How do i get break light on dash to go off? and how do i disconnect the onstar ? mine has been turning on and off acting funny like there is a short in it?

check the fuze relay

I 'll attempt. 3 places I have found onstar on GM vehicles. Older cars, you have to pull the dash to access them, Not yours. Next is under the dash in front of the center console. Still a pain to access, just to even unplug. Next is in the trunk, on the drivers side behind the carpet. Easy to recognize. One or two plugs and an antenna wire. I haven't eve replaced one. But disconnected many because they will kill data lines/ other computers. Just shorted out.

Sounds like bad grounds Grounds are at the steering column, under the dash, and behind the kick/side panels on both sides or the car.

for nothing on the dash to work ,it indicates that a ground wire is missing, broken or the ground point is rusted
Could be the BCM unit so run the fault codes as well

you need to change your fuses

You have an ABS light on !!

Why wouldn't you have had it checked for fault codes
& had the problems resolved?

We have only had those dash lights & codes for
over 30 years, so no reason not to know the drill

No

But the ABS Braking System --can do funny things-- if you
have a light lite on dash

The transaxle may have failed

It is about due for a rebuild after 13 years

Sounds like a loose connection to the starter, on the battery or maybe the battery is so far junk that its acting funny. Try a new battery. Are there any lights on the dash like "SECURITY" or anything like that? Comment back on this if there is.

dont worry all you need to do is just change the 2 sensors found onlong top side of the break peddle. it be cheaper if you could get it from the junkyard from even a mecury contour or mystic, both cars have all the same parts as the cougar , try it i did.

Open the back hatch of your Chevrolet HHR.2

Lift up the floor mat on the bottom of the trunk. You will see your spare tire, jack and OnStar unit. Unscrew the top of the OnStar unit, using a Phillips screwdriver.

Remove the lid from the top of the OnStar unit box; you will see three white plastic cables running from the OnStar box to your vehicle.

Unplug the three cables from the OnStar unit to disconnect them.