major electrical short?

oldblumerc

Seaman
Joined
May 29, 2003
Messages
53
ok im getting my 74 merc back into shape for this year and i get the new battery installed connect it up and my main circuit breaker keeps tripping and reseting, at the same time all my guages top out anyone know what could be doing this. my trim pump still works but my starter wont turn over and its a 74 merc 140
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: major electrical short?

The trim should be on it own cables which is why its working<br /><br />Any chance you mixed up the + and - ? after that with the battery disconnected<br /><br />I would break out the OHM meter and see if the postive cable has got a connection to ground causeing a dead short and triping the breaker<br /><br />If it does you need to start unhooking things till you find the bad part<br /><br />tommays
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: major electrical short?

Be careful using an ohm meter on a circuit that might have voltage on it. You'll either hatch the meter or pop an internal fuse if it has one.
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: major electrical short?

P5250012.jpg
<br /><br /><br />Make one of these from a headlight globe - it's simple and cheap.<br /><br />Disconnect the '-' terminal of the battery, connect one of the test leads to the batt '-', the other test lead to the disconnected battery cable.<br /><br />If you have a short the globe will illuminate, the brighter the light, the bigger the short. Start wriggling wires - turning switches on & off - etc etc. When the light goes out, you've found your short.<br /><br />You CANNOT cause any damage testing this way.
 
Top