1. Check the Bulbs:
* All Bulbs: Start by checking *all* the bulbs in the affected turn signal circuit (front and rear on the same side). A burned-out bulb, or even one with a weak filament, will cause the rapid flashing. Replace any burnt-out bulbs with the correct wattage. *This is the most likely culprit.*
* Grounding: Ensure the bulbs are properly seated. A loose connection can cause intermittent or erratic flashing.
2. Check the Turn Signal Fluid (if applicable):
* Just Kidding: There's no turn signal fluid. This is a common myth.
3. Check the Flasher Relay:
* Location: The flasher relay is a small electrical component, often located under the dash, in a fuse box (under the hood or inside the car), or sometimes even behind the glove box. Consult your owner's manual to find its exact location. It might be labeled "turn signal flasher" or something similar.
* Replacement: If you find it, try replacing the flasher relay. They are inexpensive and easily swapped. Make sure you get the correct type for your Pontiac Montana.
4. Check for Shorts or Wiring Issues:
* Visual Inspection: Carefully inspect the wiring harness related to the turn signals. Look for any frayed wires, broken insulation, or corrosion. Pay close attention to the wiring near the affected bulbs and the connections.
* Continuity Test (Advanced): If you have a multimeter, you can test the continuity of the wiring to ensure there are no breaks or shorts. This requires some electrical knowledge. A short circuit can cause rapid flashing.
* Professional Help: If you're uncomfortable working with car wiring, this is a good time to seek help from a qualified mechanic.
5. Consider the Multi-Function Switch (Turn Signal Switch):
* Possibility: In some cases, a failing multi-function switch (the stalk that controls your turn signals, wipers, etc.) can cause this issue. This is less likely than a bad bulb or flasher relay. This would generally cause issues in both left and right signals.
Troubleshooting Steps Summary:
1. Check Bulbs (MOST LIKELY): This is the easiest and most common fix.
2. Replace the Flasher Relay: This is the second most likely solution.
3. Visual Inspection of Wiring: Look for damage.
4. Professional Diagnosis (If Needed): If you can't find the problem, a mechanic can properly diagnose the issue.
Remember to always disconnect the negative battery terminal before working on any electrical components in your car. Safety first!
