Replacement alternator for volvo penta md 2040d

[landonshaw]

I need to replace my alternator on my volvo penta 2040d. I see a lot of replacement alternators around 125.00 verses the volvo price. If the alternator is the same amp, is it ok to buy one of these replacements?

[Tkeeth]

I have a volvo MD22. I have found I can use perkins or bosch parts as volvo just buys these and paints them generally. I don't know what model you engine is "based" on but figure that out and get a much better price list for parts. For an alternator, Might I suggest a rebuild shop? Usually you can get it cheap and keep what you have so no questions.

[a64pilot]

If your ever going to go with a high amp alt and an external regulator, now is the time.
If you want to save money and stay stock, get yours overhauled. Otherwise any alt with the correct mount and pulley will work, no engine manufacturer makes alternators

[SailFastTri]

I have a Volvo Penta MD22 and learned that the OEM maker of the alternator is Valeo Paris Rhone. You can find them on eBay new for about 1/3 the price of the ones they paint green. That green paint is very expensive.

[coastalexplorer]

Yes indeed @ $20 per aerosol can that green paint is an expensive touch of class. and not being an electrical expert this answer is based on my experience with an older Volvo Penta.

the electrical shop I dealt with expressed the opinion that there were better made alternators out there and threw mine in the garbage. I wish he has saved the pulley. there is a ratio between the diameter of the crank shaft pulley and the one on the alternator. On my 2003 that is 76 MM. but also the Vee profile has to be the same as well because the rev counter measures the electrical pulses from the alternator. Theoretically as the Vee belt wears thin the accuracy changes very slightly. However an out of dimension pulley could change this a noticeable amount.

Better minds than mine might know IF that would also affect engine hours readings used to determine oil change periods?

Another consideration is that some systems with several battery banks have an Isolator which has an amp hour rating, The system I salvaged the engine from had an Isolator rated at 70 Amp. The standard alternator was 55 amp. So IF you fit a higher amp Alternator (they changed to 105 amp/hr Delco) That battery Isolator may need changing too?. However I have been told that a 70 amp Isolator may survive IF the batteries remain reasonably charged ?

Valeo Paris Rhone alternator's supplied to Volvo Penta (in my application at least) Have a non standard pulley without a hub.

[Tom and Maje]

I have a 2040D and use the replacement alternator ordered off Amazon without a a problem it just not painted green.

[rwidman]

Many of the replacements for Volvo (or other brand) alternators are pretty miserable imitations. I found several on eBay at under a hundred dollars but the reviews were bad. It's a case of someone copying a good design with inferior materials.


That doesn't mean you have to buy a Volvo original part, but you do need to get a quality replacement and one from "Joe's Alternator Shop" is not likely to last long.

[a64pilot]

However a good auto electric shop can overhaul it to new specs for pennies on the dollar.
Properly done an overhaul is at least as good as new

[FULLCIRCLE331]

I have a MD2030 and replaced my alternator with one from DB Marine for about











I have a MD2030 and replace the shorted out original alternator witha 60 amp one from DB Marine, online, for about $130 two years ago. The comment on the pulley is true, the pull that came with the alternator gave a low rpm reading. Outside of that it works fine.

[belizesailor]

OP: why do you need to replace it?

Most common alternator problems are cheap and easy to fix.

[belizesailor]

Originally Posted by SailFastTri

I have a Volvo Penta MD22 and learned that the OEM maker of the alternator is Valeo Paris Rhone. You can find them on eBay new for about 1/3 the price of the ones they paint green. That green paint is very expensive.

+1. Volvo "original" parts are a scam...they build nothing on that engine.

[landonshaw]

I have two, had both serviced here in Grenada and one I was told would be as expensive to overhaul as to buy new. Maybe that is due to being in Grenada. Possibly taking that alternator back and repairing in the states would be the best alternative. Thoughts?

[belizesailor]

Any idea what the problem is?

Most common problems are bridge rectifier diodes or regulator. Both are cheap and easy to fix. If bearings or windings have gone you might be better to replace.

Im still running the original alternators (2) on my 2000 MD3030s...only 1 bridge rectifier repair on one alternator...other untouched. About 4,500 hours.

As suggested, if you do need to replace just get a good quality brand that is compatible. You can probably take your original into an auto parts store and accomplish that for a fraction of what Volvo wants.

Example, I bought the same make/model (Mitsubishi) of starter motor for $85 a few years ago. Volvo wanted $850! Only difference is the green paint. Zero problems.

[FULLCIRCLE331]

The original had an internal short and melted some parts. The insular on one of the terminals cracked and shorted to the housing.

[belizesailor]

Originally Posted by FULLCIRCLE331

The original had an internal short and melted some parts. The insular on one of the terminals cracked and shorted to the housing.

I meant the OPs alternator.