Checking Aftermarket Accessories

Checking Aftermarket Accessories

Do not connect aftermarket accessories into the following circuits:

Caution: Refer to SIR Caution (SIR Caution) .
* SIR circuits, all such circuits are indicated on circuit diagrams with the SIR symbol.

Notice: Refer to OBD II Symbol Description Notice .

* OBD II circuits, all such circuits are indicated on circuit diagrams with the OBD II symbol.


Always check for aftermarket accessories (non-OEM) as the first step in diagnosing electrical problems. If the vehicle is so equipped, disconnect the system to verify that these add-on accessories are not the cause of the problems.


Possible causes of vehicle problems related to aftermarket accessories include:

* Power feeds connected to points other than the battery
* Antenna location
* Transceiver wiring located too close to vehicle electronic modules or wiring
* Poor shielding or poor connectors on antenna feed line
* Check for recent service bulletins detailing installation guidelines for aftermarket accessories.