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-   -   Volvo MD7A Alternator (http://www.sailnet.com/forums/gear-maintenance/12392-volvo-md7a-alternator.html)

jthomas5 01-28-2006 01:42 PM

Volvo MD7A Alternator
 
The original alternator on my 1981 Volvo MD7A has gone bad. I took it to an alternator shop, and they said it could not be rebuilt - can''t find parts. The cost of a replacement from Volvo is $677. Does anyone know where I can find a less expensive replacement for this engine?

sailingfool 01-28-2006 05:23 PM

Volvo MD7A Alternator
 
jthomas

Good luck, you are looking for parts for a boat, "less expensive" is for what''s parked in the parking lot, not for what is tied up at the dock. If you think this part is expensive, wait until you need something more esoteric and then you''ll see sticker-shock.

Remember what Vanderbuilt said about boats "if you ahve to ask what it costs..."

SeanC. 01-28-2006 06:51 PM

Volvo MD7A Alternator
 
no need to bum him out so quickly...if you look theres usually cheaper ways around things.

I don''t know much about the subject, but I''ve always seen adds for Balmar alternators. Aftermarket is almost always cheaper than oem gear. www.balmar.net
-Sean C.


jthomas5 01-29-2006 02:10 PM

Volvo MD7A Alternator
 
Sean, thanks for the advice. I''ll give them a try.
Jim

kentg 02-02-2006 04:16 AM

Volvo MD7A Alternator
 
I just had my stock alternator from a 1982 MD7A rebuilt after being told it was not possible. I live in Tacoma, Washington and there is a good rebuild shop here called Sound Starter. Cost me $125.00 to do the alternator and $150.00 to do the starter. May be worth shipping costs. Depending on the type of use, the stock one charges just fine.

dman 02-10-2006 03:13 AM

Volvo MD7A Alternator
 
When you say the alternator needs to be rebuilt,did you find the problem?Is it bearings ,windings,brushes........etc.Rebuilt to some is just 2 dollar brushes.I`m curious to know what parts are required that cannot be found.


jthomas5 02-11-2006 04:05 PM

I was told that the stator core was burnt and a replacement could not be located. I have since found a replacement alternator at Arco Marine for under $350. Their part #82100.
Thanks, everyone, for your interest and advice.

dem45133 12-13-2008 02:48 PM

MD7A Alternator
 
I know this thread is old, but Thought I'd revive it with my own MD7A alternator need. Does anyone know if the original DEV Marchel A14/35 alternator is actually intrinsic? I am in the process of rebuild the starter... nothing is really intrinsic about it since the drive end is wide open to the atmosphere. Intrisic to me mean fire/ignition proof... meaning 100%. Its a deisel so maybe its not as important when compare to gas.

I am looking for for a generic LOW cost... yea <$50 or 75 automotive alternator that can be wired in. Mount up can be built to suit (professionally.. I have the equipment). There is nothing really magic about an alternator to ever make a 35 amp alt worth $350 or 400 and whatever. Oh and don't tell me about marine environments... ever run in the salt laden roads and rain in you car or truck... they hold up just fine even if the outside gets a bit corroded. Actually the inside of my boat is much dryer than anything under the hood.

Sorry, I guess I'm just too practical and know a little bit too much about mechanical systems. I am really getting tired of the Marine industry thinking that Everyone who happens to own a boat is independently wealthy. My ready to sail 30 year old 27 footer cost $800. If it had cost 8k or 80k I couldn't own it.

Any ideas? Thanks.

mitiempo 12-13-2008 03:20 PM

Volvo is notorious for their extreme parts prices. I agree that a marine installation can be dryer and cleaner than automotive use. Could it be that Volvo uses a generic alternator before their logo goes on? What is the difference between a marine alternator and an automotive one? I think not too much, but would like the experts to chime in with their .02 worth.

Rockter 12-13-2008 09:22 PM

Jt :

I have the Volvo MD17C, from 1977.

I can recommend highly the 100 A "small frame" alternator from the American-supplied Ample Power together with their (separate) 3-step regulator. I bought that set-up in 1992, and it's still going strong. It is, apparently, capable of 100 A continuous output when the temperature is 93 degC. I trust that is the air temperature. That is very hot indeed. Even in the tropics, your engine room, properly ventilated, will not reach that. Here in Scotland, I always leave the engine room wooden panels off the motor, such that the engine an alternator breathe cold.

Jt, everything hinges on the "continuous output" rating. I bought a rival's 100 A alternator. It lasted one half of an afternoon. I kid you not.

The Ample is not cheap, but it just keeps rolling....

Ample Power Alternators

.... I think mine is the 4023.

Of all things, at heavy alternator loadings, spin the engine fast. Keep those revs up. The big centrifugal fan on the front of the alternator must be kept spinning fast. The alternator cooling thrives on revs. Cooling is everything to the alternator. When you first begin a re-charge, rev the motor and hold the revs up until the charge current drops off. When it drops off, you can drop your revs a bit, and given time, you can drop to idle again if you wish.

I have no other interest in Ample Power.


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