Question about Cadillac STS
First check engine
coolant level; if there is too little coolant in the reservoir,
you should be alerted to the possibility that there could be a leak somewhere in
your car's cooling system. Remove the reservoir cap and add coolant to the Full-Cold
line, if a very short time after you refill the coolant reservoir the coolant level
is low, there is a leak in your car's cooling system.
Engine coolant is used to heat the heater core and if the vehicle is low on coolant the heater core will stop working. The heater cannot produce heat due to the lack of heat from the engine coolant. Even if the engine is not over heating the coolant level can still be low.
Nest step, inspect Heater Control Valve that is used to shut off hot coolant from entering the core when the heater is in the off position. A heater control valve can be actuated by either a vacuum line or a cable from the vacuum heater control valve to the heater core. This hose should be warm; if not the heater control valve is stuck and needs to be replaced. After the repair has been made refill the coolant level and recheck system.
Also, keep in mind that Blower Motor (electrical motor) is used to push air through the heater and air conditioner system, if the Blower Motor fails it will not force air through the system. Ground a test light lead to a good ground source, like a metal brace under the dash, seat mount bolt or under hood brace. Turn the key to the on position; check the fuse in the heater or blower motor fuse panel with a test light. Then lightly touch the service port at the top of the fuse on both sides. If the test light illuminates on both sides of the fuse, the fuse is okay and working properly. If the fuse lights the test light on one side it is blown and needs to be replaced.
Finally, if you are unsure of the location of the heater fuse consult a repair manual. If the fuse condition is OK, position the blower speed to the highest setting. Connect the ground end of the test light to a known ground source. Then probe both ground and power feed wires of the fan motor. The test light should illuminate on only one of the wires (fan motor failed). If the test light illuminates on both wires the ground source has shorted. If neither of the wires illuminate the power source is shorted.
Hope this clues helps; keep us updated.
Posted on Sep 14, 2011
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Tips for a great answer:
Aug 05, 2016 | Cars & Trucks
Apr 13, 2014 | 2004 Ford F-250 Super Duty
Dec 14, 2017 | 1997 Nissan Maxima
Mar 01, 2014 | 2001 Mercury Grand Marquis
Jul 08, 2013 | 1997 Toyota Avalon
Dec 14, 2009 | 2005 Mazda RX-8
Aug 28, 2009 | 1995 Ford F150 Styleside Regular Cab
Aug 24, 2008 | Mitsubishi Galant Cars & Trucks
Dec 21, 2019 | Cadillac Cars & Trucks
15 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: