2004 Can a malfunctioning Garmin GPS screw with the cars performance?

This site contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

It may. I think you should have your battery tested to be sure it is in good condition.
 
A weak/failing battery can cause all kinds of problems.
 
I don’t see how a plug-in Garmin can affect anything. They only draw milliamperes of current and use passive antennas.
 
Back
Top