I'm Trishanna and I just inherited a 2000 Buick LeSabre Limited. I need some feedback and ideas from some experienced owners or mechanics on this beauty. It has some quirks that I'm trying to figure out what is going on. I am pretty savy but this car has me baffled.
Quirk #1 = I noticed a couple days ago that the car has no back up lights, license plate lights, or lights on the trunk. I first checked bulbs and replaced if needed. Nothing new. I next checked fuses both in engine compartment and under back seat. All looked good. No change. Next I took a tester to the plug inside the trunk. Positive for power. Then checked the individual sockets. Positive for power except the reverse lights. Placed vehicle in reverse, still no change. Replaced bulbs and still nothing. Help!

Quirk #2 = The car inside temp is always hot on driver side and cold on passenger side. Figured it may be a door in the system being stuck open or closed. All gauges read normal so not likely a thermostat issue. Boy does that Auto temp system blow especially to whomever is in the passenger seat.

Quirk #3 = The heated seat on the driver side lights up on the switch but doesn't warm the seat. Any ideas?

I pulled and checked every mini or maxi fuse. Don't know if it'* a relay that'* bad or something else for all of these issues. The previous owner was like a great grandma to me, and she always had work done by an authorized Buick dealership. Within the last couple of years, the car had a new fuel tank put in, rewiring of the back end due to rodents chewing things up, significant break job done, new battery cause she kept leaving her lights on. Any help would be much appreciated.

Problem 1 I bet is a bad ground at the rear light harness. Problem 2 Could be a few different things, as you said it could be the temp door actuators or it could be the heater control unit it'* self, or I have seen the cabin air temp sensor go bad causing similar issues. Problem 3 is most likely the seat heater grid it'* self. When I worked at the Buick dealer I replaced quite a few of them. A good upholstery shop can most likely replace it.

#1 all share ground G401, so could be that or if they recently worked on it could be loose or a chewed spot that they missed

Thanks for the info. I'll try to find that.it just seems wierd that when tested all work except rev light. But when bulbs are placed in they don't.

Thanks so much for your response. I'll check out all of these and let you all know if it works.

thats how you know its a ground

If you get all the other lights working and the reverse lights still don't work it could be the reverse light relay which is located in the fuse panel under the back seat.

Hey all, it'* been a while but I wanted to let you all know that I fixed the light issue. It was a bad ground in the trunk near the passenger side hinge that they didn't have taped up real good. That is all fixed. The other issues posted earlier I am just dealing with at the moment.

I have a bigger issue. Please help. My car is running horrible. Initially I thought it was a clogged fuel filter. Nope. Replaced it anyway. Ran Seafoam through for any moisture. Nope. Still bad. Found out I am not getting power to #3/#6 Ignition coil. I replaced it thinking it was the issue. Nope. Tested wires and they are good, new plugs, the wiring to and the plate that the coils sit on look fine. Runs like crud and am getting a random misfire on the OBD2. Any ideas?

By the way. I did also check my fuel pressure and it is 50psi at ignition turn on and drops to 44psi at idle which is within norm range according to what I've read.

its likely the ICM, if the other ones work. does it look like there is any corrosion on the tabs?