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H20skeefreek
05-29-2006, 09:43 PM
Today while out on the lake something weird happened. While underway (actually towing a wakeboarder) the boat tried to die. My first reaction was that I'd run out of gas, because that's kinda the way it felt. I restarted and it died a few times. The voltmeter was reading extremely low, around 10 volts and the gauges kept cutting off. Perfect pass kept beeping because it wasn't getting enough voltage. I unplugged PP, and it didn't help the situation much. I was able to get to the ramp but only if I cut everything else electrical off.

When we got the boat on the trailer, I had a battery tester in the truck and tested the battery. It was reading 12.69volts and more cranking amps than it was rated for (just replaced a few weeks ago b/c I noticed the gauge running low, and figured it was time to replace it)! Something wierd is going on!

I noticed that the nut on the back of the alternator that hooks to the orange wire, which If I remember corectly is the charging circuit, was kinda rusty. Could this be the problem? If I want to check the output of the Alternator, where do I hook up the multi-meter? To the orange terminal and ground?

The day before I broke a freakin' throttle cable and now this, this is getting embarrasing.

Hoosier Bob
05-29-2006, 10:09 PM
I doubt that is the problem but it never hurts to go through all connections and clean them up. If the amps were there and volts my guess is it is getting a charge. The alternator also powers the boat while underway. If you said Orange I believe that lead sends power to the boat while the red powers the batery. CheckThe problem may be some electrolosis or corrosion near the ignition. No expert but first thing I would check would be dash and cleaning the connections. :wavey:

H20skeefreek
05-29-2006, 10:14 PM
I'll try cleaning all the connections. everything in the dash is good, all new gauges last year, as well as a new ignition switch. The terminal that is rusty is the big one, so that would be what is powering the boat? That very well may be the problem then.

Where do I check the output of the alternator?

jake
05-30-2006, 08:50 AM
I'm very interested in this as well. I have the same issue, although not as bad as what you experienced. At low idle, my perfect pass is constantly beeping/rebooting and the gauges cut in and out. I replaced my battery assuming it was the issue, but it didn't solve the problem. My voltage gauge reads low, maybe 10-11 volts, but I've been told they can be inaccurate. A mechanic friend checked my alternator and said it is fine, although I'd be interested in knowing how to do that as well. I don't think the alternator is the issue because I had this problem all of last year but the battery always maintained a healthy charge. If I had an alternator problem, wouldn't my battery be going dead?

If I increase RPM above 8-900, the problem goes away. Boat is '93 w/ HO 285 hp 351.

H20skeefreek
05-30-2006, 10:45 AM
sounds like we have about the same problem, though it even died at 22mph. It didn't fully die, but all power dropped, then it started again, just about killed my brother in law.

92 190 PS
05-30-2006, 10:59 AM
I am having the same issue as Jake with my '92. Assume the output from the alternator is fine because once boat is under power volts read OK. Boat is new to me and previous owner put a regular car battery in the boat and not a deep cycle marine battery...I was guessing that was my issue?

H20skeefreek
05-30-2006, 11:01 AM
The chemistry of auto vs. marine batteries in the same. By not putting a deep cycle, it will impede your ability to run accessories for long periods of time w/o the engine running. It shouldn't be a problem. Mine is a dual purpose battery with plenty of cranking amps and plenty of amp hours.

3event
05-30-2006, 11:09 AM
In prior life, on a Merc outboard. Motor would just up and die in the middle of a run, then start right up like nothing was wrong. VERY EMBARRASING on a nice new boat. This went on for 6 years on and off after various shops being unable to diagnose. Replaced various parts and eventually the ECM, but no fix!

FINALLY diagnosed as not fully tightened battery terminals!!!!! After years of pain. Just a momentary loss (fraction of a sec) enough to shut the ECM down. By the time you restart, everything is fine again. But by that time we had had enough, and that's when I bought the MC.

So, always make sure terminals are tight and really clean. What an easy fix it would have been from the start .....

H20skeefreek
05-30-2006, 12:46 PM
FIXED IT!!!! evidently we had knocked a wire loose behind the dash, it was the wire that send juice to the gauges, which supplies juice to the tach, which if it's not powered, screws up everything. I wish there was something to protect those wires, maybe I should build something out of starboard lumber. This is the second time that a similar instance has happened.

H20skeefreek
09-04-2006, 09:01 PM
well, the problem seems to be back, and i've checked all of the connections everywhere.

My tach is very jumpy when the boat is not in gear, and it's worse when the blower or bilge pump are on. It definately seems electrical to me, and I plan to completely re-wire this winter, but I need this thing fixed now. Any ideas?

