OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

[Challenger84]

My engine is an 88' omc gm 305 5.0L v8 w/ cobra out-drive.
So today I took off my new starter to readjust it.
Got new bolts for it and reinstalled starter.
Changed the oil and I was ready to take her out for the first time!
BAD news..

My friend that was helping me installed the battery cables on the WRONG terminals!!

neg to pos.
pos to neg

He said there were sparks coming off the terminals of the battery when he did this.(after I tried to crank the engine over)
I tried to crank the engine over while the cables were switched and NOTHING happened.
I took another look at the battery connection and noticed it on backwards!
Switch it back to the correct terminals try to crank it up and Nadda!!

I tested with a test light to see if the starter was getting power and ground ,it is.
My dash doesn't light up as well when I turn the key.
It seems that nothing is getting power.
My trim works though.It goes up and down.
My blower and bilge pump doesn't get any power as well.
My question is there a fuse or something that might be blown due to incorrect battery connection?
Does anyone have any suggestions on what it might be?
All the hard work put into the boat and today was my scheduled day for the first splash off. This really sucks.
I know it's not his fault.
It's all my fault that I didn't double check the connection and maybe I should have did it myself..

Thanks for looking. and all the help.
-Cheers
Andy

 

[chaparall villain 2]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

check to see if somewhere back around or on the engine there is a reset button .... most engines have a red button on a plate that will kick out to prevent electrical problems . also check to see if you have fuses for starter switch at dash most have safety faults that will blow before causing a fire so i would troubleshoot with the battery connected right to the starter switch in the off and on position most of the time the dash lights are also wired into the starter switch to come on when the boat is started ...... good luck

 

[john744]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

I'd check your battery first. Disconnect the terminals and use a VOLT meter or MULTI-Meter set for DC Voltage. A light has limited useful applications. The VOLT Meter will tell you much more. All batteries contains cells wich generally produce 2 volts each (there are exceptions). Your typical 12 car or boat battery actually contains 6 cells, each producing 2 volts, but wired in series, produces 12 volts. If you get a reading around 12 volts +/- 1 volt, that's good. If however you get a reading of 10, 8, 6, 4, 2 or 0, suspect a bad cell, and replace the battery. Depending on the type (construction) of your battery, your reversed cables event may have damaged a cell (click here) .
If the battery reads 12 volts, look for fusible links in addition to "red button" reset devices.

Keep us posted

 

[solar7647]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

Sounds like your fuse blew. That engine has two 50A fuses. Follow the red wires from the Soloniod the starter is hooked up to. There should be three comeing from the same termanal on the solonoid, two have a fuse in-line with them the third goes to the battery. One or both are probly blown. It is a good place to start.

 

[Challenger84]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

Wow thanks for all the help guys!!
I really appreciate it!
I followed the red wires per the diagram that was posted up and found the two fuses.
I saw that one was blown.
The weird thing is that one is a 40 amp fuse ad the other is a 50 amp.
Should they both be 50 amps?
Did the original owner put in a 40 instead of a 50 amp?

BTW The motor starts right up now.
I will be taking her on a sea trial hopefully this weekend!

Thanks again you guys are life savers!!

 

[solar7647]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

That diagram is from the book, it says 50A fuse, I say put in a 50A fuse. Smaller wont cause an issue but will blow sooner in a situation of a short as you have well found out. I am not saying a 50A wouldnt have blown in that situation but it just would have taken more to do it.

 

[Challenger84]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

So your saying it wouldn't cause any issues running with the 40amp ?
I just bought a pack of 40 amps and a pack 0f 50 amp fuses and if it's okay to use the 40 amp then I'll just keep it in there for now.
Thanksfor all the help

 

[solar7647]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

No a lower fuse wont cause any issue, just blow sooner and that just addes more protection to the devices down stream that is until you get to the point that the fuse is too small and blow all the time.

 

[Challenger84]

Re: OMC gm 5.0 won't crank had to cancel sea trial... PLEASE HELP...

Thanks that's what I was thinking.
If it does start blowing all the time I'll go ahead and put in the 50amp.
Not too hard to do since it's right on top of the engine and I know where it is now.
I'll update this thread later on with my results.