new 90 lsc, orange ground wire fix - problem

[HRLMVII]

hey guys, just got another lsc fromn the junkyard

i did the orange ground wire fix to get the tach working with headlights on, but as soon as i did, the fuel gauge in the instrument cluster stopped working (it went all the way down to past E--it was slightly messed up before- it would say 3/4 when full)
but if i disconnect my new ground wire, the fuel gauge works ok (still with the 3/4 = full part) with headlights off anddies with headlights on.:eek:

also, before the orange wire fix, the dte on the tripminder would always be 439 miles, but now after the fix, it goes between the actuall distance to empty or beeps and says zero...:eek:

if anyone can help it would be great, i hate not knowing how much gas i have left:mad:

i would love to have my instrument cluster, and my tripminder, work the right way, whether or not my lights are on

[Bluegrass]

Go to the tech section of this board and find the articles on cleaning up the Trip Minder.
Once you have done this and there are still issues then look at the rest of the circuit for faults.
In the dash is a small module that drives the Trip Minder and the fuel gauge seperatly.
There can also be a problem back at the tank as well as the fuel level sender function.
Getting a car out of the yard can have any or all these faults and often the reason the car was retired early because no one knows how to fix the faults.
Trick to bringing a car back from the dead is getting a shop manuel and learning about the various functions before trying repairs.
Good luck.