Rear blower motor fuse blows 1999 Cadillac Seville STS

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Mar 172019

The fuse for the back heater blower blows when I start the engine. It will run perfect with the key in accessory position but as soon as the engines started the fuse blows .. please any ideas what the issue could be. Any help will be appreciated.

The rear blower motor fuse (Fuse #28 10 amp) is the fuse you are describing. As a test for the blower motor circuit, remove the rear blower motor relay(RR BLO Relay). If the fuse still blows you for certain it has nothing to do with anything downstream from the relay in that circuit. Use the provided wiring diagram for reference.

1999 Cadillac Seville Rear Blower Motor Wiring Diagram


Mar 022018

1992 Cadillac Fleetwood

My car is idling too fast. I have a red light “inflation” button, and then also check engine light on and off. The idle will go fast, sometimes I can kick it down and then it increases again. What is the likely cause?

High Idle Casue

Vacuum leak.

Anytime there is a vacuum leak you can expect the rpms at idle to increase. The engines sensors know there is an increase of air and it compensates by adding extra fuel. Also with the check engine light on it is a good idea to check the codes. Since this vehicle is older than 1995 the codes can be read without a scan tool.

Dec 172017

2006 Cadillac CTS

Location of the TCM. Does a used one from another CTS need to be reprogrammed?
Does this this cause a engine reduce power message?

The engine reduce power message has to do with the TAC system. Throttle Actuator Control(TAC) is your electronically controlled throttle. In most cases the the throttle body(TAC System) will need to be replaced. In some cases a software update may cure the issue. And in rare occasions simply unplugging the battery for a few minutes works.

For whatever reason you want to swap out the TCM with a used one, you may need to reprogram it.

Transmission Control Module(TCM)

TCM(8) is located at the right front of engine compartment.

TCM location - 2006 Cadillac CTS

Transmission Control Module Programming and Setup

The transmission control module (TCM) must be programmed with the proper software/calibrations. Ensure that the following conditions exist in order to prepare for TCM programming:
– The battery is fully charged.
– The ignition switch is in the RUN position.
– The Techline equipment cable connection at the data link connector (DLC) is secure.
Program the TCM using the latest software matching the vehicle.
If the TCM fails to program, proceed as follows:
Ensure that the TCM connection is OK.
Inspect the Techline equipment for the latest software version.
Attempt to program the TCM. If the TCM still cannot be programmed properly, replace the TCM.

Dec 152017

Cadillac Coupe Deville

What can happen when you air conditioner gets charged with the wrong Freon?

Short answer: you will get this mixture of GOO, in your system, that will burn up your compressor in a very short time. Therefore R12 and r134 cannot be mixed… they are incompatible and don’t work as a mixture.

Wrong Freon

Being a 1993 the air conditioning system originally required R-12 Freon. If at anytime it was converted to R-134a Freon, the installation ports would have been changed to only accept the newer style Freon. This makes it difficult to add the wrong type of Freon.

If for some unforeseen reason the two were intermixed, the entire system will need to be flushed. The orifice tube, o-rings and accumulator will need to be replaced as well. And if the system was operated with the contaminated Freon, you may also need to replace the Compressor.


Jun 192017

Cadillac DevilleHow to replace heater/vent blend door actuator?

Blend Door/Air Temperature Actuator Assembly Replacement

Removal Procedure

Blend Door Acutator

  • Remove the instrument panel compartment.
  • Disconnect the electrical connector from the air temperature actuator assembly (2).
  • Remove the air temperature actuator assembly (2) retaining screws (1).


  • Remove the air temperature actuator assembly (1).

Installation Procedure

Important The passenger air temperature actuator must be properly aligned with the temperature door shafts prior to installation on the vehicle.

  • Test fit the actuator to verify alignment of the cams on the replacement air temperature actuator with the temperature door shafts. If the cams and shafts are out of alignment, adjust the shafts first and proceed to cam adjustment only if necessary.
  • To adjust the shafts, do the following:
  • Rotate the inner and outer shafts slightly rearward. The shafts have a limited range of travel and should not be forced.
  • Test fit the temperature actuator to the shafts. Be sure to align the inner shaft first.

Important The following steps will set an out range trouble code for the actuator. Be sure to erase this code when the repair is complete.

  • To adjust the cams, do the following:
  • Install the electrical connector to the actuator.
  • Hold the actuator away from the shafts and turn the ignition to ON. The actuator will enter the automatic re-calibration mode. The cams will continue to turn until the ignition is turned to OFF.
  • Observe the motion of the cams on the actuator and turn the ignition OFF when the cams are aligned with the position of the temperature door shafts.
  • Test fit the temperature actuator to the shafts. If necessary, repeat the cam adjustment.
  • Install the air temperature actuator assembly (1) to the HVAC module.


