Gullwing

Hi guys. I been having problems starting my car in the cold (93 LS400) but It would always start and run after a boost ( jump-start) . Today, I was supposed to go get a new battery and have my alternator checked , so I called my friend to give me a boost like he's done before and I reversed the polarity on the battery by mistake. ( I know I know...what a dumb mistake, but i didnt have my coffee and cigarette yet ! ). Anyways, after that happened , the car went totally dead, like there is no power at all , not even interior lights. WHat could cause this ? Is there a main engine fuse on these cars ? Or maybe the main engine relay is the one that fried ?

What other damage should I expect other than blown fuses...you think my ecu could be fried as well ?

Please help guys im really lost here. Thanks.

Spottty

I dont have a Lexus (Yet, picking mine up next week) but I'm pretty sure every car has a main fuse in the fuse block under the hood. It will probly be a big mother, like 100 or something. Just check them all.

I did this to a Ford Escort once and it was just the fuse, no other damage. I think for something as advanced as a Lexus they probly thought about that and put in a fail safe.

nk1983

theres also a starting fuse..thats in your actual fuse box under your dash. Then theres main fuses under the hood. CHances are you blew more than one. If you replace the main fuse and the key turns and you get lights but it wont start then its your start fuse.

GRAND_LS 4

iTrader: (2)

It's the main fuse, that fuse controls all others. I think its pinkish on the LS under the hood, it will run you whopping $2.15 at AutoZone. (its one of those big ones).

Your lucky this time, consider this a friendly warning from your LS

(my friend that didnt know what a fuse was almost had a heart attack when this happend to his 96LS.)

Gullwing

First, Thank You for the replies, I appreciate it guys !

Here's what happened today: I went to check the fuses that you guys mentioned, but before I even check a single fuse, I open the door and I realise there was power ! So I start the car and I drove it to my mechanic right away. ( I still need to have my alternator checked )

When it got to the shop It went totally dead again ! That's very weird...I'm stumped. Anyways my mechanic told me he played with the main engine relay ( a black relay ) and the power came back intermittently... So just to elminate this possibility I am getting a new main engine relay today and I'll let you know what happens afterwards.

Gullwing

It was the main engine relay and the ground cable for the fusebox ( the one in the engine compartment ).

Thanks to ALL !