1993 commercial 100 v4 - No power to Motor

[soburke]

Hi there,

a new boating season and a new problem, go figure! I have a 1993 commercial 100 v4, pulled her out of the garage this weekend, went through the cold start procedures. I used the trim to raise and lower the motor, she tried to start (starting motor engaged, flywheel turned, etc.) for a few and then died.

Tried again and the motor is dead. By that I mean the trim is not working it is not turning over, nothing. It is as if I shot a main fuse to the motor. I've done the following:

1. I have verified I have 12.5 volts at the battery, and to the motor. (tested at the motor connections)
2. Checked every fuse in the forward panel.
3. Tried to trim with the buttons on the motor and the remote, noting.

I am not sure what else to check. Feel like I am missing something simple as it appears to just be turned off. Starter solenoid?

Any help is appreciated, thank you.
Stephen

 

[KeyWestSkipper]

Re: 1993 commercial 100 v4 - No power to Motor

Hi Stephen, how old is that battery? Was it on a float charger? Do any other electronics like pumps and lights work?

 

[tashasdaddy]

Re: 1993 commercial 100 v4 - No power to Motor

disconnect the big Red harness plug. now jump the starter solenoid. this takes the harness and ignition switch out of the problem. if it turns over then, you have bad harness or ignition switch.

 

[Chris1956]

Re: 1993 commercial 100 v4 - No power to Motor

Steve, Does that motor have a fuse under the cowling? I couldn't find one on the drawings.

Sometimes they put an inline fuse near the starter solenoid. They use the solenoid as a connection point for fused power (usually red/purple wire) to the ign switch and trim system. if you do find blown fuse, you still need to figure out cause. Look for wires that have rubbed their insulation off or melted together.

 

[soburke]

Re: 1993 commercial 100 v4 - No power to Motor

Hey guys, thank you for all the informaiton. In sum:

1. the starter motor is brand new from WestMarine (as the one I bought last year was dead already, won't go there agian)
2. I followed the red one of the red lines from the top of the starter solenoid and it did have an in-line fuse...I removed, checked and it is BLOWN!

So I will go find another one and replace...but of course, my next question:

Why would it have blown? I have not played with the wiring as it has been stored since last year. New battery etc.

Any thoughts or is this "just one of those things that happens"?

I really appreciate the guidance.
Stephen

 

[jimdd810]

Re: 1993 commercial 100 v4 - No power to Motor

Somtimes fuses just go, not very often, But they do. Put in a new fuse and try it again.

 

[Chris1956]

Re: 1993 commercial 100 v4 - No power to Motor

Steve, You are likely to blow the new fuse, immediately upon turning the key. if this happens, check the solenoid wire (yellow? or yellow/black?) from the ign key to the solenoid.

If it blows immediately upon inserting the fuse, check the wire from the fuse to the ign key. It should be red/purple.

If it cranks and then blows after starting, check the purple wire from the ign key to the gauges and motor.

 

[soburke]

Re: 1993 commercial 100 v4 - No power to Motor

Hi Chris,

You nailed it again, the fuse did not blow right when I put the fuse in and, in fact, everything worked great on the motor (trim, etc.) However, as soon as I turned the key but not even cranking the motor the fuse blew.

So one question I have is that wiring harness runs from the ignition key all the way to the engine....so I am not sure how or what to check with the ign wire you mentioned.

For what its worth, the wire where the fuse is located is solid red. running off my solenoid are two red wires (one of which has the fuse) these are at the termination of the hot line from the battery on the top of the solenoid. running from the side are a yellow with red and a solid black line running from separate bolt/terminals on the side of the solenoid. All of these wires disappear within six inches or so into either electrical tape wrapping and or then into the wiring harness. They are not melted or cut or worn.

I can trouble shoot this I just don't know what I am looking for.....

As always, thanks for the guidance...I truly appreciate it.
Stephen

 

[Chris1956]

Re: 1993 commercial 100 v4 - No power to Motor

OK, Lets try something cute. It is likely smart to disconnect the battery, for safety, and remove the burnt fuse. Now put an ohmmeter on the boat side of the fuse holder, and check to ground. You should see a short to ground, when you turn the key. See if the short disappears when the key is in start position. If it does, the short is likely on the purple wire. To confirm, you need to test the resistance of the purple wire at the motor. See if you can find a place to test the purple wire, either on the motor or on the boat dashboard. Verify it is shorted when the key is in the run position.

Now disconnect the purple wire connector at the motor. and recheck the purple wire to ground. If the short exists, and you are testing at the dashboard, the fault is in teh boat harness. Check all the gauges for shorts, and especially the purple wiring to the gauges. If the short is gone from the dashboard, the short is on the motor harness. Verify by testing resistance from motor connector to ground.

If it turns out the short is in the starting circuit, test from motor connector on yellow/red wire to ground, and from boat harness yellow/red wire to ground. One will be shorted.

Disconnect wire at the solenoid, as this device is not a dead short, but a low resistance connection to ground, which could confuse your readings.

 

[daselbee]

Re: 1993 commercial 100 v4 - No power to Motor

Let's try something else cute.

Temporarily wire in place of the fuse a 12 volt auto lamp. When the short exists (turning the key to on) the lamp will glow brightly. Then you can fiddle and fool with the wiring all you want looking for the lamp to go out, without fear of burning any wires up. When the lamp goes out, you have found the area of your short. And you save on fuses.

It is probably on the purple wire as noted by Chris1956.

 

[soburke]

Re: 1993 commercial 100 v4 - No power to Motor

OK, I think this may be our last update but I wanted you both to know how things worked out.

So I went through about 5 fuses, checked all the wires you were referring too and still could not figure out what could be causing the short as they looked good. I was thinking about the my start procedure and when the fuse blows and was at the remote control when I realized and remembered that I had been wiring a Tach pigtail last year.

When I looked at the Tach pig tail I remembered that I was confused on what to do with the Purple wire and thought it had to be wired into the gauge chain that you see in a lot of the graphics...well I could not get into my dash (98 bayliner capri) so I just assumed I could not make it work and taped off that purple wire. But still had the ground and grey wired to the gauge and ground.

I thought I would just see what would happen and took the tach pigtail off the remote and I had no more blown fuses! It was around midnight so I couldn't haul the boat out and try to start it as we live in the burbs. But now that the fuse is not blowing i will likely be on to the next 'problem'.

Additionally I spent some more time on the forum and read all the different posts on Tachs and their wiring and realized that the purple goes to the Key/Ignition, grey to the dial, and black to ground. I pulled off the key/ignition and see the other purple wire and this weekend I will run a line from that ignition post to the purple line on the Tach. Hopefully I won't go through 10 fuses in the process

Thanks to each of you for all the help. And once again I am my own worst enemy; I fear my wake far more then the boats.
Stephen