Resister, diode, and yellow flat cap Identification Help Plz.?

[Randy018]

HI guys, acquired this cart a couple days ago. I'm 0-3 so far on making a cart work. I hoped this being a 1992 it would be the similar as my 1990, I can not seem to fix, or close. I now see it has an electronic controller. My lack of cart knowledge has again bitten me. Just to begin I see burnt wires on the above mentioned parts. I of course fear the controller is also shot. Can any one ID that diode size and that flat yellow cap, No numbers on it at all. Thanks in advance.

[scottyb]

the yellow item is a varistor. I have seen more of these burnt than intact on running carts. The general consensus is that it is not needed.

Does the solenoid click when you try to go?

[Randy018]

Yes Scotty the solenoid clicks. The diode checks good and the resister as well. I cleaned and resoldered the resister. I think I will try and check the controller. The only repair manual i have is for a curtis 1206, witch is different. I've spent the last hour looking thru post for this exact troubleshooting manual. YOU guys keep us sane trying to learn about these carts. Thank you in advance.

[FF Titus]

The resistor on the solenoid in the 3rd photo on the left terminal looks snapped off.

[scottyb]

Originally Posted by FF Titus

The resistor on the solenoid in the 3rd photo on the left terminal looks snapped off.

Yeah, It's been repaired. See post 3

[radioman]

That yellow component is a metal oxide varistor (MOV) as scottyb mentioned. It is used to suppress voltage spikes. It begins to conduct when the voltage spike reaches the voltage the MOV is rated at. They often short out when they get more power spike or over voltage and in this case it looks like the lead is burnt off rather than cut. It has a purpose probably to prevent spike voltages from damaging the controller. However the cart will run without it but it might be a sign something else is bad.

[Volt_Ampere]

Movs usually sacrifice themselves when spikes happen. IMO they don't offer much protection.

[Randy018]

Thanks for the comments. I pulled the solenoid and the controller out for inspection. Solenoid checks good plus it clicks pretty hard. I dont have the correct trouble shooting pdf for this cart. I am guessing the controller which is a Curtis 1204-027 might be the culprit. I'm gonna continue to read the post and check as I go before i replace the controller. Thanks again for the comments !

[radioman]

Originally Posted by Volt_Ampere

Movs usually sacrifice themselves when spikes happen. IMO they don't offer much protection.

I would replace it. It may help clamp voltage spikes from the motor and save a controller. It is a sign something happened between B+ and B- that is not normal. If it shorts out from excess voltage or a spike the wire lead acts as a fuse and burns into. It has done its job.

[whizzo]

I cant give you any information on the MOV appart from saying it needs to have a break over value higher than the supply voltage and to say.....considering the heavy current and the large back EMF spikes from the motor..a pissy littl MOV like that wont help much and is likely to live a very short life....if you want to fit a MOV or a transorb there..think chunky.

as for the diode across the main solenoid..it is a common or garden silicon diode..anything in the 3 amp or greater range will do the job like a 1N5404 or 1N5408...there are better ways of mounting the diode too.

The resistor value is not particularly critical and the value on the diagrame for a cart running a similar voltage should be fine.....it just keeps the controler alive while the main solenoid is open....

A larger wattage resistor and a better mounting option will not go astray.

hope this helps.

cheers