Fried out Voltage Regulator

[Hotpuppy]

I too have a Volvo MD6a.

One thing you can do to test:

With the engine running turn the key to "off". If the engine is having trouble with "overcharging" this will immediately "unload" the engine and cause the idle to smooth out tremendously.

On the other hand, you can use a 3 wire style AC Delco alternator to replace that evil Bosch POS. Autozone carries them for about $50 to $80 depending on the amps.

My alternator tensioner broke and I found a turnbuckle worked just fine in it's place and was much easier to adjust. It was ALOT cheaper then the volvo parts place wanted.

[scurvy]

Originally Posted by Hotpuppy

I too have a Volvo MD6a.
With the engine running turn the key to "off". If the engine is having trouble with "overcharging" this will immediately "unload" the engine and cause the idle to smooth out tremendously.

Thanks Hotpuppy!

1. I can only get the engine started with the hand crank currently.

2. I always thought that turning the engine off with the key instead of the kill switch is a BIG "no-no" (unless I am missing the point?)

Chris

[hellosailor]

"One thing you can do to test:

With the engine running turn the key to "off". "

Chris-
NO! EMPHATICALLY NO! NEVER!
Turning the engine off while the alternator is on and running, CAN AND WILL IMMEDIATELY BURN OUT A SUBSTANTIAL NUMBER OF ALTERNATORS.

Not all of them, but most of them. The exceptions to "NEVER": Unless you know for a fact that a ZapStop has been installed on your alternator, or that your alternator has internal protection, ALWAYS kill the engine before shutting the key (which is disconnecting the electrical circuits). And on one boat, I was told "don't worry there's a zapstop under that tape" behind the alternator. Well, yes, there was. Improperly installed under old electrical tape with no supports--so both leads had actually BROKEN OFF from vibration, leaving the zapstop perfectly useless, disconnected at both ends. But the owner knew a $hop had installed one for him.

There's no telling who wired a boat up, or how. A one-wire alternator system is primitive and obsolete--but a three-wire system works properly only when one wire is connected to the battery, for voltage sense feedback. If you have two banks and you don't switch that wire when you switch banks--you're going to have a voltage problem. And if you "tie back" the sense lead directly to the output, as some folks do, you're simply going to defeat it.

Either way...An MD6A or other Volvo installation should come with manuals, and if you don't have them they are available on the web. On a Throughly Used Boat you need to check the wiring diagram versus what is really on your boat. This is a RFPITA but at the same time--the only way to make sure all the wires really are there, are in good working order, etc. Then you'll know what you have, and you can figure out what you want to do about/with it.

[scurvy]

Originally Posted by hellosailor

"One thing you can do to test:

With the engine running turn the key to "off". "

Chris-
NO! EMPHATICALLY NO! NEVER!
Turning the engine off while the alternator is on and running, CAN AND WILL IMMEDIATELY BURN OUT A SUBSTANTIAL NUMBER OF ALTERNATORS.

Not all of them, but most of them. The exceptions to "NEVER": Unless you know for a fact that a ZapStop has been installed on your alternator, or that your alternator has internal protection, ALWAYS kill the engine before shutting the key (which is disconnecting the electrical circuits).

No worries Hellosailor! I wouldn't ever do this I was just asking clarification

I replaced the voltage regulator with a used "original" Bosch regulator/relay, and when I turned over the key...I was met with the same sound (chatter in the box)!

will yank the battery again and have it charged and tested and see if that helps. Will also go through to see if the ground is bad, and check all leads to the starter motor and alternator. I cleaned all contacts to the new regulator, so that end should be good. Hoping it is just a drawn down battery. If so, then the next thing I need to do is start tracing back to see where the sink is in the system...(sounds like fun huh???)

Thanks
Chris

[Gummy]

Jbrock, could you contact me via e-mail? I need an exhaust manifold for my MD6A. Is yours in good shape? Mine corroded inside and blocked up then broke while I was cleaning it.(I bought the boat last month, the corrosion was not my fault)
Rod
email to rodspake (at sign then) usa.net

[WuWei]

We had a similar problem with our old Volvo MD7A. We had old girl in idle and returned from visiting another boat at our marina to a cloud of smoke and that awful smell of bruning rubber. The hubby had a spare (we had a massive inventory of spare parts he had bought on ebay), and this immediately corrected the problem. He said it is similar to a car- they just go bad and can be rebuilt. We had no problems with the old Volvo after that, but still ended up repowering with a Beta engine (the old Volvo, while a good engine, really needed a rebuild...) You should always keep a spare alternator, impeller, starter, belts, thermostat, etc. onboard.

Good luck and I hope everyhting turns out for the best!

Chris
US 30' Wu-Wei
http://www.diysailor.com

[Lancer28]

EDIT: REPOST, i'M A RETARD

[erps]

Someone wrote:

Chris-
NO! EMPHATICALLY NO! NEVER!
Turning the engine off while the alternator is on and running, CAN AND WILL IMMEDIATELY BURN OUT A SUBSTANTIAL NUMBER OF ALTERNATORS.
------------------------------------------------------

My experience is contrary to this warning. While turning off the key might toast an alternator, I think it's the exception and not the rule. Turning off the battery while the engine is running is very likely to toast your alternator while turning off your key de-energizes the alternator by turning off the current to the alternator field circuit (at least that's been my experience with our last three boats and every car I've every owned.)

[hellosailor]

Ray-
There are all sorts of circuits out there. Shutting the battery switch is usually way deadlier than shutting the key--but since you never know what else is tied to the key by a relay, or how the alternator design will handle a key disconnect, the best generic advice is still
DANGER WILL ROBINSON! DANGER! DANGER!

There are many different alternator/regulator designs, different options, different installations. The only generally safe way to operate the electrical system, if you do not know the specifics of that system, is the traditional:
1-Batteries on
2-Switch on
3-Engine running
4-Kill engine
5-Kill key and/or battery switch.

Hey, someone wins almost every lottery pool and casino table. That's great--but it just doesn't work all the time for all the players.

Lancer-
On replacing an old Volvo MD6/7 typical 30+ year old POS German electrical system...Bosch and even Motorola alternators from the 70's using designs from the 60's are simply junk compared to modern systems. Moving form an external regulator to an internal one, is a BAD MOVE. The internal types are designed so they will never overcharge a battery--which means they are also designed to never fully charge it. Doubling the size of an alternator, sure, may charge things faster and even more completely--but that's comparing apples to oranges. In one case, a whopping huge fresh apple to an iddy bitty stale old orange.
Electrical systems are charging optimisation IS ALL NUMBERS. Plain objective numbers, and if you plug in the variables including budget, there's always going to be a similar answer coming out. A lot of stuff can work, or can be made to work, but if you sit down and do the math--you can always make it work better. (Unless, you're also the kind of guy who routinely breaks the bank at Monte Carlo.)