LS400 - Complete Electrical Failure

[jjmancini]

I have a 1990 LS400 here is the problem I am having, and would LOVE any ideas.

PROBLEM:
When I start the car up, nothing that is electrical works, yet the car still runs. Brake lights, dashboard, radio, powersteering?, windows, gas latch, remote key, everything electrical does not work. Brand new battery. Any ideas? I have checked fuses, but there is no one master fuse.

BRIEF HISTORY:
This car ran just fine 6 months ago. Then the car sat outside for about 5 months. When i went to start the car, the engine would not turn over. I went to jump it, bu battery would not hold a charge. Took it to autozone they said battery was grounded, so I got a new one, installed, and the vehicle started up just fine, and runs fine, but nothing electrical works.

Any ideas would be GREATLY appreciated!
Thanks!

 

[Lextreme II]

Alternator might be bad.

 

[rms]

I had a similar situation.
Check the main 120amp bolt in fuse at the main fuse box under hood.
That was my problem. Engine would run - nothing else would work.

 

[adarmo]

Had similar on my BMW when batt went flat.

On that, remove battery lead, wait 5 mins reconnect.

Everything burst into life.

 

[jjmancini]

I looked everywhere I thought plausible, but I was unable to find it. Where do I find the 120 amp bolt in fuse? Which one is it?

 

[spf_lexus]

Impossible to tell over the internet but based on your details I would yank the alternator out 1st and check it. 1990-1994 LS400 alternators commonly go out from alternator fluid leaking into the alternator from above. This was a major problem for early LS's and SC's.

Unless you dropped the new battery, these things last 4-7years. I would rule battery out for now.

Check all your major grounds too.

 

[Lextreme II]

I looked everywhere I thought plausible, but I was unable to find it. Where do I find the 120 amp bolt in fuse? Which one is it?

120 amps should be in here. See pic. Did u test the alternator yet?

 

[jjmancini]

Yep! That was it. The white 120 amp fuseible link was blown. Ordered a new one that should be in tomorrow. Thanks SO much for the help. I'll keep you posted!

 

[a.Lpha]

Just a heads up now though, check your alternator (even though it's not the issue) and power steering pump. I had mine explode all over my alternator and kill it

 

[dsabc2867]

almost the same

i kinda have the same problem with my 92 ls400. the battery is new but my radio and steering control button do not work any idea on what it might be. all fuses have been checked and they are all good.