voltage question

[sonnysmith]

When doing the controller out put test on a ez go pds. Terminals M- and B-.
It starts out with pack voltage 38.2 before solenoid clicks. When It clicks voltage only go down to 24 or so volts, not to 0. Is this a good test for a bad controller. cart will run but very slow. I have already changed the speed sensor.

Thanks all
Sonny

[DaveTM]

Read this link: http://www.golflink.com/how_5960_spe...golf-cart.html

[JohnnieB]

Originally Posted by sonnysmith

When doing the controller out put test on a ez go pds. Terminals M- and B-.
It starts out with pack voltage 38.2 before solenoid clicks. When It clicks voltage only go down to 24 or so volts, not to 0. Is this a good test for a bad controller. cart will run but very slow. I have already changed the speed sensor.

Thanks all
Sonny

The MOSFETs are located between B- and M- (Marked A1 on some controllers) and should not be conducting until the throttle input to the controller tells them to.

What the voltage between B- and M- is before the solenoid clicks is not meaningful for the purpose of this test.

When the pedal is pushed just far enough for the solenoid to click, but no further, the voltage across the non-conducting MOSFETs should be full pack voltage. If not, there is some kind of a problem in the high-current circuit someplace.

If you do get full pack voltage, push the pedal further, which send a throttle signal to the MOSFETS telling them to conduct, and the voltage between B- and M- should decrease until it reaches very close to Zero when pedal is on floor. (MOSFETs are not perfect conductors, so the voltage will not reach Zero if there is any current flowing.)

If the voltage does not decrease at all or doesn't decrease to near Zero with pedal on floor, either the throttle is bad or the controller is bad.

You say the voltage drops to 24V when the solenoid closes and the cart moves slowly. I suspect you have a bad battery pack or bad cables/connections or bad throttle system.

Try the test again and measure the voltage when the pedal is pushed just far enough to get the solenoid to click. If the voltage between B- and M- is only 24V, find and fix the battery or cable problem.

[coppengerm]

Check the terminals on the foward reverse switch. I had a simalar problem and only reading 24 volts . Then I found the lug on FR switch that comes from the controller had melted the main board around lug. It just was sunk in maybe an 1/8" or less but after fixing it read full voltage. The cart was running much faster today than it did b4.

[sonnysmith]

JohnnieB

You are right. The controller on M- and B- had no voltage on the terminals till solenoid clicked. At that point, reading was 38.2 v. When peddle was pushed all the way down. It would only go to 24 volts, never close to 0.
Changed controller and things are working just fine.

Now for the dumb question. cart would always run, but very slow. would that be from only getting the 24 volts or some part of it ???

Thanks for the help.
Sonny

I now will close the thread.

[JohnnieB]

Originally Posted by sonnysmith

JohnnieB

You are right. The controller on M- and B- had no voltage on the terminals till solenoid clicked. At that point, reading was 38.2 v. When peddle was pushed all the way down. It would only go to 24 volts, never close to 0.
Changed controller and things are working just fine.

Now for the dumb question. cart would always run, but very slow. would that be from only getting the 24 volts or some part of it ???

Thanks for the help.
Sonny

I now will close the thread.

Only going down to 24V was why it was slow, or at least the major part of it.

The motor (armature) only had about 14.2V applied to it, so it would definitely be slow.

Glad to hear you got it going.