Need Electrical Help Please....

[RB in NM]

I have a reoccurring electrical gremlin that I can not find the cause of it………….
Here’s the poop : 1998 Allison XB-2003 with a 98 Merc Pro Max,,, A while back I had the same thing happen, the ignition power would go dead, from key to motor. I cleaned the grounds, verified the circuit breaker was good, pulled all harness plugs and spread connectors to ensure good contact, replaced the 20 amp fuse and inline connectors, etc. After doing all of the above, still no juice at the key switch…….. The next day, I began to attack the problem again, and BINGO,,, there was power there !!!

All was well, like something had reset itself, similar to what a circuit beaker would do.

Yesterday, I cleaned the boat up as I had not used it since the gremlin surfaced. I decided I would see if I could duplicate the issue again. Fired her up on the trailer in the water, adjusted throttle a bit, all was well. Took it off down the river, ran fine, got in an idle zone near my brothers place, while at idle, I felt a ‘bump’ in the motor like it had an interruption to the electrical, then notice my GPS speedo had no juice,,,,, turned key off the reset the speedo, and no juice again……..

Paddled to Brothers, tied up, had a cold one, went and retrieved my truck and trailer, went to load the boat onto the trailer and found I had juice back to the key switch, speedo, etc.. It’s almost as if something is heating up, then shutting of the juice….

Any ideas or suggestions ? ? Would a faulty switchbox do this ?

Appreciate any feedback !

Thanks, Russ

[Jeff_G]

Sounds like a bad ignition switch. Do you lose power to other accessories? I would recommend putting the GPS on a separate circuit and only running the gages off the key switch.

[flabum1017]

It could also be a bad wire in the harness somewhere, a bad crimp connection, poor battery connections, a bad battery cable feeding the motor, key switch (as mentioned), bad harness connection at the motor etc.....

Best way to start is to make sure the battery connections are clean and tight... Check ALL the grounds and crimp connections on the grounds. Next I would do a wiggle check: turn the key on and start wiggling the connections, harnesses etc until you find something that makes the gauges jump around. You can hook up a light bulb to the ignition power for easy visual confirmation. don't forget to wiggle the keyswitch and key too. Also, some people like to use a 4 terminal kill switch and wire the power back to the motor through it.... this could also be a problem so wiggle that too. Check the battery cables feeding the engine, look for buldges in the cable that would indicate internal corrosion.

[RB in NM]

Thanks for the suggestions and help on this guys,,, it's got me stumped pretty good.

Jeff, I will take your advice on the seperate circuit once I get this thing figgered out. And Yes, there is power to trim, hydl plate, guage back lights, other dash located switches,,, just nothing to the key /ignition.


Flabum, I reckon I better get used to tight spaces and standing on my head, as most of the wiring is tucked tightly in the rear side compartments.
I have checked dang near every connection I could put my hands on, thought I had it whupped once already.

Appreciate yer help guys,

Russ