ShadyBeing

Had to switch to my SC today as my daily since my Supra's 7M seized this morning, didn't realize how much of a bucket this car is till I drove it home.

Speedo and Tacho don't work, temp and fuel gauges do.
Radio is dead.
Turning signals are static. Left hand signals literally just stay lit when I turn them on, outside and on the dash indicator, right side the front stays on, the rear flashes once and die, never an indication of it on the dash.
The clock is just weird, the minutes change almost at a 1 second interval but not quite, the hour never does unless you do it manually.

I think that's about it for strictly electrical issues, for a while it was showing an oil light despite me just filling it with oil but that went away.

Wonder if there's just a bunch of blown fuses or whats up. It would be great if these are all related but I doubt it.

The AC works but the display is like half way gone, which I think is a physical defect not electrical.

KahnBB6

iTrader: (5)

I'm sorry to hear about your MKIII Supra's 7M seizing! Hope that car can be nursed back to health and get on the road again.


With your SC they are not all related issues. It is remotely possible that a couple of them could be but it's likely they're all just common long term issues.

What is the mileage on your SC? And is it an SC300 or SC400? Model year?

Have you checked the health of your alternator? Be sure its voltage regulator is in good working order. And definitely check all of your smaller fuses under the hood and under the driver's side kick panel that don't have a big bolt through the middle of their socketed prongs.

--Speedo and tach: they can eventually stick after 20++ years and will require servicing to restore them. Contact Tanin Auto Electronix for dash cluster service.

--Radio: check the radio fuses. Does the head unit turn on at all? It could be that the PWR/VOL **** is no longer responding due to an issue there but that's rare. Worst case the factory head unit may have burned out electrically but they tend to last and last. It's more likely there is some other issue preventing it from powering on. If you get head unit power but no sound it could be an issue with the factory amplifier. If at any point it seems like replacement of one or both of these compnonents is the best option, look up Raine's DIY threads regarding the installation of an aftermarket head unit and alternatively his thread detailing how you can continue to use a good working factory amplifier with an aftermarket stereo.

--The turn signal relay(s) may have an issue. Alternatively an issue within the clock spring on the steering wheel... but if there is no flashing at all it would seem to be the relay that makes that indicator and the outside lamps blink on and off that has an issue. That inconsistent flashing strongly points to this.

--The clock is an odd one but IIRC I have heard of some issue with this before. I can't comment from experience with that. Tanin Auto may be able to address this.

--The A/C controller's LCD display going bad visually (but while the unit is still working fine) is another very common issue with SC's. Another job for Tanin Auto to fix by sending in the A/C controller for repair.

As far as basic drivetrain operation however is the SC driving fine despite these issues? No drive-ability issues?

ShadyBeing

Yeah it drives perfect. Its at 102k and its an auto SC300

I was hoping the issues were related but now that you listed how most of them gets fixed I guess it'll just take time to individually work on each one

ShadyBeing

Also just looked up Tanin, they're kinda far and too expensive, $199 to fix a cluster on my $250 car seems like a dumb move, so I will probably have to do it myself, which is gonna suck but hey whatever works best

KahnBB6

iTrader: (5)

To date they're the only outfit that seems to get cluster lighting restoration and gauge restoration right on SC's and other 90's Lexus vehicles. They're worth it if you want it done right. I've used them for several ECU repairs and will soon be sending in my SC dash cluster to them for gauge repairs. Yes you have to pack your electronics well when you send them off to them and wait a bit (unless you pay for rush service) to get them back but those folks are extremely thorough with their repair and upgrade work.

Although you could always try to source out a known working speedo and tach gauges. You'd want to be very, very meticulous and careful when dismantling the cluster and reassembling it. I've replaced the fuel gauge once with one I bought new from Lexus some nine years ago and that alone was an involved process.

SC's are pretty rock solid cars but like any old car they'll have an issue or two given enough years on them. Just because a good deal was had on an SC for $250 does not make it a car befitting of only up to $250 in repair costs. It's an old Lexus but was originally (adjusted for inflation) like a $63k USD (in 2018 money) car when new. With such low mileage (102k!!) and good mechanical running other than the few very common SC issues to fix I think you got an incredible deal! That car will serve you well for a long time to come. Cosmetically inside and out it's likely in pretty good shape as well with such low mileage on the odometer.

If it were any other issue other than the cluster I might have someone else to alternatively recommend but in the specific case of SC gauge clusters I really don't recommend anyone else.

Again, if you have no lighting issues and just want to address the gauges you may be able to find good ones on ebay to replace in there. Lexus might have them in stock still as well but for that money it makes more sense to send the cluster off to Tanin to have the malfunctioning parts rebuilt anyway. And I'll be honest, personally I could try doing it myself with my own gauge cluster but how do I really know if the used gauges I'm buying off ebay are in 100% good condition? I'm not going to buy the parts from Lexus given their asking price for a brand new SC tachometer or speedometer.

It's just more foolproof to send the cluster in for repairs with an outfit who know what they are doing. And I say this as someone who is not afraid of getting his hands into building/soldering an entire engine swap harness and other custom vehicle electrical work. I'll do plenty of DIY repairs and work on my own SC. The gauge cluster service just isn't one that makes sense to when a pro outfit already does it all day long and tests all customer orders on shop cars before releasing them, IMO.

And if they still exist, avoid a company called "Lextech Lighting". They are well documented on the forums with many negative experiences from Lexus owners who sent clusters into them for repair only to have major issues afterward.

ShadyBeing

Seats are screwed and exterior needs top side painted its not a looker that's why it was cheap

I'll look more in to it but so far I may look somewhere local, Orlando has a ton of JDM and Toyota/Lexus shops