Mercury Blues
Cadet
- Joined
- May 20, 2008
- Messages
- 7
Had the water pump go on my boat while I was out. Overheated, but seems to work fine, except the tach does not work. Had some melted insulation on the wires, but repaired them. Just happy it started up OK.
Motor is a 1998 Merc Outboard 135 Hp with 40 amp stator, and dual voltage regulators.
- Connection from regulator grey wire to guage - OK, All other power to the guage checks OK.
- Switched tach signal (grey wire) from one regulator to the other regulator spare signal terminal - nothing.
- Checked voltage at battery terminals with engine running (12.7 DC volts start and goes to 14 volts when idling higher, so battery appears to be charging). Switch onto AC, reading is 27 VAC
- Tach signal at guage when connected 17.4 VAC. Multimeter not on DC setting, because it apparently is a pulse signal. If I measure from the signal wire to ground, with signal disconnected from the guage Reading = 24 VAC. (Are any of these voltages on the high side.)
- Tach Zeros when started. Had a spare tach and it operates the same. If I tap the signal wire to the tach post, the guage needle moves. Someone told me to remove the signal wire, and short 12VDC and the tach signal post but nothing happens.
I am not sure if both regulators are shot, or something else is going on here, but any advise would be helpful.
Gregg
Motor is a 1998 Merc Outboard 135 Hp with 40 amp stator, and dual voltage regulators.
- Connection from regulator grey wire to guage - OK, All other power to the guage checks OK.
- Switched tach signal (grey wire) from one regulator to the other regulator spare signal terminal - nothing.
- Checked voltage at battery terminals with engine running (12.7 DC volts start and goes to 14 volts when idling higher, so battery appears to be charging). Switch onto AC, reading is 27 VAC
- Tach signal at guage when connected 17.4 VAC. Multimeter not on DC setting, because it apparently is a pulse signal. If I measure from the signal wire to ground, with signal disconnected from the guage Reading = 24 VAC. (Are any of these voltages on the high side.)
- Tach Zeros when started. Had a spare tach and it operates the same. If I tap the signal wire to the tach post, the guage needle moves. Someone told me to remove the signal wire, and short 12VDC and the tach signal post but nothing happens.
I am not sure if both regulators are shot, or something else is going on here, but any advise would be helpful.
Gregg