Caution! Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  • Install the air temperature actuator assembly (2) retaining screws (1).

Tighten the screws (1) to 1.4 N·m (12 lb in).

  • Install the electrical connector to the air temperature actuator assembly (2).
  • Install the instrument panel storage compartment.
  • Re-calibrate the actuators.
Apr 192017


TCS Light On

Here is what is going on,
(TCS) Security Light illuminate. Gas Gauge, Temp Gauge not working
Car starts and runs fine. Experience a little lag on acceleration.

Dealer has cut a new key and replaced some module under the driver seat. Issue still remains. After $800 and 3 days of no car, I took it out. Been living with this issue for a month now.
I checked all fuses and even replaced 3. All checks out. I’ve reset ECU and disconnected battery a few times. Visually inspected all wires for disconnect or wear and damage.
Could it be my cluster on the dash? I am personally going to run codes and see if my computer registers the temp and gas meter. If this is happening and the display is not working for my dash could that be where the problem lies?


Mar 202017

Cadillac CTSI need to check transmission fluid. Where is it located? Where is place to put trans fluid?


These days the transmission fluid isn’t designed for the consumer to access. This doesn’t however mean it can not be done. Though it may not be as simple as it may have once been it is still possible.

Transmission Fluid Replacement

Draining Procedure

  • 2005 CTS Transmission DiagramRaise and suitably support the vehicle.
  • Clean away all dirt and debris from the transmission fluid temperature sensor/drain plug area.
  • Place a suitable drain pan under the transmission.
  • Disconnect the electrical connector from the transmission fluid temperature sensor/drain plug.
  • Remove the fluid temperature sensor/drain plug (4).
  • Allow the system to drain.


  • Install the transmission fluid temperature sensor/drain plug (4).

Tighten the transmission fluid temperature sensor/drain plug to 18 N·m (13 lb ft).

  • Connect the electrical connector to the transmission fluid temperature sensor/drain plug.

Filling Procedure

  • transmission fluid fill plug 2005 CTSClean away all dirt and debris from the transmission fluid fill plug area.
  • Remove the transmission fluid fill plug.
  • Fill the transmission with DEXRON®-III transmission fluid, until even with the bottom of the fill plug hole.
  • Install the transmission fluid fill plug.

Tighten the transmission fluid fill plug to 18 N·m (13 lb ft).

  • Remove the drain pan.
  • Lower the vehicle.
Jan 242017

Cadillac DevilleCould I swap out the 4.6 and put in a Chevy 5.0?


I would not recommend this engine swap, though possible.

Cadillac LD8 4.6L Engine Swap

Anything is possible with the will and right set of tools. Therefore you’ll need to fabricate different mounts and adapters. Fabricate custom exhaust manifolds and pipes. Create all new wiring harness and change out engine computer. Not to mention the hood interference, etc.

The Cadillac 4.6L engine was designed for transverse applications where as the Chevy 5.0L engine was designed for rear wheel drive applications.

The LD8 (VIN “Y”) is a transverse V8 for front-wheel drive cars. Introduced in 1994, it is designed to provide more torque than the high-revving L37. The LD8 code had been used on all torque-tuned transverse Northstars, even as the exact engine specifications evolved. Compression ratio is 10.3:1 for engines built prior to model year 2000, and 10:1 for those built afterwards.

Oct 212016

1998 Cadillac SevilleMy vehicles engine overheats. It was losing water/coolant. Ive replaced water pump, thermostat, water reservoir, radiator hoses. Still the engine overheats. Vehicle runs fine until overheats. No smoke from tailpipe, no visible oil in the water or water in the oil. I did a pressure test. It loses pressure slowly but no viable fluid loss. I can hear air escaping somewhere but cannot determine where. Is this a head gasket problem or what test can I preform to determine problem. My vehicle has 118,000 miles has been sitting for 2 years before I purchased it.


Engine Overheats

Sounds like the cooling system needs to be bled. You shouldn’t be hearing air leaking, you should be seeing coolant spewing out. The engine overheats if there is an air pocket in the cooling system. Maybe check and or replace the radiator cap.

Refilling Coolant

  • Close the radiator drain cock.
  • Refill the cooling system. In order to ensure sufficient engine cooling, freezing and corrosion protection, maintain the coolant protection level at -37°C (-34°F) or lower.
  • Add a 50/50 mixture of DEX-COOL® and clean drinkable water to the cooling system.
  • Set the heater and A/C control to the highest setting.
  • Allow the engine to continue idling until the lower radiator to water pump hose becomes hot.
  • Allow the engine to cool to the outside temperature. Check the coolant level.

coolant resivior 1998 Cadillac Seville

(1) 1. Low Coolant Level
  • The coolant level should be to the full mark (1).