2005 Mercury Mariner Q&A
2005 Mercury Mariner Question: The vehicle alarm is going off randomly.
The body control module can be scanned for trouble codes. Have this done and it should help with diagnosis. IF factory alarm. - pushrod
Have the right rear door switch checked. Has the vehicle ever had any body work? - ziptie12
I have a shop in Brownsburg, Indiana and had this problem not to long ago with another Ford. Wetry is correct on it is more than likely a BCM (Body Control Module) problem IF the alarm is factory istalled. Ford has many problems with contamination of BCMs and fuse boxes getting water and subsequent corrosion on them. Unforunately the easiest test(s) that can be ran on this vehicle involves a fairly expensive scan tool. This makes it a very simple diagnosis even if no codes. If you have access to one or even for your own knowledge whomever is looking at the live data for the BCM should look at system voltage. If faulty its almost always going to have an off the wall battery voltage reading. EX-22 volts. Really anything that isnt 12.4-14.2 on a constant basis. Thanks! - fordnut3