F150 (2005 Model) will not start but have power to starter relay

[Doublebarrel]

I have a 2005 F150 on a Pathfinder boat. Motor runs great, has been taken care of, always connected to trickle charger and garaged except for fishing days. Have had a problem for a number of years that I attributed to grounding issue, but not sure now. Went fishing yesterday and boat would not start at the ramp. Can hear starter relay click but will not try to start or turn over. Ran it at home the evening before and started right up and ran for 30 minutes. Drove home and the boat started. I brought it to the dealer for this 3 years ago and they said it was the ignition switch and replaced, but did the same thing about 6 months later. Did some research and cleaned and tightened every ground. It still occasionally will not start, but will eventually start. After I got home yesterday I cleaned and tightened all grounds. They all looked good. Voltage at battery is 12.57V key off and 12.47V key on. Voltage at battery and main ground (not battery ground) is 12.45V key off and 12.43V key on. Voltage at starter solenoid is 12.56V key off and 12.45V key on. Boat currently doesn't start, but I am getting power to the start relay as I can hear it click when I try to start. I have inspected every connection for corrosion and if loose and everything looks good. I checked the ignition switch and fine. On the safety switch when I remove the safety lanyard (plastic key) I have continuity and when I turn the key I get power to the start relay. I also have continuity when the lanyard is engaged for starting. Not sure if this could be the problem. Looking for some help as I am confused as to what can be causing this when I drive to the boat ramp and it doesn't start and drive home and it does. Loose connection? Any ideas and advice are appreciated. Thanks

[pstephens46]

Google voltage drop testing. You can test individual site runs. Helps to have two people and long meter leads with alligator clips.

....supposed to read wire/lead runs....

[TownsendsFJR1300]

Very, very likely, your starter relay is shot.

Part #4, hidden under a plastic cover, port side is where it's located: https://www.boats.net/catalog/yamaha...d/electrical-2 part #4

When mine failed, you could hear it click, but little power to the starter due to burnt up contacts inside.

You can double check by attaching a ground (from a good battery), to the block, then positive direct to the starter. The starter / engine should turn over.

I cut mine apart to see the guts / failure and the below pic shows the burnt contacts (inside) not allowing sufficient current to the starter. In a pinch, you can jump those two terminals, (bypass the relay and the engine will spin over).

They do fail...



Expect your T&T relay to be next (and a bit more expensive)

[fairdeal]

as Scott explains, based on your description, sounds likely that the starting relay is intermittently bad.
the relay is a "remote con*****ed switch" - using an "electromagnet"
when you turn the key to crank, it sends power to activate the electromagnet in the relay -
that's the the "click" you hear
and then the switch contacts (which Scott show) should connect the two big wires
so that battery power goes to the starter motor.

to test, or in a pinch, YOU can "be the switch" - slide down the protective rubber boots,
take a big ol' piece of metal and shove it across those terminal nuts-
the starter should run

(btw, the kill switch has nothing to do with whether or not the starter runs.

however, the neutral switch inside the shift/throttle control does play an important part -
the power from the keyswitch has to pass through it
to get to the starting relay)

[pstephens46]

His voltage readings don’t sound too terribly strong. 12.4 will barely crank my motor.

[Doublebarrel]

pstephens46 - Thank you and I did do some resistance testing with my ohmmeter and everything checked out and all wires are sealed and looked good. Since I fish salt water I am always checking my grounds and wire resistance on my trailer to fix my lights.

townsendsfjr1300 and fairdeal - Thank you. I jumped across the terminals and the starter fired right up. I will order the starter relay. I thought it would be this, the neutral safety switch or the safety kill switch. I am still confused on the kill switch in that I get continuity when safety key is installed and not installed. One last question, I know where the brown wire goes, but the red wire on the relay, I assume, goes into one of the two wire bundles back behind the fuse box. I always like to go back to the source when replacing something so I assume the best route is to remove the electrical tape and connect with a crimp connector unless y'all advise the red wire goes past the two wire bundles / harnesses. Thanks again.

[fairdeal]

pstephens46 - One last question, I know where the brown wire goes, but the red wire on the relay, I assume, goes into one of the two wire bundles back behind the fuse box. .

when changing the relay the wiring is "plug and play"
one lead is a ground - a ring terminal that is bolted to the block
the other lead has a bullet connector

[TownsendsFJR1300]

when changing the relay the wiring is "plug and play"
one lead is a ground - a ring terminal that is bolted to the block
the other lead has a bullet connector

+1 ^^^.

The connector is right behind the unit.

It'd take longer to replace the connector than to just un-plug and re-plug.

It's very easy to swap out...Might want to put a rag under where your working. Those screws are attracted to the lower cowl.


*Also, I'd get that battery load tested, as Pat posted, the voltage is pretty low (maybe 50%). Once cranked up, check your running /charging voltage-should be around 14 volts...

[Doublebarrel]

Thanks guys. Took me 20 minutes to replace the relay starter and she fired right up. I will check the running voltage this weekend with my meter. The Yamaha gauge usually shows 13.8 volts. I am considering going from a size 24 to a 27 battery since I also run a live well from this battery. Thanks.

[TownsendsFJR1300]

Thanks guys. Took me 20 minutes to replace the relay starter and she fired right up. I will check the running voltage this weekend with my meter. The Yamaha gauge usually shows 13.8 volts. I am considering going from a size 24 to a 27 battery since I also run a live well from this battery. Thanks.

Great!

BTW, that engine calls for a group 27 battery. I had to increase mine when I re-powered.. Pat also runs a group 27 battery.

My Yamaha gauge shows about the same voltage running.

[pstephens46]

Great!

BTW, that engine calls for a group 27 battery. I had to increase mine when I re-powered.. Pat also runs a group 27 battery.

My Yamaha gauge shows about the same voltage running.

May want two batteries if running a live well for a long period. Maybe hook up the isolator lead to second battery to keep it charged for the run back from fishing if needed.

[Doublebarrel]

Thanks again guys. Boat is starting perfect. I cut open the starter relay and one of the contacts
was burned. Not sure how this happens, but happy I didn't take to the boat dr.

[TownsendsFJR1300]

Thanks again guys. Boat is starting perfect. I cut open the starter relay and one of the contacts
was burned. Not sure how this happens, but happy I didn't take to the boat dr

Just wear and tear. My 06 F150 starter relay contacts:

[99yam40]

Thanks again guys. Boat is starting perfect. I cut open the starter relay and one of the contacts
was burned. Not sure how this happens, but happy I didn't take to the boat dr.

Dc is bad about arcing when opening up the contacts.
that is why the old points had condensers.

once a point surface gets a little oxidized and it causes resistance when made up, which causes heating as more current flows

[rodbolt17]

and remember, if you add a second battery your engine shipped from japan with an isolator. you can charge a second battery that is not part of the starting battery.