mrbrandon

Hello gentlemen, I have a '94 Lexus SC400 with 248k miles and have owned it for seven years. Outside of your typical parts (alternator, radiator, power steering) going bad, I've never had a problem getting the car to start.

I just returned from a week long vacation to discover I can't start the car. When I put the key in, the door chime doesn't stop regardless of what position I turn the key to. When turned to ON, nothing lights up on the dash and I hear none of the typical fuel pump/preparation noises the car is supposed to make. These are all a brand new/never encountered symptoms.

In addition, some of my electrical components have stopped working. Everything power, Stereo, CCU and Dashboard don't work. The Door Chime, Horn, Interior Lights do work. The battery and alternator are both less than a year old and the battery tests out as good.

I've spent the past couple days researching what could be wrong and followed some suggestions. I tried using a valet key and that made no difference. I checked the 7.5amp fuse #4 in the driver panel which is responsible for the starting system and it was OK. Made sure the car was in gear, attempted a jump start...nothing.

Any ideas of what it could be? I'd love to avoid towing it to the stealership if I can and keep it on the road to the quarter million mile club...

mecheng10

that sounds like a dead battery.
but if you said you tried to jump start it? When you did that did you get any electronics back?
also check your battery terminals. make sure they aren't lose.

take your battery to a parts store and get it tested?

SC & LS 40

I let my 92 SC400 sit for a couple of weeks and had the same problem when I tried to start it up last weekend.

Tried jumping with my truck. Nothing. Let it sit with the cables connected for about 1/2 hour. Nothing.

Put the battery on a charger overnight, fired right up. Other than resetting the seats programing, clock and radio pre-sets, no problems since then.

Second vote for battery check, plus a full charge, before looking for more complicated causes.

Good luck!

mecheng10

these cars are known to kill batteries...
even stock. they seem to like to draw no matter what you do. unless you disconnect the battery

PJSC300

It sounds like the battery. I would suggest taking it to autozone since they will charge it free of charge.

SC400slide

iTrader: (11)

Trickle charge the battery overnight. You'll be good to go in the morning.

mrbrandon

First off, thanks for all the great responses everyone. You're all a great help!

mecheng10, I need to add that when we were in the process of jumping it my dad mixed up the polarities for about ten seconds. Once he had it right, we left the car there for about 5-10 minutes before returning to it. While I was revving the engine he discovered the car's current behavior of no dash lights, radio, etc. even with everything connected.

I grabbed the battery to bring home earlier this week when I discovered something: the ALT fuse and ALT SENCING fuses were blown. I went ahead and ordered those and brought the battery back with me to charge per the suggestions here. The battery was indeed dead and fully charged up to 100% according to the readouts on my charger.

When I replaced the fuses and connected the fully charged battery today, smoke immediately began rising from near the alternator. I was able to disconnect the battery without losing a fuse or catching anything on fire. Once disconnected, my Uncle said it smelled like an electrical burn where the smoke came from. He thinks its a bad wire connecting to the alternator.

Either way I'm gonna need to have it towed home so I can get a look under the car.

mrbrandon

I think I've discovered the root of the problem. The alternator is blown and the power coupler end is unrecognizable. I've attached pictures below.

Is there any way I can get a new Alternator Power Coupler End?

mecheng10

oh wow.
never seen that happen before.
maybe get with kurt from Elmhurst and see if you can order the plug
or find a sc going to a scrap yard and get one.

mrbrandon

How do I get in touch w/Kurt?

Lexus wants $140 for the alternator cable. It's a two way foot long and plugs into the alternator as well as what I assume is the wire harness. There is apparently only one of these in the country right now and they're overnighting it here.

mecheng10

he is on supraforums.
or you could try aliga (he is on here and is always partin gout scs)
I wouldn't pay 140 bucks for that. its some wire and a plug.

mrbrandon

Good news! I was able to get around buying the Lexus cable.

I replaced the alternator with a NAPA one and found an "Alternator Repair Plug Harness Connector" on eBay ( http://www.ebay.com/itm/181305348944...84.m1497.l2649 ). I spliced together the wires, covered it in electrical grease, put some tubing on and melted it, covered it in electrical tape and it was all systems go. Car started on its first try but I now have that dreaded AIR BAG light issue where it stays on all the time. The car had it when I got it back in 2007 and I haven't had a chance to get rid of it yet.

Thanks for all the help everyone!