[ET 300]

Thought I’d post this FWIW. I’ve been babying a weak battery getting the last ounce of life out of it. Plus didn’t want to spend money on a new battery. LOL. Well about a week ago I started her up on a cold day. I didn’t give her time to warm up before attempting to drive off. The engine stalled. I figured I had one more try to start with battery before kick starting it. Hit the starter button, loud explosion in the front end. Then I noticed neutral light off; I had a complete power failure.

So I removed the fender for access and found the ignition module or CDI Had burnt up. It had that familiar burnt electrical smell plus it was leaking a dark brown liquid with that same smell.

Called around for parts and OEM was $250.00. Found an aftermarket part with good reviews so I decided to take a chance; $31.83 including shipping. Part was ordered but got delayed due to the cold wave weather.

In the meantime I did some inspections and electrical checks to see if anything else may have been harmed. Couldn’t find anything. So I checked the starter circuit from battery to fuse to neutral ground. All checked good. Wait on part.

Well I got the part, installed it, flipped the switch and got nothing. No green light, no start, nothing. Back to the schematic looking for a problem. The problem was I couldn’t find a problem. That start circuit should have worked. Checked for ground again. Checked that tranny was in neutral. All good and nothing, no light.

I looked at the diode which puzzled me. The manual says check with an ohmmeter. I tried several meters and diode failed the test in each case. So I tried a homemade tester that I make. It checks for voltage and continuity and uses a horn powered by a 9 volt battery. Well, when I checked it with my tester, the diode tested good. I found the number 3.7 stamped on the diode. I figure this is the forward voltage needed for it to work. Correct me if I’m wrong. I didn’t replace the diode.

I decided to go back to basics, start at the beginning. Decided to check power at the ignition switch. Well no power there. So it had to be the fuse, which I had checked. Opened up the fuse holder and the glass tube fuse was in parts. Pulled the spare fuse and it too just broke apart in my hand. Checked the second fuse but it was good so left it in place. These are original fuse so about 25 years old. Put in a new fuse and the wonderful sound of a running engine filled my ears. Happy to be in the Saddle Again. Sorry for the long post. Oh!! time for a new battery.

 

[Goober]

Good job!
It’s tough to know when a battery is done unless you know how to do a load test.
Glad you were able get in there and find the failures

 

[LedFTed]

fuses

what year atv ya got so i might learn something. also, can ya still find those fuses?
it's not like i am an old one, at 63, but ya can never tell, when ya need a glass fuse. :smile

 

[ET 300]

Thanks. Yes a battery load test is a must when you suspect a battery issue. Mine tested into the weak range. But if I ran it everyday, it would start the next day or easily kick start. That’s how I kept it going. It is a work horse so I use it practically everyday.

Regarding the CDI failure, good that it went out with a bang. Made finding the failed part easy. Not sure what caused it to explode. See picture, lower left all burnt up. Still smelly.

My model is a 1994 4 wheel drive. All original, dependable. Just routine normal maintenance. This was the first issue of any significance.

The fuses are available but not as popular as before. I got mine at NAPA. The newer models have gone to the blade type fuse. If I have another fuse issue I will change over to blade type. Easier to service. My fuses were in a protective rubber cover that you separate for access to the fuse. Then the fuse is in a plastic case which was hard to open and hardly any room to work. Blade fuse is much better.

 

[ET 300]

Thought I’d post this picture in case it may help someone. Lots of testing gets done here. For the connector box you remove only the bottom bolt. The box cover then opens up. Here you will find wire connectors for different systems. Here is where I tested for ignition switch power. Buried behind the wiring you will find the diode.

One point about starters. If you think you have a bad starter don’t go out and buy a new one. Your old one may be good. I’ve found that the brushes in these starter are very dirty. Thus they get the starter dirty and over time the starter fails. Opening the starter up and doing a brush replacement or just a cleaning, commutator bars, may get you going. Not hard to do.

My starter is original from 1994. I’ve replaced brushes about 3 times and have just cleaned it a few times. Still going good.

Anyway, just my 2 cents.