Tach stopped but engine ran now it won’t crank MPEM?

[Lakedweller]

1998 Challenger 1800 twin 787. Following a dead battery from bumping the light switch while covering the boat after recharging the battery the starboard tach quit. The engine ran ok for two days then yesterday following a normal shutdown the engine won’t crank. Beeps are normal when plugging in the DES. Port engine runs fine. All fuses checked OK

Any thoughts?

 

[Dr Honda]

The tach only has 3 wires. (well, 4 with the internal light) Power, and signal. The signal wire goes directly to the stator, and watches the pulses. The power is obvious. So... do the other gauges power up? If they do... sounds like you have some dirty connections up I the helm. If nothing else is powering up... then the MPEM may have issues.


I guessing you just need to clean some connections.

 

[Lakedweller]

Jumped the starter but no spark when the engine cranked. Looks like the MEPM for the starboard engine is cooked. The new one comes this week.

 

[Lakedweller]

But after replacing the MPEM the same problem exists. After switching parts between engines we find the starter solenoid is bad. And the tach quit the same day. I hate electrical problems.
Sent the tach to farina beds in CT for repair.

 

[Lakedweller]

New solenoid arrived today and everything is running. Just a hole in the dash where the port tach was. Hope it comes back repaired soon.