Engine Monitor Installations
Not all Engine Monitor installations are equal.
A quality installation should utilize installation practices that are compatible with the surrounding compartments and environment it is installed within. The finished product should at a minimum meet or exceed the OEM design criteria. Portions of this installation are protected from environmental elements inside the Aircraft Cabin, however, other portions are installed throughout the exterior Airframe and Engine compartment.
Special consideration due to the various surrounding areas should be taken into account, therefore installation practices will vary and quite often don’t. Avionics facilities can do a very clean installation under the Instrument Panel. However, they tend to fall short regarding areas throughout the exterior Airframe and Engine compartment. This often leads to damaged wiring and premature failure of Probes & detailed components within the Engine Compartment.
Your average A&P, on the other hand, might utilize good practices within the Engine compartment & transducer arrangement however when it comes to Panel wiring fall short with things such as expansion loops and proper installation techniques lacking the quality crimping tools that are often found in Avionics Shops. Very few A&P Mechanics, as well as Avionics Technicians, are not familiar with MIL-W-5088 a Military Specification for Aerospace Wiring that is utilized by all the Aircraft manufacturers in some form when your Aircraft were initially manufactured. In fact, until recent years the FAA itself hasn’t given much thought to wiring standards until the introduction & rewrite of FAA AC43.13-1B Chap.11.
You can view various examples on the following link of proper and some “improper” installations found on various Aircraft.
With my involvement with such organizations as CPA (Cessna Pilots Association), CPS (Cessna Pilots Society) and other Cessna groups over the years as well as Manufacturers such as JPI, EI, Insight I find that likely 80-90% of the Engine Monitor Failures or problems can be traced back to Installation errors.