Evinrude Rectifier Problems

[John Varr]

I've got a 97 Evinrude 90 that has blown several rectifiers. I have a dual battery setup with a Battery 1, 2, or Both switch. All battery connections are clean and tight, but if I cruise at high speed with Both batteries charging, that seems to be when the rectifier will blow. Neither of the batteries is really run down when this happens. Since this is an unregulated, 6 amp rectifier circuit, is it possible that charging two batteries at once is drawing too much current for the system and blowing the rectifiers? Not sure what else could be happening. I don't know if it's coincidence, but I've never had this happen when only battery is on the charging system.

 

[angus63]

Re: Evinrude Rectifier Problems

Welcome Dog<br />Are the batteries the same size and type? I'm pretty certain it is a no-no to run on both if they are not identical. I always run on one or the other, and only use both to start the motor in the colder months (northeast in November). I have never had a regulator issue running on one battery. I am pretty sure it's a good thing to have a large load on an unregulated system so as not to boil a battery. So in conclusion, I'm really not helping much and just adding to the confusion. I'll shut up now....<br />Good luck

 

[John Varr]

Re: Evinrude Rectifier Problems

That's a great point, Angus. The main reason I have both batteries on together is because it keeps one from overcharging. I've actually considered looking for an after-market regulator setup so I don't have to worry about cooking the batteries. To answer your first question: Both batteries are not exactly the same. They are both starting batteries but different makes and ages. I thought worst case was that they wouldn't charge fully in that scenario but never thought about drawing too much current. Hopefully someone out there has a pearl of wisdom on the subject.<br /><br />Dog

 

[Seasport]

Re: Evinrude Rectifier Problems

Sounds like you are drawing too much current in charging the two batteries and frying the rectifier. Although I'm surprised the alternator can provide more current than the rectifier can handle. You can get a regulator & rectifier for that motor but this may mean a new stator as well. Expensive. Maybe best to charge just one battery at a time.

 

[Silvertip]

Re: Evinrude Rectifier Problems

First, you can't get blood out of a turnip so you can't draw more than 6 amps from a 6 amp system (which you don't have). If you indeed have been installing a 6A unregulated rectifier its no wonder its blowing. All electric start models 40HP and larger have regulated systems. A 95 40HP has a 12amp system for example. I don't have the specs in front of me but I believe your 90 HP has a 20 amp regulator. Get the correct regulator and you will have no trouble charging both batteries at the same time.

 

[BoatBuoy]

Re: Evinrude Rectifier Problems

According to the parts list at ishopmarine, yours takes a 20A rectifier/regulator.

 

[John Varr]

Re: Evinrude Rectifier Problems

Believe or not, this is the correct rectifier for the model motor I have, and it is unregulated. I've confirmed that in my shop manual and with the Evinrude parts retailer. There was also a rectifier/regulator combo available for this motor, but that's not what this one was set up with. And I have to disagree that you can't draw more than 6 amps from a 6 amp system. A dead short across any power supply will draw more than the sytem is designed for and something will blow. That's the whole purpose of a fuse. In this case, the rectifier is the weakest link. So I have to believe that it's just a marginal design and charging two batteries is asking for trouble. <br />Thanks for the input!

 

[OBJ]

Re: Evinrude Rectifier Problems

ScuabaDog....just fer kicks...post me your model number please.....thanks.

 

[John Varr]

Re: Evinrude Rectifier Problems

The plate on the motor says XE90TSLEUA<br /><br />Dog

 

[OBJ]

Re: Evinrude Rectifier Problems

The correct part number for your Rec/Reg is 585195. Is the part number you got?

 

[John Varr]

Re: Evinrude Rectifier Problems

No, that's the regulated version. I have the unregulated rectifier 583408. More than one Evinrude dealer has told me that both were used on that motor. I don't know if they're interchangeable, however.

 

[BoatBuoy]

Re: Evinrude Rectifier Problems

OBJ,<br /> You're quite right. However, the L in the model number denotes 20". It looks like the rectifier for the 20" is one of the small ones, part # 583408. Quite a difference in same year/hp motors.

 

[Seasport]

Re: Evinrude Rectifier Problems

I guess the question to answer is will the alternator consistently provide more than 6 Amps and enough current to burn out the rectifier. Maybe, although the stator is rated at 6Amp. For this model, there are two different stators - one 6A version (20") which mates with the rectifier and one rated at 3/9A (25") which is meant to mate with the regulator/rectifier. Have you checked that you are mating the rectifier with the right stator?

 

[John Varr]

Re: Evinrude Rectifier Problems

I don't know if there's an easy way to check the stator. I've assumed they were mated correctly because the 6A version was a valid option for the model. So the answer to your question is no, I haven't checked. 6 amps doesn't sound like a whole lot of current to charge two batteries, however, which made me wonder about the dual battery question in the first place. I'll see if I can determine the stator type but I'd be really surprised if it wasn't the 6A version. <br />Thanks.

 

[Seasport]

Re: Evinrude Rectifier Problems

I guess if the rectifier was on the motor to start with, you'd expect it to be mated to the correct stator (unless someone else has previously put the wrong part on). You would think though that the rectifier would be able to handle all the current that the stator windings could produce. Maybe the recitifer/regulator assembly is compatible with both stators - in which case you could fit this instead and get a regulated output (although this doesn't necessarily mean you will get less charging current into two batteries).

 

[John Varr]

Re: Evinrude Rectifier Problems

I think that the bottom line is that the rectifier is part of the circuit that the stator and the rest of the boat's electrical system are on. So if anything on the boat draws more current than the stator is capable of handling, you would want the rectifier to burn up rather than the stator; It's a much cheaper part. Makes me wonder why they didn't just put a fuse on the rectifer though.

 

[OBJ]

Re: Evinrude Rectifier Problems

I stand corrected BoatBuoy..didn't look far enough. This is what I think....it is very possible for one battery to be charged to a higher lever than the other. So the higher charged battery can discharge back through the rectifier positive side to the lower charged battery. The rectifier burns out. Got no place to go. That's what battery isolators are made for. To protect the system.

 

[angus63]

Re: Evinrude Rectifier Problems

That's what I was thinkin' but OBJ said it much better!

 

[Seasport]

Re: Evinrude Rectifier Problems

But hang on, the two batteries are either isolated from each other or directly connected together by a switch. Any current flow between them will be directly via this switch. A battery isolator prevents a discharged battery from draining a good battery. Can't see how you would get current flow via a reverse biased diode?

 

[R.Johnson]

Re: Evinrude Rectifier Problems

Take a look at that switch, is it a make, before break switch? Are you ever turning the switch with the engine running? My guess is the switch, and you are switching with the engine running, you are taking the battaries right out of the system when you do that. Think of a bad connection. You can't cook a battery with a 6 amp charging system with the time you run an outboard motor.