JIMN, where are you???

cwright
09-04-2006, 09:22 PM
I just solved a host of electrical problems when I discovered one of my daisy chained ground connections had a broken link. Felt loose, looked normal, and finally wearing some cheaters I was able to see a crack and upon closer inpsection realized the tab was actually broke. A drop of solder solved my probelm and about four electrical issues at the same time. Double check your daisy chained connectors, closely.

H20skeefreek
09-06-2006, 07:49 AM
"cheaters"?

I've been thinking ground connection, but don't really know where to start. I've looked and tugged on everything. Maybe some "cheaters" are what I need?

JimN
09-06-2006, 08:08 AM
Cheaters are glasses.

Look at the battery terminals, then inspect every connection along the way to the motor and the dash. Clean the posts and terminals on the alternator and battery. Check the ignition switch for loose screws and bad terminals. Look at and do a wiggle test on the ground wire at the engine block. If the tach is jumping around, go to the distributor and make sure it has a good connection to the block- if there's much resistance, the points or electronic ignition has no ground reference and you won't have consistant or strong spark. Also, check the tach lead and make sure it's not grounding out on the way to the tach. If it does, you won't have spark.

Re: the deep cycle vs cranking battery- in a ski boat, the main job of a battery is to crank the motor, not run accessories. A motor like this needs a lot more current than an outboard and can draw anywhere from 175A to 350A, depending on the type, age and condition of the starter. Yes, there are high reserve cranking batteries but a straight cranking battery is really best and if there are a lot of accessories, a separate deep cycle should be used for them.

H20skeefreek
09-06-2006, 10:03 PM
I have checked every connection for cleanliness and tightness, and all seems good. I checked all of the grounds by connecting a tester to the + side of the battery, then checking each ground. It showed 12.47-12.51volts on every one. I then went back and I've done most of the + connections that should be live, and got the same thing.

When I check the grounds, and I turn the blower or bilge pump on, the voltage starts to drop, this is normal right? If I leave it on it continues to slowy drop 'til I turn it off, the more that are on, the more it drops. If it isn't obvious, this is with the engine off. The boat is in the garage, so running the motor wasn't an option for tonight.

My first thought was to re-do all of the grounds going to a bus bar, then run a dedicated heavy ground wire either back to the battery or to the engine. This would be a large task, and maybe an unneccesary one, what do you think? There is a LOT of daisy chaining going on with grounds, most of them from the factory from the looks of it.

What do you think about the fact that this seems to happen more when the boat is warm? My buddy thinks b/c of that it's a problem with the coil. How do I test the coil.

when you talk about a good connection to the block for the distributor, you mean where it actually physically contacts the block right? Ther shouldn't be a wire should there?

JimN
09-06-2006, 10:12 PM
The ends of the terminals may look clean but there may be corrosion where the wire is crimped. If you can determine the wire gauge to the dash, that may help. If you want to increase the ground wire gauge, abandon the original one.

Re: the daisy chaining- there are a lot of boat manufacturers that do it this way but it generally works well enough. I have seen some with a ground buss, too.

The distributor hold-down needs to make good contact with the base of the distributor and the block. There's generally an O ring to seal the inside of the motor from the outside world.

H20skeefreek
09-07-2006, 05:19 AM
Using my test method from above and adding a wiggle test to each connection will test for internal corrosion correct? Or do you think that I should change out all of the terminals?

What do you think about the warmth/dieing issue? What do you think about it being the coil?

JimN
09-07-2006, 08:08 AM
I would say it's possible for the coil to be the problem but I wouldn't bet the farm on it. How long since the plug wires were changed? I have seen more coil wires cause this kind of thing than bad coils.

cwright
09-07-2006, 10:51 AM
Also, have you had the battery load tested. The blower on should show a small drop in voltage but it should hold. Such a small load contintuing to drop voltage makes me suspect you battery is toast and not capable of taking a load. I don't have strong feelings that this is your problem, but it is an easy test to have done and most battery places will do it for free. May as well rule it out.

JimN
09-07-2006, 11:03 AM
Good point about the battery possibly being toast.

H20skeefreek
09-07-2006, 04:04 PM
This battery is only a few months old, I have a tester in my garage, it is rated at 680 CCA and is putting out over 700 CCA, so I don't think that's the problem.

The plug wires are about a season and a half old. They are HIGH end wires have a lifetime warranty, granted, I don't expect them to last a lifetime, but I would think they'd last a few years.

distributor cap/rotor was replaced at around the same time which was around 50 hrs. ago, they look to be in great shape.

I'm struggling with the heat connection, that has to be a factor.

