1993 Ls400 Dash N Trans Problem

OldShep · February 20, 2011

Hi there just bought myself a 93 ls400 with LPG conversion,it has the usual dash problem and I already have the parts to sort this. I now have another fault that developed after I charged the Battery. On the way home from my parents where Id left the car for a week only to find the Battery flat, everything was running fine until I switched on the lights, immediatley the dash showed the reverse indicator and rear fog light as well. Shortly after this the transmission began to stuggle and I limped home at low speed taking a couple of breaks to let her cool down and tried to check things out. This morning Ive driven the car and as soon as I switch the lights off the car runs fine, theres plenty of trans fliud although it may be a little tired now. Any ideas please ?

ROYT · February 20, 2011

Hi there just bought myself a 93 ls400 with LPG conversion,it has the usual dash problem and I already have the parts to sort this. I now have another fault that developed after I charged the battery. On the way home from my parents where Id left the car for a week only to find the battery flat, everything was running fine until I switched on the lights, immediatley the dash showed the reverse indicator and rear fog light as well. Shortly after this the transmission began to stuggle and I limped home at low speed taking a couple of breaks to let her cool down and tried to check things out. This morning Ive driven the car and as soon as I switch the lights off the car runs fine, theres plenty of trans fliud although it may be a little tired now. Any ideas please ?

There was a popular fault on early LS's caused by a break in the wiring in the LH boot lid hinge.

This caused weird trans and dash problems.

Check this wiring first, before looking elsewhere!

steve2006 · February 20, 2011

Welcome to the LOC

Here you go

http://www.lexls.com/tutorials/lighting/bulbout.html

OldShep · February 26, 2011

thanks for the information Ive had a look, sure about how to best access the wiring and does anyone know what the exact fault is. a mechanic freind suggested its a short on the wiring thats confusing the ECU ? Possibly on the rear fog,reversing light or boot light.

ROYT · February 26, 2011

Look for a break in the wiring in the L/H boot lid hinge.

This will be an internal break, looking at the outside of the wire may not reveal it,

if this is the problem...

steve2006 · February 26, 2011

As RoyT says it may not be obvious by just looking,it is normally the white coloured wire that causes the problem,if you try to stretch the wire it will normally completely break as the inner copper core has already broken.

Release the loom from around the hinge then unwrap the insulation tape to reveal the inner loom,separate the individual wires and look particularly at the white one.

Once you find the break don't just join the 2 ends back together add an extra short piece of suitable wire to provide more slack,retape and then refix back where it was

OldShep · February 27, 2011

thanks for the additional info I feel much more confident in tackling the problem. How difficult is the dash removal as I'll need to remove it soon and get my brother to swap the capacitors?

The-Acre · February 27, 2011

thanks for the additional info I feel much more confident in tackling the problem. How difficult is the dash removal as I'll need to remove it soon and get my brother to swap the capacitors?

removing the dash is easy enough, I did mine in about 15 mins. Just be very careful because there's not much slack on the wires, and remember to pull the plugs and not the wires themselves. I think there's also a minimum amount of time before you start after disconnecting the Battery, check the posts first!