Electrical -- what to look for? (kinda long)

[Bob Ware]

Went to try to find some flounder yesterday after work and all was well. Boat runs fine and caught a few fish. Around 8:00 we crank up to head back to the house. Well, the Coasties were in the channel last night boarding all the boats who came through -- primarily inspection/boarding training for some new troops. Good job guys.
At any rate, just after we got the anchor up and underway I noticed that the tach wasn't working. All other gauges working fine -- ammeter(good charging rate), water pressure, etc. When the CG boarded I turned on the spreader lights to make things easy and after about five minutes they flickered off for about a second then back on with no further problems. After exiting the channel I goosed it for the run across the lake and everything is working now -- including tach. Reach no wake zone and the tach quits again, as does the ammeter but other gauges working fine --- I see a pattern here. Get to the ramp and load her on the trailer but when I go to raise the motor -- tilt/trim doesn't work so we stop at the top of the ramp and do the manual raise thing. Get to the house and put on the muffs to flush and dead. No ignition function at all. All other electrical stuff still working just fine.
It was late when we got home so haven't looked at anything yet but did notice the smell of burned/melted rubber so I'm assuming something either shorted or overloaded in the ignition circuitry.
Any suggestions on where to begin the search for the culprit?

Many thanks......
Bob


Modified by Bob Ware at 4:58 PM 10/14/2005

[THE WITCHDOCTOR]

I guess the first thing we need is year and model of motor....

[Bob Ware]

Ya know.....that just might help

1987 Johnson 225.

[JR250SHO]

Check the voltage regulator.

[SEAHORSE]

Are there wing nuts on the battery terminals or are there hex nuts?

[Bob Ware]

Wing nuts. Tightened with a pair of channel locks.
Giving this more thought today, might I have overloaded the main wiring by leaving the spreader lights on for the 15 minutes or so? Not sure of the amp draw on those lights but it seemed odd that the lights went out for a second or two then came back on.

[Bob Ware]

One problem solved but still more to go. The fuse between the switch and solenoid was blown which caused the 'not starting' condition.
Now I have to track down the culprit which controls the tilt/trim motor, tach and ammeter/voltmeter.

[Bob Ware]

More progress but puzzling. The ammeter/voltmeter is now functioning as is the tilt/trim and the tach worked for 30 seconds or so. I really didn't do anything other than retighten one of the power packs and poked around under the console to see if there were any fuses blown or wires melted.
The tach failed when I hit the tilt/trim switch which leads me to believe there is either a common point between the tilt/trim switch or the tilt/trim is drawing too much power and blowing something in the circuit.

[RUSTY63]

I think the first thing I would do is check the condition of the battery and replace the wing nuts with nylon lock nuts.

[Bob Ware]

I'll get the batteries checked tomorrow but in the meantime I put the nylon lock nuts on and tried both batteries with same results. Engine is running fine and everything now works except the tach.
Any suggested tests if the batteries check out ok?

Thanks a bunch.
Bob

[Bob Ware]

Just returned from having the batteries load tested/checked. Both are good.

Something I noticed this evening is when I crank the engine the tach shows a reading of about 4 hundred RPM while cranking then falls back to zero when the engine starts.

I've check all the connections I can locate as well as grounds which appear to be associated with the ignition. Is it time to consider the rectifier as the culprit here?

Thanks........Bob

[RUSTY63]

Can you get a tach to hook up and check, it may be a bad tach.

[Bob Ware]

That's certainly worth a try. I'll call around tomorrow to see if I can locate one.
If'n I can't get this figger out before Friday evening I may have to run without the tach cuz I'll be in deep doodoo if we can't fish on Saturday. I've already missed the first round of the NLCS and looks like I'll miss tonight as well trying to get this fixed.

Go Astros!!!

[RUSTY63]

You can check the output to the tach with a volt meter, motor at idle (with water of course) hook red meter lead to gray wire and black meter lead to black wire at the back of the tach, you should get 9 volts, if so the tach is bad.

[Bob Ware]

Thanks Rusty........I'll give it a shot. I know ALL about running without water.

[Bob Ware]

Ran the test and have less than one volt.

[RUSTY63]

Sounds like the rectifier/regulator, you can check it by removing the pack and do the same test at the terminal strip, do not hold the test leads, clip them on and remove your hands because FLYWHEELS EAT FLESH, if you still have 1 volt replace the replace the rectifier/regulator.

Be sure you reattach the power pack ground before you start the motor.

[JR250SHO]

Another quick check for the rectifier/regulator is you'll only be getting 12 (or less) volts on the volt gauge. If its working your volt gauge should be reading around 14 volts. Sounds like a bad one to me.

[Bob Ware]

Thanks for the tips guys. I put it in the boat shed and locked her up last night without running the test at the rectifier --- managed to get approval to watch the Astros win instead.
I'll run the test early this afternoon and if that's the problem (sounds like it is) hopefully I can get a new one installed today.

[Bob Ware]

Tried to update the 'subject' but I guess it can't be done or I just ain't figured it out.

At any rate, the rectifier was the problem.
And can you say obvious? When I pulled the power pack off it was VERY obvious where the problem was. The rectifier was melted big time. Appears something shorted inside and fried things. The purple wire was completely melted on the inside such that it was hanging loose.

I should know to always look for the obvious first. Could have saved a bunch of searching and frustration.

Thanks for the help guys you got me to the right place.