CaptCurt72
09-07-2006, 06:29 PM
My guess is that you have a wire somewhere that is frayed or a bad crimp. As the electrical system pulls current that connection acts like a high-resistance circuit and the voltage across that junction will be high. The higher the current, the higher the voltage drop. This lowers the voltage at other points along the path. The point where the bad connection is will get hot to the touch, maybe very hot. The only things that should carry much current are the starter, alternator, and a stereo amp. A wire with a poor connection will not show problems until current (pulling a load) is running through it.

With the engine running and everything on, take a digital voltmeter and measure the voltage drop from one point to the next (positive-to-positive or negative-to-negative). When you see more that maybe a few tenths of a volt across a junction, there is a problem in that line. It could either be a ground or a positive wire. I would check from the battery to the end of the circuit, and then start measuring points in between. You can use a long piece of wire to extend the voltmeter’s cables.

The battery voltage with the engine off should be about 12.4vdc, and with the engine running it should be about 14vdc. If the battery voltage does not go up after the engine starts, then the alternator is not charging the battery.

Hope this helps.

H20skeefreek
09-07-2006, 06:37 PM
My guess is that you have a wire somewhere that is frayed or a bad crimp. As the electrical system pulls current that connection acts like a high-resistance circuit and the voltage across that junction will be high. The higher the current, the higher the voltage drop. This lowers the voltage at other points along the path. The point where the bad connection is will get hot to the touch, maybe very hot. The only things that should carry much current are the starter, alternator, and a stereo amp. A wire with a poor connection will not show problems until current (pulling a load) is running through it.

Would this happen as soon as current is ran accross it, or could it take time (like 2.5 sets)?

With the engine running and everything on, take a digital voltmeter and measure the voltage drop from one point to the next (positive-to-positive or negative-to-negative). When you see more that maybe a few tenths of a volt across a junction, there is a problem in that line. It could either be a ground or a positive wire. I would check from the battery to the end of the circuit, and then start measuring points in between. You can use a long piece of wire to extend the voltmeterís cables.

When you say pos to pos and neg to neg, you mean to connect to the terminal at one end of a given wire, then test it as I go down the wire toward the other end?

CaptCurt72
09-07-2006, 06:56 PM
The longer the high current goes across a circuit, the hotter it will get. Just depends on how bad it is. Most could take minutes to hours.

As for testing, yes, test the wire in series to see if there is a drop across one or more connections. If you find a drop, then start searching between thoses two point to isolate the problem. If you measure from positive to negative, then you have to compare that voltage to the voltage at the battery at the same time, and you still would not know if it was a positive or ground wire.

H20skeefreek
09-07-2006, 08:55 PM
Capt,

What I was getting at was: Could the negative effect take 2.5 sets to manifest if this was the problem, or would it be immediately noticeable?

CaptCurt72
09-08-2006, 08:42 AM
Yes it could. It simply depends on how hot it gets as to when the voltage drop become critical. At some point the voltage to critical components such as the ignition will be too low, and the engine will stop running. However, a noticeable voltage drop at the defective point should be evident as soon as the engine is running.

Some old ignition systems have a resistor that reduces the voltage on the coil after the engine is running to prevent the coil from overheating. A coil would take probably 10-30 minutes to really get hot. You can feel the coil after it is running to see if it appears to get hot.

JimN
09-08-2006, 09:06 AM
Actually, the resistor is to keep the points from burning up since they can't handle 12V.

pilot02
09-08-2006, 09:41 AM
I had a similar problem with my 89 tristar. I was getting 12.5 volts at the battery and into the wiring as it enters the dash but only 10 on my voltmeter and my accuski would disengage. Turned out to be the daisy chained connectors behind the dash. I replaced all of the ground wiring behind the dash and eliminated splices with soldered connections. Took a while, but has been worth it.

CaptCurt72
09-08-2006, 05:09 PM
Actually, the resistor is to keep the points from burning up since they can't handle 12V.
Yes, a high voltage across the points would cause them to arc when open. However, The points open and close to allow the coil to charge. Once the points open, the coil (an inductor) wants to maintain a constant current. In order for this to happen, a high voltage (low current) spark is generated that dissipates through the spark plug. The capacitor keeps the voltage across the points low, and thus keeps the spark from jumping back across the points and burning them up.

Take the resistor out and the coil will burn up from too much current when the points are closed. Take the capacitor out and the points will burn up from too much voltage (arcing) when the points are open.

nuckinfutz
09-08-2006, 05:26 PM
I would suggest cleaning the alternator post for starters. then as someone mentioned before, Check your terminals. If you have a weak point of connection to the battery it will not charge correctly. I suspect a voltage regulator or poor connection somewhere.

Some more info;
Your alternator provides votage when your motor is running (hence you can disconnect and remove a battery when the motor is on and it shouldnt die) To test alternator (and or voltage regulator) you can run the motor and increase rpm's(mabey 1200 or so) you should read 14 volts or so at the battery terminal. If it is less, VERY VERY carefully (dont get cought in the pully) test it at the alternator (your orange lead to the positive side of your test meter, and ground to the neg side of the meter). Alot of instruments and accessories are powered from the same source as the alternator/battery charge connection.

