I was jump starting my car and put the cables backward on my car and now the car went completely dead I checked a bunch of fuses changed a couple that were bad but there is still one fuse out it's the alt 120 a the car is now starting but won't stay on the head lights and the interior lights work but the dash and radio don't will the fuse that I mentioned was still out fix the rest of these problems

 

Uhm, what?

 

yeah bro it sounds like you fried your ecu...

 

This has happened to others and invariably a couple relays and/or fuses are toasted. Re-check all the fuses and relay.

These threads:
https://www.clublexus.com/forums/ls-...lay-ls400.html

https://www.clublexus.com/forums/per...ator-fuse.html

 

I don't think so. The ECU seldom fails because there is a protection circuit against the reversed voltage and the surge voltage in it. As long as you use the correct fuse, the ECU is mostly protected against the reversed voltage.

Other than the 120 ALT fuse, there are some more fuses blown when you reversed the cable. So check carefully other fuses.

I need to add that sometimes diodes in the alternator partially fail. This can't be confirmed quickly because most of the symptom is the slow leak. It would be the best to check the leakage current to the alternator's B terminal. It should be less than 3 mA.

 

The main power distribution on all cars is protected with either fuses or fusible links.

For obvious reasons, blown fuses are easier to deal with than melted fusible links.

 

Unless it's pitch black outside (and you don't have any means of lighting), how can anyone "accidentally" get the 2 battery posts mixed up?

 

Wow. Kick the guy when he's down why don't ya. (It's been a year so maybe he's not still down) Accidents happen, to everyone. That's why RA40 posted those links, cuz ALOT of people have done it. I'm sure you too have done something "accidentally" in your life, maybe not this, but something. We all have. 😉

 

SURPRISE, I didnt post that... my new leaf is working..... would you believe this? I've never crossed the cables or run out of gas..or only had one key,...

have ran out of money tho...

 

Most terminals are easy to see when colored. Some cars they aren't as easy to see and depending on battery type-configuration, the neg and positive can be at different sides. If the covers are gone and the accumulation of road grit smears over the + - markers, it can be a bit challenging. It happens and the engineers have designed enough protection for those moments. People have also put the wrong fluids into any number of other fluid reservoirs under the hood. Tranny fluid in brake, brake in tranny, you can mix any combo of them.

I like that shot Billy! That was when one can reach into an engine bay and have room in most cases to get parts in and out. Could see the ground when looking down through the engine bay too.

 

I am so glad I retired in 1996, I had no idea things would get so tough after that....made me look smart, but it was just LUCK..

 

🤣
The old days were nice and easy, back when you can open a hood and see the bolts where you had to put a wrench.
Yea things sure have changed in the past 25 years, but hell, look how they've changed in 3 months.