1991 Lexus LS 400 Change Alternator

DON GRIFFIN

MEMBER
1991 LEXUS LS 400
V8
FWD
AUTOMATIC
168,000 MILES

While being driven dash warning lights came on. Then everything went dim and the car stopped.
The car was being driven by my wife. I had the battery cheched and it is good which leads me to believe the alternator is bad. I have changed many alternators over the years but never one mounted on the lower have of the motor. I am inquiring as to how involved this job will be and will it necessitate a lift or will a floor jack work? Is it possible to do it from the top?

1 Reply

KEVINSTOYOTALEXUS

MEMBER
5 POSTS

Hi Don -

I have a 1991 LS400 and have changed the alternator a couple of times, the last time being 2 or 3 years ago. It is not a very difficult job but it is a little tricky. It does come out from the top. First, remove negative battery cable, the plastic ducting and fan belt. Note: draw a diagram of the fan belt/pulleys before removing. You might have to remove the fan, however, I don't remember doing this. Next, remove the 14mm bolts with a long arm ratchet/socket setup to get leverage to loosten the 2 bolts. Next, slide the alternator off the top bolt. It comes out pretty far and you may need to remove the upper radiator hose or move it gently with your hand while pulling on the alternator. Finally, when you have enough clearance, you need to remove the feed wire and rear connector before carefully, as not to bump the radiator, pulling the alternator straight up and out. Remember, it's a tricky job but it's not hard. I completed the whole job every time in no more than 1 hour.

I hope this helps.

- Kevin