Grand Cherokee 2WD L6-4.0L VIN S (1997)
Hazard Warning Flasher: Description and Operation
SYSTEM OPERATION
The combination flasher is a smart relay that functions as both the turn signal system and hazard warning system flasher. The combination flasher
is designed to handle the current flow requirements of the factory-installed lighting.
If supplemental lighting is added to the turn signal lamp circuits, such as when towing a trailer with lights, the combination flasher will
automatically compensate. This allows the flash rate to remain the same, regardless of electrical load increases. However, if a bulb fails in the turn
signal lamp circuits, the flash rate of the remaining bulbs in that circuit will increase to 120 flashes-per-minute, or higher.
While the combination flasher shares the terminal orientation (footprint) of a International Standards Organization (ISO)-type relay, the internal
circuitry is much different. The combination flasher contains active electronic integrated circuitry elements. Do not substitute any other relay for
the combination flasher.
The combination flasher cannot be repaired and, if faulty, it must be replaced. Also, because of the active electronic elements within the
combination flasher, it cannot be tested with conventional automotive electrical test equipment. First, if the combination flasher is believed to be
faulty, test the turn signal and hazard warning system circuits. Then, replace the combination flasher with a known good unit to confirm system
operation.
CIRCUIT OPERATION
When the operator selects the hazard flashers, the multi-function switch circuit L12 from the flasher relay circuits L60, L61, L64 and L65.
Circuit L61 feeds the left rear turn signal lamp. Circuit L60 feeds the right rear turn signal lamp. Circuit L65 feeds the left front turn signal lamp,
side marker lamp and the instrument cluster indicator lamp. Circuit L64 feeds the right front turn signal lamp, side marker lamp and the instrument
cluster indicator lamp.
Circuit Z1 provides ground for the hazard flasher lamps.
