cdi CDI box from Ebay Reverse Light Stays On

[Duane Steward]

I purchased a CDI box from Ebay that was listed as the one for a 200trx with round plug.....when I plugged it in the reverse light stays on.....what did I do wrong ? or is it just a bad CDI box?

[Frank Angerano]

Aftermarket CDI's i have never had any luck with.  NOT ONE! They do weird things to the atv. Lights, come on, blown fuses etc.

I put an oem used or new (expensive) in place and all good.  

It seems to be the most expensive parts that cost the most but work the best.   🤷🏻‍♂️

[MarkinAR]

I have read that a CDI can go bad sitting on the shelf.  Something to do with needing electricity to flow through it to keep it healthy.  There is a thread somewhere on here where a guy went through like 6 before getting one that would work. So most likely yes, defective CDI.

[Frank Angerano]

Well thats a first for me.  Maybe if it were a moist area where they were stored??
Constant electrical flow should have nothing to  with the life span of a cdi.  As long as its not soaked or hooked up backwards (battery) it should be fine. 
 

In some of my previous posts on other topics, i mention how i put a cdi in the oven for 10 min on 250 deg. Pulled it out, cooled it off and put it back on the atv and it worked for a few days until it got moist inside again. Baked it one more time and this time added silicone to the outside of the cdi and it was fine for a long time. 
 

The failure inside cdi boxes are usually caused by failed diodes.  Weather it be from reverse voltage, welding on an atv without disconnecting the wiring etc. These things wreak havoc and stops the cdi from sending voltage to the ignition coil any longer.  
 

Now if its just a moisture issue then it can be warmed, dried and resealed as mentioned above.  Just don't over cook it.   

[mikeexplorer]

Agreed, It probably got wet and that is why its not working. CDI's or any other electrical part does not need a flow of power to keep it good, pure bunk.

I don't know about other model ATV's but Arctic Cat usually encases the CDI in epoxy so its impossible to repair them, too bad, because most of the parts inside would be cheap to replace such as diodes and capacitors. Once a CDI box gets to about 20 years old, it is common for the capacitors inside to fail, then you have no spark.

Electrolytic capacitors typically only have a life of about 20 years before the plates break down inside (kinda like a battery)

Mike

 

[Ajmboy]

Updated topic title to CDI box from Ebay Reverse Light Stays On
 

[MarkinAR]

Damn. Easy there gents, I was only relaying a previous thread I read somewhere on here. But would it not stand to reason that a CDI does indeed have a shelf life due to moisture? Bare metal crusts in ambient humidity so maybe a CDI on a shelf for a few years could draw a bit of humidity? Especially given that there is no QC on imported Chinese parts? 

[Frank Angerano]

No zero! Its solid state construction.  Only way a cdi would go bad is like myself and @mikeexplorer said.  20 years plus or a cracked casing that allows moisture to get inside.   
Sorry brother i have to throw the flag here.  
 

 

[quadnut20]

On 3/4/2020 at 6:23 AM, Duane Steward said:

I purchased a CDI box from Ebay that was listed as the one for a 200trx with round plug.....when I plugged it in the reverse light stays on.....what did I do wrong ? or is it just a bad CDI box?

I only buy OEM parts when it comes to electrical

[Frank Angerano]

Agreed!