Ls400 Fuel Guage

[dellstar]

LS400 '93 83,000 miles I am second owner fuel guage is starting to misbehave registers zero for a long while after starting then creeps to halfway I just cant trust it so I fill up whenever I can making me very nervous previous owner said it was a fuse! I dont think so - probably an electrical fault or even worse! Ayone else experience untrustworthy guage problems?

[GreyBeard]

i've a 1990 LS400 and mine is a bit eratic, so i've been reading all the posts and links in LOC. somewhere i read that when the power supply chip starts to fail in the instrument cluster or climate control display, not only do the instrument needles start to not light up, or the climate control screen goes black, but it also affects the performance of the guages because they are not being fed a consistent voltage. have you got probs with your displays?

[ColinBarber]

I've known voltage regulators cause this type of problem on other vehicles too.

[obergc]

Many people claim to have repaired a slow or erratic fuel gage by replacing a couple of electrolytic capacitors on the power supply board in the instrument cluster. One gent said that he replaced capacitors C142 and C147 on the larger of the two circuit boards in the instrument cluster and it completely cured the problems that he was having with his fuel gage. Word of warning, if you remove your instrument cluster for repair, make sure you disconnect the Battery before removing the cluster or you will have a constant airbag warning light when you reconnect the instrument cluster.

Curt