Tach Reads Zero

[Reel Kahuna]

I went fishing is morning and when I launched I noticed that the digital Yamaha Tach connected to my 2004 F150 hp read zero. It wouldn't register the rpm...just stayed at zero. I won't be able to check the connections until tomorrow but forecast calls for heavy rain so thought I'd ask here tonight to get possible cause?

[WET-BOX-MARINE]

check the green wire on the voltage regulator on motor

[Reel Kahuna]

check the green wire on the voltage regulator on motor

Will do when today's storm moves out. Wind predicted to be 50 mph to 70 mph. Thanks for your reply.

[WET-BOX-MARINE]

yea its nasty here in the bay area

[rodbolt17]

I just gotta ask.
why bother checking ANYTHING on the regulator or charging system for a tach failure on an F150 or most any other late model V yamaha?
inquireing minds wanna know.

[WET-BOX-MARINE]

does the tach get its signal from the regulator????

or they got rid of that in the later models

[rodbolt17]

been many years since the majority of Yamaha engines that utilize ECU's and pulsr coils have taken an analog signal from the rectifier.
mostly now its on the tiny mite engines,less than 4 HP.
if in doubt always look at the rectifier wireing if it connects to the tach green wire its an analog signal.
if not its generated by the ECU.
some use a pulser signal some use the crank position signal.
however its easy to see on the harness diagram.

[Reel Kahuna]

We finally got a morning without any rain and I was able to dis-connect the tach connectors from the motor, control box and behind the tach then cleaned each and plugged them back accordingly. Whoo Hoo...tach works!! Headed out tomorrow for a little Striper *****ing.
Thanks all .

[WET-BOX-MARINE]

good deal!!!!!!!!!!!!!