Erratic tach readings
Posted: Mon Jun 06, 2016 6:47 am
Unravelling the mysteries of a new to me boat.
Tach readings were almost unusable a few weeks ago. Port motor read 3K RPM at idle. Starboard bounced around at 3K plus.
I cleaned up all the grounds in the bilge and coated with dielectric grease. Cleaned all ignition connections at the motors. Found the ballast resistors were bad which was causing the ECM to overheat and the potting to melt. Replaced the ECMs and resistors both motors. For grins, I replaced the starter solenoids. Had two in the spare parts bin.
Found the stereo and four other 12V accessories were grounded to the voltage gauge at the lower helm. Rerouted these wires to the grounding bar under the helm.
Anything other places to look?
Tach readings were almost unusable a few weeks ago. Port motor read 3K RPM at idle. Starboard bounced around at 3K plus.
I cleaned up all the grounds in the bilge and coated with dielectric grease. Cleaned all ignition connections at the motors. Found the ballast resistors were bad which was causing the ECM to overheat and the potting to melt. Replaced the ECMs and resistors both motors. For grins, I replaced the starter solenoids. Had two in the spare parts bin.
Found the stereo and four other 12V accessories were grounded to the voltage gauge at the lower helm. Rerouted these wires to the grounding bar under the helm.
Anything other places to look?