Tech Tip: Cadillac Blower Motor Failure – UnderhoodService

Tech Tip: Cadillac Blower Motor Failure

Owners of mid-90s Cadillac Eldorados, Sevilles and Concourses, equipped with the 4.6-Liter Northstar engine, may experience a heater blower motor failure after performing service to the right bank of spark plugs, spark plug wires or ignition control modules.

Along with a replica of Leonardo Da Vinci’s masterpiece "The Mona Lisa" created from 65 pieces of toast, shrunken heads and tornados capable of driving a piece of straw into a tree, this Cadillac tech tip qualifies as one of those strange "Believe It Or Not" stories.

Owners of mid-90s Cadillac Eldorados, Sevilles and Concourses, equipped with the 4.6-Liter Northstar engine, may experience a heater blower motor failure after performing service to the right bank of spark plugs, spark plug wires or ignition control modules.

I told you this was strange. The reason for this malady may be that the spark plug wires are routed incorrectly and lying near or contacting the blower motor housing. Under normal operating conditions, low frequency voltage discharges emitting from the right (rear) bank of spark plug wires may affect blower motor operation and /or cause the blower motor to fail.

The repair is simple. When servicing right (rear) bank engine ignition components, exercise caution when installing the spark plug wires. Spark plug wires must be routed away from the firewall mounted blower motor. Refer to the illustration for proper routing. By the way, blower motor operation will not affect the ignition system…"Believe It Or Not."

Written by ALLDATA Technical Editor, Rich Diegle. Rich is an Advanced Engine Performance Certified and ASE Master Technician with an Associate of Arts degree in automotive technology and 22 years of dealership and independent shop experience.

Courtesy of ALLDATA.

For additional information, visit www.alldata.com.

You May Also Like

Check The TSBs!

With the complexity of today’s modern vehicles, as technicians, we are going to have to stay on top of our game.

Over the last 28 years of being a technician, I have developed the habit of checking for and reading technical service bulletins at the forefront of the diagnostic process, especially when an unfamiliar vehicle exhibiting blatant or straightforward concerns comes into the shop. I have found many valuable nuggets of information while reading over these bulletins, from wiring concerns and connector issues, to transfer noises, water leaks, and engine and transmission performance concerns. The knowledge gained in reading through these bulletins has not only helped me with the vehicles I’m working on, but also increased my perspective and ability to connect the dots on other vehicles that don’t pertain to a current bulletin.

HVAC Heat Pumps

In theory, heat pumps can be three to four times more energy-efficient than conventional electric heaters.

AMN Drivetime: Cal Ganda’s Continental Journey

Ganda embodies servitude leadership, prioritizing team success and customer-centricity.

Auxiliary Water Pump Diagnostics

A car or truck comes into your shop with a complaint of poor heater performance- the issue may be the auxiliary water pump.

Misfire Codes P0300, P0301-P0312 and P0313+P0314

The only way to clear the code is to use a crankshaft position relearn with a scan tool.

Other Posts

Eaton to Supply ELocker Differential System to EV Manufacturer

The system leverages an electric motor to power the rear wheels and an electric motor or an optional ICE driving the front wheels.

Replacing Your Power Steering Reservoir

Discover why simply flushing out contaminants from power steering reservoirs may not be sufficient to prevent potential failures.

What Caused The Turbo To Fail?

Up to 50% of turbocharger failures are due to oiling problems.

Eli Opens Reservations for its Micro-EV in the US

The new Eli ZERO represents a new category of high-tech, efficient and sustainable micro-EVs, according to Eli Electric Vehicles.