I have a resistor on the controller ??? 92' marathon

[EZHO]

92 Marathon elect'
Standard Solenoid and F-R Switch
Controller - Curtis pmc 1204-027 / 275a / 24-36v
Motor - G.E. mod 5BC48JB1061 / HP4 / Amp 102

Haven't seen this on any other carts yet ?
or on any of the parts sites listed for controllers , only for solinoids
is this even supposed to be there .
if yes , is it facing the right way
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just Bought the cart last week !

[JohnnieB]

That is a new one on me too.

It appears to be a resistor and it appears to be connected between the controller's B+ and B- terminals.

Being a resistor, it does matter which end is connected to B+, but I have no idea why a resistor it is connected between those two terminals.

It is difficult to read the color code in the picture, but it looks like a five or six band resistor with the first three bands being Brn - Blk - Brn or 101 (before I get yelled at - five and six band resistors have three significant digits instead of two) and the fourth bad is Brn (x10), so it appears to be a 1,010Ω resistor.


You should have a 250Ω resistor between the solenoid's two large studs and a diode between the solenoid's two small studs with the banded end attached to the small stud with the positive voltage on it.

[EZHO]

............and a diode between the controller's two small studs ?
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I have a diode between the two small studs on the Sol'

all 4 studs on controller are 5/16 lug type? (no small studs)

so , should i take it off then ?

[JohnnieB]

Originally Posted by EZHO

............and a diode between the controller's two small studs ?
.
I have a diode between the two small studs on the Sol'

all 4 studs on controller are 5/16 lug type? (no small studs)

so , should i take it off then ?

Should have said solenoid's two small studs. I corrected it.

Yes, I'd take the resistor off the controller B- and B+ studs. I cannot figure out a reason for it to exist.

[EZHO]

Thanks jonnyb ..........

was asking because I tried the solenoid test for the first time this morning , and if i remember right i was getting 36v to other/side of Sol without pressing the pedal ( with resistor off ! ) and was wondering if that controller resistor was throwing power to it ? . not going to go back and recheck now . its running great ....

[EZHO]

Just came across another guy on the site thats using one alot bigger than mine
pic' of his is below ?

I took mine off and everything seems OK so far
anyone else have one of these on theirs . .

[LukeL]

Exact same thing on my marathon.


Sent from my iPhone using Tapatalk

[cgtech]

Lukel, the yellow one on yours is not a resistor, but a MOV (and yours was factory installed). Different animal. seems to me like the resistor in the prior examples would be fighting the precharge resistor on the solenoid, and wasting power. I have never seen the prior resistors installed like that from the factory.

[JohnnieB]

The resistor between B- and B+ parallels the filter capacitors inside the controller, so it draws additional current through the pre-charge resistor on the solenoid while the battery pack is connected and dumps the charge on the filter capacitors faster than normal when the battery pack is disconnected.

Assisting the internal filter capacitor discharge circuit is the only purpose I can come up for that resistor and I wasn't aware the internal filter capacitor discharge circuit needed any help.

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The attached schematics for a Marathon controller cart shows the MOV in two different locations. B- to B+ and A2 to B+.

[EZHO]

I had to research what a MOV was / " Radioman" posts were the best source i found
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Radioman / not in any particular order.

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.

The only information I could find on MOV's for golf cart applications is they are rated at 75 volts. If one fails it is trying to tell you your controller may be next. A little spike is all it takes to ruin a controller. It would be hard to prove if a MOV helps protect a controller against spikes or not but I bet it was put on there for that reason.
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Perhaps it was included by EZGO to take care of small harmful spikes in new carts hoping it would reduce warranty expense replacing controllers. If a bigger MOV was used with bigger leads it may create a fire. If you had a cart with one that had a burned lead and it was rated at 75 volts and you tested the lead stub and it was shorted what would you suspect?
.. From what I can tell it is connected across B+ and B- on the controller terminals. I cannot think of a reason to have a MOV across the battery terminals at the controller other than to help protect the controller from voltage spikes.
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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.
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So............most people here seem to think it only offers minimum protection at best
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I'm thinking i should use , it is on the diagrams ,but which of jonnyb's diagrams should i use , B+ to B- ( or ) B+ to A2


Thanks to LukeL , cgteck , and jonnyb , i cant believe how much I've learned in 1 week thanks to you guys