Yamaha 9.9Hp JEL Electric Start Not Charging battery.

[davidpbo]

My Yamaha 9.9Hp JEL electric start outboard does not appear to be charging the battery.

Some time ago someone posted a link to a wiring diagram for a similar engine. If anyone has a link or PDF they could post I would appreciate it. I have intermittent poor internet access whilst sailing and need to resolve this problem if possible.

I think it is a recent problem, possibly a battery charger or 10W solar panel inversely connected. (I doubt the solar panel would have done it and no fuses blew on the battery charger).

As the engine started fine I didn't think any more of it but two days after giving the battery a long charge , and running on engine for a couple of hours yesterday, very dim cabin lights alerted me to a problem.

I have started the outboard manually
but appear to be getting no output. There is only a heavy duty all +VE and -VE cable between the engine and battery. The first component in the engine the +Ve is connected to has two heavy duty connections an and one light duty one. At first thought it was a regulator but now think it is the starter solenoid. There does not appear to be any other connection to this +ve cable to the battery so I am wondering how any charge current is routed to it.

The engine is in a well and it is very difficult to see what is what on it. If anyone knows what the regulator and rectifier look like on this engine and where they are located I would be grateful also as said links to pdf copies of a workshop manual or wiring diagram.. The two fuses at the top of the engine appear to be OK. Are there any others?
T.I.A.

Not having a desperately relaxed holliday despite lovely weather, scenery etc. Depth gauge problem resolved, water bag leak/split hopefully resolved a lovely day yesterday and now this.

Battery went down to 8.5V so that is probably knacked as well.

 

[Steve65]

Rectifier may be gone

 

[VicS]

If the fuses test OK I'd suspect the rectifier.

If you have a digital multimeter with a diode test range Completely disconnect it and test each of the four diodes forward and back wards.
Each should give low reading in one direction and a very high ( opencircuit) reading in the opposite direction.

 

[davidpbo]

Found a diagram on line for an engine which shows two wires going to the heavy duty terminal on the starter solenoid. One to battery and the other to the output of the rectifier regulator. I shall have a look to see if I missed connecting that when I reinstalled the engine recently. With our modest electrical load and a fully charged battery it is just possible the battery might have held out so long, I doubt it but heh ho.

 

[VicS]

Found a diagram on line for an engine which shows two wires going to the heavy duty terminal on the starter solenoid. One to battery and the other to the output of the rectifier regulator. I shall have a look to see if I missed connecting that when I reinstalled the engine recently. With our modest electrical load and a fully charged battery it is just possible the battery might have held out so long, I doubt it but heh ho.

If you disconnected the wiring it is very likely that you did not reconnect it properly

 

[davidpbo]

If you disconnected the wiring it is very likely that you did not reconnect it properly

Unfortunately not, the second wire is manifestly there and connected, I missed it because it was too the same terminal ring within the same rubber boot. So now need to find the regulator and rectifier which I suspect may be a seemingly inaccessible black box.

 

[VicS]

Unfortunately not, the second wire is manifestly there and connected, I missed it because it was too the same terminal ring within the same rubber boot. So now need to find the regulator and rectifier which I suspect may be a seemingly inaccessible black box.

It might look something like this

 

[davidpbo]

Thanks Vic, that helped, didn't look like it had the requisite number of wires until I unbolted it. I have 14V AC across the green wires which is probably about right before it is rectified and nothing DC between red and black.

 

[VicS]

Thanks Vic, that helped, didn't look like it had the requisite number of wires until I unbolted it. I have 14V AC across the green wires which is probably about right before it is rectified and nothing DC between red and black.

Failed rectifier then.
But why?
Connecting the battery with polarity reversed will blow it instantly. I doubt if the solar panel will . Don't know about the battery charger. Disconnecting the battery while the engine is running might.

 

[davidpbo]

Failed rectifier then.
But why?
Connecting the battery with polarity reversed will blow it instantly. I doubt if the solar panel will . Don't know about the battery charger. Disconnecting the battery while the engine is running might.

And it might just have failed. There is a 10A fuse in line between regulator and battery. That had not blown either.

 

[davidpbo]

Battery appears to be no good. It has been on charge for 2 days now. Certainly yesterday it was reading 11.1 volts but dropped pdq to well below that when asked to do anything although it did start the engine a couple of times.

And all of a sudden I am getting ads for power packs!

New regulator/rectifier ordered but coming via Hermes. It will be interesting as to whether it arrives in the 2 days quoted.

Having charged the battery for 2 days it got to 11.11V and dropped to less than 9 after 1.5 hrs with no load.

 

[davidpbo]

New solid gold regulator rectifier £170+ from Yamaha. Taking the Mick I feel I bought two just to be sure.

So eBay special bought and fitted getting a V of 13.5 -14V+ from it which seems about right. With permission, I went through the marinas' batteries for recycling 3rd it 4th one showed 13.35V and started up after a couple of starts of outboard. So above charging volts was into an already charged battery. Did not read current as don't have very thick meter leads. About to fit brand new battery but might keep older one as well.

 

[davidpbo]

Getting 14.75V under way at 4.8 knots. Is that too high?

 

[VicS]

Getting 14.75V under way at 4.8 knots. Is that too high?

It is rather if you keep it up for a prolonged period.

I thought the original was a rectifier-regulator, but I am not sure what model engine you have.
Perhaps your e-bay special is just a plain rectifier. The voltage you see suggests that it is.

Once the battery is recharged and the volts start to rise switch some load on to pull the voltage down if you are motoring for any length of time.

 

[davidpbo]

I think there must be some regulation as the DC output from the bridge rectifier with a 14V AC input would be about 20V wouldn't it? I can't remember the exact ratio.

 

[VicS]

I think there must be some regulation as the DC output from the bridge rectifier with a 14V AC input would be about 20V wouldn't it? I can't remember the exact ratio.

Ratio of peak volts to rms, if that's what you are thinking of, is root2, but that is for a sine wave. ITYWF the output from the generator coil is not a sine wave. It's usual to measure the peak volts with a DVA.
I assumed the 14.75 volts was measured at the battery.

 

[davidpbo]

It was measured at the control panel in the cabin but as there was little running I doubt it made much difference. The voltage dropped considerably when I ran the electric (Peltier) fridge box so I suspect regulation not all that it might be. I shall probably be looking to replace the new regulator in the near future but actually have no idea how the original one performed.