JimN
09-08-2006, 05:29 PM
The cap acts as a buffer and, as you said, softens the voltage spikes. The material used for the points is durable enough to work with the resistor and cap but that's about it. Good thing electronic conversion kits were developed.

You can think of it in terms of a spark dissipating if you want but what's really happening is, a magnetic field is set up in the coil primary when the circuit is closed and when the field collapses due to the points opening, the sudden voltage change and corresponding shift in the magnetic field induces a voltage in the coil secondary and this is what causes the arcing at the spark plugs. The increased voltage at the output is due to the ratio of the windings between the coil primary and secondary.

MCPS205
09-08-2006, 05:52 PM
Dont you need to "excite" your alternator before it will start putting out a charge? For example, running it above 2500 rpm.

NeilM
09-08-2006, 07:17 PM
Dont you need to "excite" your alternator before it will start putting out a charge? For example, running it above 2500 rpm.

No need. Alternators are excited (the electronic magnetic field coils are charged) by residual voltage in the battery, which means they will produce current at idle -- that's why they replaced the generators of old..

JimN
09-08-2006, 07:36 PM
MCP- if you look at the post with the purple lead on your alternator, it probably has EXC cast into the case. This is how the field is generated and when the armature spins, it induces alternating current. While an alternator will produce current at idle, the voltage isn't at maximum until higher RPM.

H20skeefreek
09-09-2006, 07:32 AM
OK, so I've gotten no closer on diagnosing this, I'll just continue on my "needle in a haystack" search.

JimN
09-09-2006, 08:19 AM
I don't know if anyone has said anything about this but look on the starter solenoid for a red or orange wire that goes to the main harness. Make sure all connections are clean and tight, then go to the boat plug, which is a black multi-wire plug that makes it possible to install/remove the motor without having to wire/unwire things individually. Make sure the plug is fully engaged and clean.

H20skeefreek
09-09-2006, 08:51 AM
done. done and done.

JimN
09-09-2006, 10:19 AM
OK, have you measured the resistance from the battery negative post to the point where the dash harness connects to the ground wire in the main harness? Do the same for the 12V battery lead on the ignition switch, with the negative cable removed. If you need to extend the test leads, do a self test first, then subtract that from the total resistance. You should have no more than ~.2 ohms. .1ohms is preferable but not realistic.

Brn85ss
09-09-2006, 12:18 PM
Have you checked the Tack to make sure it's not shorting out.

JimN
09-09-2006, 04:31 PM
While the tach would kill the spark, it wouldn't show a low voltage. If the voltage to the coil drops below a certain point, the spark will be too weak or nonexistant and the motor will stop, however.

H20skeefreek
09-10-2006, 08:52 PM
ok, so forget the crap about the jumpy tach, I don't think it's related. I rewired the entire dash. running buss bars for all common grounds and the common 12v power. The jumpy tach and any other gauge issues are GONE.

Boat still loses power when at skiing speeds. It doesn't ever happen on the first set, but it happens at some point after that. It feels like the boat is out of gas, but I've got a full tank. I pulled the pickup out of the tank, clean. Nothing in the fuel pump overflow tube, fuel filter is pretty clean. Not perfect, but not a ton of junk in it. There is NO water in the gas. I had the tank empty and out a few months ago and put in 5 gallons at a time (and turn around an burn most of it) so there is no water.

Interestingly enough, I found 2 loose spark plugs today. I tightened them down and it still happens. The 2 plugs are a little carboned up, but not so bad that it would cause this problem. I ordered a new coil, and when I pick it up on Tuesday, I'll get all new plugs to replace with it. I replaced the distributor cap, but not the rotor, I thought I had a spare with my spare cap, but negatory, it looks great anyway.

JimN
09-10-2006, 10:16 PM
Did you say that you checked the fuel tank vent?

H20skeefreek
09-11-2006, 08:29 AM
no, I did not, I'll check it today.

H20skeefreek
09-11-2006, 09:20 PM
checked it, it's clear.

H20skeefreek
09-17-2006, 08:46 PM
I started a new thread about this problem.

http://www.tmcowners.com/teamtalk/showthread.php?p=243403#post243403

BrianS
09-19-2006, 09:26 PM
Check out this post. I was having what sounds like a similar problem.

http://www.tmcowners.com/teamtalk/showpost.php?p=219605&postcount=10

Ironically, I also have the flaky guage problem on my '93. Voltmeter reads low, Temp guage rises when blower and or nav lights are on etc. I'm going to tear into the dash wiring this winter.