tac. problem is this right?

[ohio river rat in KY]

ok my tac did not work took it out and it was set on 3 cyl. which i put on 4 because thats what i got 120 mec. now they had it wired to the solenoid post on the starter one of the little postis this were it goes?? now dont you suppose to hook it up to the neg.side of the coil (its points system) but i tried the coil and it pegged it out like it was straight wired to the battery and i tried to hook it up like they had it and nothing. so what do i need to do different? if the tac was bad it would not read at all would it because it works with power. and all it has on it is a neg. post and one marked S on it and the light just pops in the back.

 

[cr2k]

Re: tac. problem is this right?

The post marked S should go to the neg side of the coil (Points ign). the P or power post on the tach should get a purple wire (key switch power) and there is a ground that may just be under one of the mounting bolts. The light should have a blue wire on it.

 

[ohio river rat in KY]

Re: tac. problem is this right?

this is what is got me confused there is no power post its just got the ground post and the S post witch i tried to hook up to the neg.- side of the coil and it pegs it out to 6 grand at idull (like it is wired straight to a power source) could the cylinder switch be bad ? or could the coil be wired wrong because when i got this boat they started restoring it and stoped for some reason and sold it and another person put the motor in, its changed owners like i change my underwear i am the one trying to get it back right again wires was run every where i bet i got 20 feet of extra wire out of it they said the power trim was bad and all it was not grounded so who knows what else is backward or not hooked up??

 

[Alpheus]

Re: tac. problem is this right?

What year is the engine? I may be able to get you the service manual with wiring diagrams...




PS

Is the tach original to the boat/engine?

 

[Silvertip]

Re: tac. problem is this right?

Some old style tachs did indeed have only two connections. If the "S" terminal on the tach had been connected to the "S" terminal on the starter solenoid, that terminal received 12 volts when the key was turned to START. It may then have popped some circuitry inside the tach. The "S" terminal on the tach should go to the ignition coil as that is where the ignition pulses come from that the tach is counting. There are no such pulses on the "S" terminal of the solenoid. That's strictly 12 volts.

 

[ohio river rat in KY]

Re: tac. problem is this right?

What year is the engine? I may be able to get you the service manual with wiring diagrams...




PS

Is the tach original to the boat/engine?

the paper work (title) is 1980. as for the motor ? they told me they put that motor in just going on there word its a 120 mec.4 cyl and the only thing i know for sure is the 4cyl.part.and its got a Chevy starter and alternator on it. the gauges look to be all original to the boat

 

[ohio river rat in KY]

Re: tac. problem is this right?

Some old style tachs did indeed have only two connections. If the "S" terminal on the tach had been connected to the "S" terminal on the starter solenoid, that terminal received 12 volts when the key was turned to START. It may then have popped some circuitry inside the tach. The "S" terminal on the tach should go to the ignition coil as that is where the ignition pulses come from that the tach is counting. There are no such pulses on the "S" terminal of the solenoid. That's strictly 12 volts.

who ever wired this did not know what they was doing or did not care i have no clue why thay wired a tach. to the starter i have found many short outs in it. they had speaker wire run to the lights and raw wire touching or grounding out in all kind of places, like i said before they said the trim did not work and they did not have the ground hooked up and it works find now. its just time comsuming to see if any of it is wire right but better safe than sorry. the fuse is my new best friend

 

[CheapboatKev]

Re: tac. problem is this right?

the paper work (title) is 1980. as for the motor ? they told me they put that motor in just going on there word its a 120 mec.4 cyl and the only thing i know for sure is the 4cyl.part.and its got a Chevy starter and alternator on it. the gauges look to be all original to the boat

Do I read that as automobile parts?

 

[Alpheus]

Re: tac. problem is this right?

Give this a read. It should help...



http://www.4shared.com/document/z_94xkbJ/Mercruiser_Service_Manual_4_19.htm

 

[ohio river rat in KY]

Re: tac. problem is this right?

Do I read that as automobile parts?

the starter looks to be for sure,but the alt. is sealed (for a boat)but it is the same type as the late 80s of a chevy

 

[CheapboatKev]

Re: tac. problem is this right?

the starter looks to be for sure,but the alt. is sealed (for a boat)but it is the same type as the late 80s of a chevy

Yes they look identical...but you have to, ABSOLUTELY HAVE TO HAVE A MARINE RATED STARTER!!! The extra 50 bucks or so over an automobile starter is not worth the explosion hazard.

 

[ohio river rat in KY]

Re: tac. problem is this right?

Give this a read. It should help...



http://www.4shared.com/document/z_94xkbJ/Mercruiser_Service_Manual_4_19.htm

thanks 4 the link it is going to be very very helpful, just browesed throw it and found at least 2 more mess ups that was done wrong. going to hate to see what else is wrong when i take my time.