1999 BF 130 Tach not working

"My tach is not working.

I&

"My tach is not working.

I've checked continuity between the (grey) wire at the tach and the appropriate pin on the ECU's wiring harnesss off of the ECU itself - it's there.

I then checked the signal on the wire at the tach with an osciloscope, nothing's there. Just some minor engine noise. I can't get to check the lead itself off of the ECU becuase I would have to unplug it to access the output signal.

Any ideas?

Just a note - the trim gauge doesn't work either

Thanks, Zig"

"You have probably already don

"You have probably already done this but...

Have you disconnected the tachometer itself and checked the output to ground with no load. If the tach itself is bad, it may be causing signal problems.

Are you using a good engine ground in your measurement? Does you scope measure dc as well as ac. I am not sure if the signal is ac or dc. I need to take the time and check sometime.

If the tach and trim gauge are not working, their issues may or may not be related.

With the key switch on, do you measure 12v at both gauges? If so, your grounds to the gauges are probably good. If not, it is time to do some more tracing.

If continuities are good, voltages are good, etc.,the trouble shooting guide suggests trying a known good ecu. Hope you have a buddy that has a 115HP or 130HP (same ecu)"

"Thanks Mike.

No, I kept th

"Thanks Mike.

No, I kept the signals on the tach while measuring. That's a good suggestion. I'll try that.

I used the ground wire to the tach for ground - this ultimately runs to the ground block. I didn't have enough wire handy to get back to the engine to get a solid ground.

Yep, scope measure both ac/dc. Someone told me that the signal is AC +/- 5 volts, and I read somewhere that it's mV's DC. Neither showed up.

There is 12 V's there on both gauges w/the key switch turned on.

I don't have buddy w/a 115 or 130 - at least yet. Time to find one!

I'm putting her in the water for the remainder of the year this weekend - if I don't have the chance to get this fixed, then I'll just have to run her w/out the tach.

I'll post again if I find anything worthwhile, hopefully can help somebody out in the future."