Diagnosing issues with your Sea-Doo can sometimes lead you down a path of electrical troubleshooting, and the ignition coil is a critical component in ensuring your personal watercraft runs smoothly. One key test you can perform is an Ignition Coil Test, specifically focusing on the pickup coil, which is vital for triggering the ignition at the right moment. This guide walks you through a practical approach to testing your Sea-Doo’s pickup coil, drawing from real-world troubleshooting experiences.
When diving into the magneto harness plug of a Sea-Doo, you’ll typically find a set of wires, each serving a specific function. In many configurations, you’ll encounter six wires: three yellow wires usually associated with charging, a black wire for ground, and then the crucial wires for the pickup coil – often identified as black/yellow and yellow/white.
To test the pickup coil, a resistance test is generally recommended. Ideally, you would use a test adapter as suggested in the service manual. However, if you don’t have access to this specialized tool, you can still perform a test by accessing the wires at the MPEM (Multi-Purpose Electronic Module) connector, which is at the other end of the harness. This allows you to test the resistance remotely.
The service manual might instruct you to test the resistance between the black/yellow wire and a WHITE wire on a test harness. However, at the magneto plug itself, a white wire might not be present. In this case, understanding the wiring diagram and potentially referencing the white wire at the ignition coil itself can be helpful. By reconnecting the plug at the magneto housing and accessing the rear harness plug at the MPEM, you can proceed with testing the pickup coil resistance.
Looking at the MPEM plug, you can identify the pins for the black/yellow and yellow/white wires. Often, these are situated in the top row, second and third from the right. When testing the resistance between these two pins with a multimeter, an “infinite resistance” or “open circuit” reading indicates a potential issue with the pickup coil. This suggests a break in the coil’s internal wiring, preventing the necessary signal from being generated.
Further investigation might involve checking the resistance between the black/yellow wire and the white wire, if identifiable at the MPEM plug (often top row, third from the left). Again, an infinite resistance reading here, regardless of whether the white wire is connected at the ignition coil, can reinforce the diagnosis of a faulty pickup coil.
If your ignition coil test reveals an open circuit in the pickup coil, it strongly suggests that the pickup coil has failed. The next logical step would be to replace the pickup coil. This often involves removing the magneto housing cover. Common procedures mentioned in repair discussions include steps like removing the exhaust pipe, supporting the engine, and detaching the front engine mount to gain access to the magneto cover, especially the bottom bolt which can be challenging to reach.
When undertaking this repair, a common question arises: Is it possible to replace the pickup coil without disconnecting all oil lines and the oil pump cable from the carburetors? Consulting your service manual and possibly seeking advice from experienced Sea-Doo mechanics or forums can provide insights into shortcuts or alternative methods that might simplify this repair process while ensuring everything is reassembled correctly and safely.
In conclusion, performing an ignition coil test, specifically focusing on the pickup coil resistance, is a crucial step in diagnosing ignition problems in your Sea-Doo. An open circuit reading during this test often points to a faulty pickup coil requiring replacement. By understanding the wiring and following a systematic approach, you can effectively troubleshoot your Sea-Doo’s ignition system and get back on the water.
