solenoid resistor

[Volvo740]

Should the solenoid resistor on my TXT be hot as blue blazes even when the ignition switch is off? If not, what may be causing it to be? Thanks.

[JohnnieB]

The purpose of the pre-charge resistor between the large terminals of the solenoid is to keep the filter capacitors inside the controller charged to near the battery pack voltage so the solenoid contacts don't arc as much as they close.

It has current flowing through it all the time, so it can get mighty warm, but if it is getting too hot to touch, something could be wrong.

Might be the wrong Ohmic value or wrong power rating. For a 36V system, it is typically be a 250Ω 10 Watt resistor and a 470Ω 10 Watt resistor for a 48V system.

If it is the correct value, being excessively warm/hot can mean the controller has some internal issues and is about to fail.

What year cart and what type drive system, series or sepex?

[Volvo740]

It is a 2006 TXT Standard, 36v. EZGO just refurbished the controller, and we've replaced the solenoid. Thanks.

[scottyb]

Typically if the controller is calling for amperage to pass and the solenoid is not engaged then the resistor becomes the only path by which the control can allow amperage to flow and it will get hotter than a branding iron.

So I'm guessing your controller is ON all the time or it is messed up.

[Volvo740]

The resistor is getting much too hot. It will fry one's finger. The only way to cool it down is to disconnect a battery cable. This is all with the ignition switch in the off position. I have a golf cart guy coming to look at the cart tomorrow. If he can get to the bottom of the problem I will post it here. Thanks.

[radioman]

Another way to cool the resistor down is to disconnect one end of it.

[T1no33]

Sub'd as I am having a similar issue

[jdixon0631]

One night I was riding my cart and stopped dead in its tracks. Towed it home and after many hrs searching for the reason I noticed the resistor was glowing hot. I had a cable going to the motor had shorted on the frame. So after I fixed the cable the resistor and cart worked fine. So with that said could it be possible there is a short somewhere.

[ardb]

Volvo740 Did you find the problem with the hot resistor. I am having same situation.

[scottyb]

The resistor's function is to precharge the controller. It does this by allowing the control to draw a small amount of power through the resistor before the solenoid closes and connects full power to the control.
In normal operation the resistor may - I say may - get warm to the touch but, never hot.

The resistor gets hot when the controller is calling for power and the solenoid is not closed.