93 Ls400 Dead After Wrong Polarity Boost

[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.

[VMF]

there is a big possibility that ur ecu might be fried as well but you should check all the fuses in the engine compartment first. ls400 has lots of electronics so this spike might be fatal to a lot of things. but first things firsty check all the fuses.

[Lexls]

Yup, check all the fuses first. Then check the relays and maybe reset them if the fuses are all good. I doubt a little mistake like this would totally kill your car. Let us know what happens...I've never heard this one before

[dilligaff82]

I had the same thing happen to mine. Check the fusible links right next to the battery, and the white one (130amp) will be blown. Maybe a couple under the dash too.

[gullwing]

UPDATE

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.

[SKperformance]

where is the main relay?

[gullwing]

where is the main relay?

←

It is in the fusebox ( the one in the engine compartment , next to the battery ).

Anyways, my car is fixed now ,It was the main engine relay and the ground cable for the fusebox !

Thanks to ALL !