I found out today that when I reworked my transom over the winter that I apparently installed the trim and limit senders incorrectly. I replaced both of the senders when I did the transom overhaul on my boat. I have a 92 Wellcraft 197 Eclipse with a 4.3 Mercuiser/Alpha 1 (Gen 1) drive. The drive trims up and down with no problem. The dash trim indicator is now pegged at full trim.
The symptom was that when trying to adjust the trim sender it wouldnt slowly change the trim angle, it seemed like it was either on or off. Hooked up the multimeter and sure enough it was the limit switch (continuity either on or off). The trim sender wire does indeed show a resistance value that can be changed by rotating the sender.
When I switched the wires (limit and sender) the trim gauge went full scale and did not respond to rotating the sender. The gauge is now at full trim and doesnt change no matter what I do (it did at least change when the limit sender was hooked up to it). Now the questions:
1.I assume that the polarity of the two wires does NOT matter. I am thinking resistance is resistance, and there is either on/off for the limit. Is that a correct assumption?
2.Does the resistance value get changed into a voltage before it is sent to the trim gauge? I am trying to determine who to troubleshoot the signal at the back of the gauge to see if the right signal is getting to the gauge.
3.The trim gauge has a hot and ground for the light bulb, and two hots (I guess) on the bottom of the gauge one was a fixed low voltage and the other was 12V. Can anyone give me a trim gauge primer? How do they work.
Thanks very much for the help. I am in the boonies and there arent any good marine mechanics here. I will have to see if I can correct this one myself.
The symptom was that when trying to adjust the trim sender it wouldnt slowly change the trim angle, it seemed like it was either on or off. Hooked up the multimeter and sure enough it was the limit switch (continuity either on or off). The trim sender wire does indeed show a resistance value that can be changed by rotating the sender.
When I switched the wires (limit and sender) the trim gauge went full scale and did not respond to rotating the sender. The gauge is now at full trim and doesnt change no matter what I do (it did at least change when the limit sender was hooked up to it). Now the questions:
1.I assume that the polarity of the two wires does NOT matter. I am thinking resistance is resistance, and there is either on/off for the limit. Is that a correct assumption?
2.Does the resistance value get changed into a voltage before it is sent to the trim gauge? I am trying to determine who to troubleshoot the signal at the back of the gauge to see if the right signal is getting to the gauge.
3.The trim gauge has a hot and ground for the light bulb, and two hots (I guess) on the bottom of the gauge one was a fixed low voltage and the other was 12V. Can anyone give me a trim gauge primer? How do they work.
Thanks very much for the help. I am in the boonies and there arent any good marine mechanics here. I will have to see if I can correct this one myself.
