1978 1150

[pfoley]

I just purchased a boat with a 78 merc 1150 on it. The day I looked the boat it started and ran great. "Turn-key" suposedly!<br /><br />Anyway, when I got it home, the trim barely worked and the engine would't turn over. Great! I wiggled all the connections and the trim worked for a minute, but the engines still didn't turn over. All of this reminded me of a dead battery, so I bought a new one. Still, no trim, no engine. I then replaced the old battery terminals. The trim moved an inch and then lost power as if the battery had died. It clicked for a second then nothing. It seems like neither the trim motor nor the engine is getting enough juice to operate but I don't know why? Any suggestions?

 

[Clams Canino]

Re: 1978 1150

Just follow the power. Try the power plug on the side of the motor (re-insert), then go inside and try where the big leads connect etc etc.<br /><br />You prolly have a loose connection somewhere is all.<br /><br />-W

 

[pfoley]

Re: 1978 1150

Thanks Clams! This engine has the trim motor located in the boat. If the power plug on the side of the motor (didn't know it had a power plug) had come unplugged would that affect the function of the trim or just the starting of the engine? It looks like the trim motors get their power directly from the battery, but I'm having trouble with them too.

 

[jameservin]

Re: 1978 1150

Does your boat have the trim only at the control or is there also a trim switch at the back? My 1150 has both. One at back is a aftermarket thing wired to trim motor inside boat. <br /><br />As clams said its prob loose or corroded wire.

 

[tashasdaddy]

Re: 1978 1150

check the condition of the battery cables. one small nick in the cable will allow moisture to get in and corrode the wires, and you never no it till it doesn't work.

 

[pfoley]

Re: 1978 1150

Thank you all. I messed with the plug on the side of the motor (unplugged it then re-inserted it) and the trim motor worked great at first, then started to slow down a bit. I tried the ignition. It was getting power finally, but not enough to turn over. Then I noticed a small fire coming from the wires that connected to the trim sylenoid (sp?), so I quickly disconnected the battery! Upon further inspection, the insulation on the two wires was so rotted, it was turning to dust at I seperated them. I guess they were shorting themselves out. I taped them up the best I could. I reconnected everything. The trim was a little slow and there was little power getting to the starter. I'm guessing that the short was draining the battery (hopefully), so I put it back on the charger last night.<br /><br />Is there a new harness I could buy that would replace those rotted trim wires, or should I just use regular Home Depot wire? I'm not sure, but I think they run from the remote trim buttons to the sylinoid. What guage wire do you reccomend?<br /><br />Is it possible to buy the plug/harness that plugs into the side of the engine too? It looks like it could use some work too.<br /><br />Thanks again for all the help.

 

[Clams Canino]

Re: 1978 1150

If the trim motor is mounted in the boat your best bet is to buy the wire and connectors and make it yourself new - solder the connectors don't just crimp them. If you need an internal wire harness for the outboard they are usually on Ebay real cheap - search on "mercury internal wire harness"<br /><br />-W

 

[pfoley]

Re: 1978 1150

Thanks Clams! Would you know an appropriate guage of wire to use?<br /><br />Also, the internal harness has been replaced. The external one is original and looks worn. Where do I get one?<br /><br />Thanks.

 

[Texasmark]

Re: 1978 1150

Don't know on the current requirement of the trim motor nor your distance. The motor is not that large considering the size of the trim unit which also includes the hydraulics. I'd bet it wouldn't see 15 amperes.that's 120 watts, 1/5 hp considering losses.<br /><br />12 AWG is not too heavy and easily carries 20 amperes to 50 foot of length continuously. Trimming your engine is very very intermittent operation so you could handle as much as 30 amps if needed and still not get the wire hot which is the metric for determining wire size.....along with insulation temperature rating.<br />Problem is interconnect. You need stranded wire and terminals for good connections. Problem is connecting the wire to the terminals. Best to crimp and solder, but sometimes crimpers and large soldering irons are hard to find.<br /><br />Then when finished, a good wrapping with heat shrink or quality electrical tape at the interface between the connector shell and wire insulation will keep the water out.<br /><br />That's my best shot and would do it personally in a heartbeat if I were where you are. <br /><br />On electrical connections: Clean, bright (shiny), tight.<br /><br />Mark

 

[Texasmark]

Re: 1978 1150

Er ah at 15 amps watts should be 180, not 120. Sorry.<br /><br />Mark

 

[Texasmark]

Re: 1978 1150

One more thing. When you worked your connector you said things improved then went bad again. You just told yourself the connections were dirty and you cleaned them......just didn't finish the job. Not easy to clean out a connector like that. Connectors corrode (green gungy looking film) and that insulates the metal which significantly reduces the ability to transmit power (amperage).<br /><br />Thinking about how I could clean the connector. Would probably use alcohol, compressed air and just make and brake the connector a dozen times, come in with the alcohol and wash both sides out, blow out with air and go back for another dozen makes and brakes. Do this till you can see the connections shiny.<br /><br />Course you could always buy new wiring harnesses....yeah right!<br /><br />Best I can do.<br /><br />Mark

 

[tashasdaddy]

Re: 1978 1150

this is why is said check the battery cables. my gas can had damaged one. when i found it, the were only 3 strands still connected inside the insultation. thus not enough power.

 

[pfoley]

Re: 1978 1150

I was thinking about a new harness until I saw all the connections I'd have to make. I will try to clean what I have, and double check the battery cable. I'll let you know.<br /><br />Thanks again

 

[pfoley]

Re: 1978 1150

Another question for Texasmark. Why do I need stranded wire for the trim motor? Is that so it can take a beating better?

 

[Clams Canino]

Re: 1978 1150

Yes, better flex.<br /><br />-W

 

[Texasmark]

Re: 1978 1150

Stranded wire attaches better to the terminals in addition to flexing as mentioned by the other contributors. Normally stranded is used for things like extension cords that flex all the time and single conductor is used for things like NM (Nomex) house wiring that never moves.<br /><br />Butttttttttttttt with that said, your concern is being able to get attached to your terminals and multistrand does a better job than a single conductor.....It will work, but your crimp and solder need to be good for it to hold up in a vibration environment.<br /><br />Mark

 

[pfoley]

Re: 1978 1150

Thanks for everyone's help. I got her running last night!! I still need to replace the wiring to the trim switch, and the external wire harness though. Where do I get a harness?

 

[Texasmark]

Re: 1978 1150

With the excellent luck I have had, product, service, shipping, performance, try iboats!!!!<br /><br />Mark, <br /><br />Not an employee, just a satisfied customer.<br /><br />Mark

 

[Clams Canino]

Re: 1978 1150

If you can't find an external harness I know a pretty good source for 22' aftermaket ones that fit like they grew there.<br /><br />-W

 

[pfoley]

Re: 1978 1150

I would love an aftermarket harness that fits like it grew there!! My boat is 16' long, will a 22' harness work well? <br /><br />Thanks again.