Why is my cadillac rear so low

Question edited for clarity and toss in some CAPS.

Digital display, you probably need an auto electrician.

https://www.google.com/search?q=Cadillac+Deville+Concours+display+not+working

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the procedure is fully explained with photos in a work shop manual available from any parts shop

http://www.ehow.com/how_7794388_remove-dash-2000-cadillac-deville.html This will show you how to remove your dash. If you have any more questions please let me know. And please leave good feedback.

change the coolant temperature sensor, if that's not it, look into the head gasket leaking.

was the new alternator a re-manufactured one,(they have been known to be faulty)

Do you hear your compressor running? It may be that it is getting tired and ready to burn out on you. I replaced the compressor twice on my Deville before I found that there were so many holes and nicks in the air bags and it was going to cost me almost $1500 to fix the whole system. I went online and found Strutmasters. I got a non air conversion kit for my car and love it. Saved me money and headache.

check for bad wire or a rub...also check your connection between your plug and light

on my 99 devillle concours cold air blows from left and back vents but hot air blows from right vents

looked it up online and looks like it's on the front of the water pump in a thing called the coolant inlet housing. one end of it looks something like the letter y and the other end, where the thermostat is round. hope that helps