TeamTalk

TeamTalk (http://www.mastercraft.com/teamtalk/index.php)
-   Electrical (http://www.mastercraft.com/teamtalk/forumdisplay.php?f=23)
-   -   Hmmm. Alt problems? difficult hot start on occasion (http://www.mastercraft.com/teamtalk/showthread.php?t=51737)

strad 11-19-2012 07:39 PM

Hmmm. Alt problems? difficult hot start on occasion
 
84 351 PCM. Actually it's only happened once, but mid-late November, no other boats in sight, and you turn it off and it goes whump when you try to restart, it gets your attention lol. It did start after I turned the key again, but that is not ok behavior for a watersports boat. Needs to start every time, hot or cold. It did not sound like a starter issue but more like an insufficient juice issue. Boat is not overheating according to gauge btw. It is right at 155-160 degrees.

I have not checked voltage output at higher rpm, but I know at idle speed it's barely better than battery voltage (about 13.1 edit: actually it started at about 12.8, and after I had the tester on it for about 30 seconds it was up to 13.1, which is where it stabilized). ammeter reads just a needle or two to the right of zero at all times, regardless of load. I do not know if that's normal or if the gauge is actually working. I know on my cars, they do 14 or better volts at idle -- no idea on amps

The alt that is in the boat appears to have an external regulator mounted to the back of it -- looks like a rectangular box -- not something I'm familiar with seeing. I guess I could take it to the store to have them test it but what do I tell them? is it a reverse rotation or anything else special besides being a marine alternator? I also looked at skidim and it looks like they're selling internal regulator alts as replacements now . . . so what they are selling looks different than what I have.

homer12 11-20-2012 04:39 PM

You sure it's alternator? Have you looked at battery condition? Also, grounds in good condition? I had a hot start issue earlier this year. Had my battery checked. Thought it was a starter going bad. Had continuity in my ground at the engine block, but problem was in battery leads. They looked in good shape, but had built up resistance I think from internal corrosion. Cut them off and changed them and no more problems!

strad 11-20-2012 06:02 PM

Well I don't know how old the starter is, but based on cosmetic condition it can't be very old. Dunno about cables and wires. Will have to check that out.

jakethebt 11-20-2012 09:51 PM

Check all connections very well. The marine environment is really nasty for corrosion. Not just rust, but the electrical terminals seem to get nasty quickly. Also, on some of the MCs a bit newer than what you have, maybe mid 90s were famous for the ground wire breaking off the back of the alt. I was reading low voltage earlier this spring and thought I had a weak alt. Went to check it and the ground wire broke off in my hand.

Also... some on here believe that rebuilding is better than new. Search for it if you want to find the debate. I was going to rebuild because it was cheaper, faster and local. Also I was going to "the little guy" which makes you feel pretty good too. Not that I don't love SkiDIM.

Also, just to be safe, if you are looking to rebuild or new, remember these marine alts are not interchangeable with auto alts. Use an auto alt and your boat may go boom.

strad 11-20-2012 10:38 PM

Yeah I know about the go boom part lol. Funny I was just explaining the blower's purpose and when to use it to my wife last weekend--she was flabbergasted to learn about the go boom possibility lol.

jakethebt 11-20-2012 11:28 PM

I just replaced a blower hose that had a hole in it for that same concern...

I am kind or interested in what you find so be sure to post back if you find a solution. I was more than happy to find a broken ground wire. Cheapest and fastest fix possible!

strad 11-23-2012 01:01 PM

Well I didn't check resistance on the cable yet but I did determine that there is no voltage drop between the battery and the other end of the pos cable. Electrics is kind of a black art to me lol.

Jorski 11-26-2012 05:14 PM

Quote:

Check all connections very well. The marine environment is really nasty for corrosion. Not just rust, but the electrical terminals seem to get nasty quickly.

This is really good advice. I had a similar problem last summer and my positive cable end was completely corroded, while my negative was perfect. There can be a lot of moisture in a boat.

Check everything before you start replacing things.

strad 11-30-2012 06:44 PM

Well the cable ends aren't as shiny and clean as they could be (although not bad) so I'll work on that. It is not a charging issue I don't think. Battery is fully charged whenever I check it.

milkmania 11-30-2012 06:55 PM

Quote:

Originally Posted by strad (Post 891646)
Yeah I know about the go boom part lol. Funny I was just explaining the blower's purpose and when to use it to my wife last weekend--she was flabbergasted to learn about the go boom possibility lol.


a good explanation is that gas vapor is heavier than air, it goes toward the ground....

well, in a car or truck... it's open underneath, but in a boat it's not. Therefore gas vapors can build up:(


All times are GMT -4. The time now is 10:18 AM.