ?

Any and all Lexus dash lighting needs (repair and customization) can be taken care of here as well. Lexus Lighting Systems ← Hey - I just read your dash lights problem. I just got my instrument cluster back from Lextech Lighting. The price was right($99.00), but their service was less than what was promised. Before I sent the cluster we had several emails where they PROMISED in writing that everything would be 100% correct before it was returned to me. Well, I got the cluster back, the temp gauge needle was just floating around within the cluster. After I figured out how to fix it, they told what to do. Then one of the backlight bulbs was not working. Their answer 'smack the top of the dashboard'. I questioned the accuracy of the new fuel gauge needle and they told me - 'pull it off and put it where it should be' - (This was their very careful calibration they talk about). If you can get the needles, all you have to do is take out 6 screws from the back of the instrument cluster, pull the old needles off and place the new needles on the original posts. - This is not rocket science. Apparently LexTech is Way Too Busy to do any type of calibration (although they would lead you to believe that they check and calibrate every unit that they work on) - My opinion of LexTech - you get what you pay for. They are a small parts replacement shop - and their customer service is MARGINAL. . .

:cries: "Roger that" LLS - I appreciate your time and guidance. I love the car, but this is driving me nuts. If a used cluster is too expensive, then I will just have to live with it. We shall see what we shall see. . . Regards Vince. . . :(

Hey Gang - I just got my instrument cluster back from LexTech - they replaced all 4 instrument needles. The Problem I had before I sent the unit is still with me. When I start the engine, sometimes the needles will light up and sometimes they won't. Sometimes when they are on, while I am sitting in the garage with the engine idling the needles will go out when I move the shift lever. Sometimes they will work steady for a while and they they will just quit. It seems real odd and the backlights stay on... I have cleaned and replaced the ground connections, and both battery connections, checked the alternator, had LexTech replace the needles and still the problem persists. So far Lextech has not found the problem... Any ideas ? Vince...

Well gang, we will try this again. It has been more than 2 weeks now, and the electrical engine cut out problem seems to have gone away. Here is the final work done. It had been indicated by Sergio and others (myself included) that the problem was in the negative or ground side of the electrical circuitry. Apparently that is the case. I had cleaned the battery terminals before and the electrical connections at the battery and behind the battery at the body grounding spot. What everyone seemed to be saying, but that I did not pick up on, is that when you inspect the ground wire carefully, you can see that there are a couple of other places where the ground wire is connected to end terminals by crimping. Apparently what needed to be done, was to tighten these crimped connections. I managed to squeeze some electrical connection grease onto the connections, which would help to dissolve some light corrosion where the ground wire is crimped on to the end connection. Then I used my TRUSTY Vice-Grip pliers and put as much pressure on the wire connections as I possibly could. There were three connections that I could reach near the battery itself. I could not reach the connection at the starter - But apparently the FIX is in place. So, it was a ground problem - just not very easy to find. I had scheduled a 2 hour trouble shooting session at my local Lexus Dealer (2x$95.00 = $180.00) plus parts. He told me he would be looking at the alternator ($339.00 + tax). I strongly suspect that he has seen this problem before and if I hadn't stuck with it he would have happily taken me for well over $500.00. I know he has to pay the rent, But so do I. . . Thanks to all of you for all of your assistance. . . Vince. . .

Darn . . . The problem is still with me. The service manager at Lexus is suggesting a possible failing alternator. But, he admits that an intermittent problem is difficult to diagnose and without knowing for sure, we would be just shooting darts. I for one do not feel like playing a $600.00 game of darts. Anybody got any more ideas. . .

Here's an update on the electrical problem. I again cleaned the negative terminal and cable ends. Retightened and this time did NOT apply a light coating of grease to the connection. The problem has NOT reappeared. Keep it clean, keep it tight and NO grease. Appears to work for me. . . Thanks everyone for your input. Vince

Corvette - great car - drive anywhere any time day or night - just to drive. Jaguar XKE V-12 - fabulous engine - typical British elec problems - ruined everything Triumph TR 3 - drove it in college - fun car - drive it for an hour, fix it for 2... VW Scirocco - really fun car - very fast for a 4 banger - handled great .. . 89 Acura Legend Coupe 5 speed - Best Car I ever owned . . . 2000 Maxima SE - very fast - very cushy ride - might consider another one... Toyota 4 Runner SR5 - just a great vehicle. Hate to get rid of it, because they don't make a manual transmission any more. Next car - Infinity (either coupe or maybe the G35)... (yeah - right after I get done paying for my son's college education.) That's OK, because he's a good kid and right now he's driving the 93 SC300 5speed Black. (I tried for quite a while to find a 94 Acura Legend Coupe 6 speed for him - but couldn't do it.) That's how we wound up with the Lexus. My feelinf is that it is a good car if we can only get past this darn electrical problem... There were others , but that's all for now. . .javascript:emoticon(' ') smilie

hi u doin man my name is sergio and i think i can help u. A little about me, Im 20 years old and I have my own installation shop and we major in electrical issues. Ok it sounds to me like u have a ground issue. It wont be at the batt or ing. switch. i had the same issue with a 96 escort. what we found after a 30 min drive the car would do the same thing. the frame ground [body gnd.] wire was bad and it would heat and seperate inside the insulation of the wire. we ran a wire [ 10awg or bigger] from the neg. side of the battery to the actual frame of the car itself. we attached it with sanding a little paint from the fender and using 4 self-tapping screws. this wire may but maynot show indication of melting. the insulation of that wire may be a little bubbled but may not show it. the reason why i think this is ur problem is because u loose power to the car and it resets itself. i dont think but it is possible that the pos. side of the wiring could be bad too check all connections and make sure that nothing is loose. if u still need help u can call me @ 216-376-4515 ← Sergio - Thanks for your info. Sounds to me like you are talking about a 'grounding kit' that I see posted every once in a while. The wires both look good at the Battery end of the connections, but I haven't been able to get under the car to drop the shell and check things out down below. I will also check on the back end of the positive cable to make sure it is clean and tight. Right now after I have cleaned (again) the ground battery connection and removed the protective grease coating I had applied over the top of it, the problem has not reappeared. It is intermittent and I do not have any confidence that the problem has been corrected. I just need a dry day when the temperature is above 8 degrees so I can get under the car and try your suggestions. - I just hate electrical problems with cars. . .