My tach on my boat with an 85 Johnson 150hp, stopped working while at the lake this weekend. It works good up to about 2000-2500 rpms and then drops to 0 when you get past it. Any insight would be great. thanks, Bob
one more clue, when sitting docked and using the fast idle set at about 2000, if I lightly touch the trim buttons, the tach will bounce. Thanks for the reply schematic, I will try to check the retifier. Any details on this test that you could shed on me? Thanks
I would check all grounds.....<br /><br />The rectifier is nothing more than four diodes. To check them, you will require a digital multimeter with a diode test function, or an analog (needle type) meter with an ohmmeter function set to RX1.<br /><br />
Bumurray<br /><br />There is a teleflex technical note for certain johnrudes from that era with very similar symptoms to yours. It requires a resister to fix. Check page 4 of this link<br /><br /> http://www.tflx.com/PDF/99320.pdf
great info, I will look into this. The only thing that bothers me is that it was working until I took off with the motor in the tilt and it slammed down to the trim rods. This is when it started doing this. Thanks for the info.
