electrical trouble shooting help pleaase (82 - ish 80 hp)

[lostintexas]

82 merc 80 horse I picked up last fall and I am trying to make run this summer. If you need more details or pics , let me know. I will get back to you pretty quick. I do have a manual and can use a volt meter/ soldering iron. I am a electronic tech, so if you need to get down and dirty, feel free. <br /><br /><br />I took the boat to the lake to see if i could put it in the water and just give it a spring time wake up. I have a couple of questions.<br /><br />The motor ran fine in my front yard, although it did miss every once in a while.<br /><br />First - I found a couple of wires that seem to have burnt the insulation off of them. Is this a common problem or is there something I need to look for? I plan to just replace the wires and connectors with parts from autozone/napa. It ran with the burnt insulation, so if I replace the wires, no harm done right?<br /><br />Second, Once the boat was off the trailer. It did start and I backed the boat off the trailer. now the Starter solonoid will not fire. I have 12.7 volts off the battery and that never changes. On the wire from the solonoid to the ignition switch(hot), when i turn the key to the start position, i now loose the 12v as long as the key is in the start position ( this is the hot side of the ignition). The the signal line to the solonoid never changes due to a loss of 12v on the hot side. I am thinking I have a bad connection/broken wire in the harness. do you agree or is there something else i am not looking at?<br /><br />i just replaced the solonoid and the ignition switch. These parts are not known good but new none the less. i have no way to test the parts other than when i replaced them the symptom did not change.<br /><br />third - thanks for the help. i keep looking at the schematic and its not that complicated, i am just wondering why i keep loosing 12v on the hot side?

 

[Laddies]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

You have a bad connection in the system or a dirty one probablely the plug in or the ign. switch could be bad

 

[lostintexas]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

I just jumped the solonoid, so it almost has to be. it will crank if i jump the solonoid and the solonoid will fire if i disconnect the starter?

 

[rodbolt]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

as an electronics tech try to talk by terminals. S terminal, load terminal, and such.<br /> was your last sentance a statement or a question. its some what confusing. I was trained as an electronics tech for uncle sammy. soI can helpya but I need to know how many cylinders and if it has a 10 pin round connector under the hoodor does the ign harness plug into the side.<br /> maybe talk about wire colors here and there. do you have a service manual for it yet ? <br /> does it have a distributor or seperate ign coils for each cyl. its all basic 12v DC for starting and charging. if your solinoid fires its bad. solinoids are just magnetic contactors or electro-mechanical switchs. no fire in them.

 

[lostintexas]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

was your last sentance a statement or a question.<br />

just information, i find the more i provide, the more help i get. <br /><br /><br />

I was trained as an electronics tech for uncle sammy.<br />

thank you for your service to our country, i am thankfull to you. god bless!<br /><br />

soI can helpya but I need to know how many cylinders and if it has a 10 pin round connector under the hoodor does the ign harness plug into the side.<br />

4 cylinder.<br /><br /> there is no connector, it is wired from the helm to the motor. the "B" on the back of the ignition switch is the hot side, the "S" on the back of the ignition switch is the signal(solonoid) side.<br /><br /><br />

<br />maybe talk about wire colors here and there. do you have a service manual for it yet ? <br />

yes i have a manual, from clymer. wite colors are :<br /><br />hot = solid red<br />signal = yellow with red stripe<br />

<br />does it have a distributor or seperate ign coils for each cyl.

each cylinder has its own coil.<br /><br />

<br /> its all basic 12v DC for starting and charging. if your solinoid fires its bad. solinoids are just magnetic contactors or electro-mechanical switchs. no fire in them.<br />

i know, thats what drives me nuts, by saying fire, i mean to activate said device. i get the funny though.<br /><br />thanks for the help, very much appreciated.

 

[lostintexas]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

I wish I could edit that last post. It looks like a two year old wrote it. <br /><br />forgive me please.

 

[rodbolt]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

hahaha<br /> thats ok I usually write like that as well. sounds like someone has jury rigged some wiring. when the key switch is in the start position current flows from the 12v+ tap, you say yours is now at the 12+ side of the start solinoid, through a 20 amp fuse(if its still there) to the keyswitch. from the key switch to the S terminal on the start solinoid. from the S terminal current will flow though the contactor windings to ground. its either an internal ground through the solinoid mount or an external ground lead from the ground post to the block. when the solinoid contacts close current flows from the 12v+ battery post to the solinoid, across the solinoid contacts to the load side of the solinoid, from the load side through a cable to the starter + post. the starter is a standard 4 brush permmanant mag 12 DC Motor. if any place in the system has low current/high resistance its easy to find by either checking voltage at the component of testing voltage drop across the component. no voltage drop acrossed any component may exceed .7 volts with less than a 1 volt drop from the battery to the starter.<br /> hope that helps.

 

[lostintexas]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

time to go back to school. <br /><br />when troubleshooting electrical problems it is sometimes not a safe assumption that the battery is a good ground. especially when the other end is loose on the motor.<br /><br />i feel like an idiot. all day yesterday and 2 hours today. all for not checking a ground strap.<br /><br />thanks for the help and letting me bounce ideas off of you. was just loose enouph to loose ground when i put a heavy load( such as the starter ) on it.

 

[rodbolt]

Re: electrical trouble shooting help pleaase (82 - ish 80 hp)

happens all the time. at least its a cheap fix