Turn signals not working on Grand Caravan
If you encounter a grand caravan turn signal not working situation, you can fix the problem yourself. Grand caravan turn signal problems are almost always caused by a fault in the multifunction switch. In order to understand how these newer “mux”
switches work, you have to throw away your electrical knowledge from the old days where the turn signal switch actually switched power to the flasher and then to the turn signal bulbs.
A mux switch doesn’t switch power to bulbs. It’s built with a series of resistors and is connected to the body control module (BCM). The BCM uses the multifunction switch as an input to tell it what you want the BCM to do. So the BCM provides voltage on one wire and depending on the return voltage, the BCM determines what action to take.
To remove the switch to test or replace, remove the three Philips screws holding the plastic cowling. The screws are accessed from the bottom of the cowling. Once the screws are removed, unsnap the cowling on each side.
To test the multifunction switch, use an ohmmeter and connect to the terminal pins in the switch.
When the switch is in the left turn position, expect to see 2.7Ω +/-5% between terminals 2 & 3
When the switch is in the right turn position, expect to see 1KΩ +/-5% between terminals 2 & 3
When moved to the high beam position, expect to see 2.32KΩ +/-5% between terminals 2 & 4
© 2015, Rick MuscoplatPosted on by Rick Muscoplat