Controller Code 39 - Please Help

[konakid]

OK - if anyone is still listening - here is what I hope is a smoking gun.

Battery pack is 74v +. With a fresh start (after battery reconnect), key off, in Neutral - there is no error code. And voltage across Big Terminal on solenoid when hooked up is 53v+ and across Small Terminals 56v+

With key on, in Nuetral - 39 error code starts flashing. Across Small solenoid Terminals still 56v+ BUT - Across Big Terminals it read in the 20s, and I saw it slowly rising by 1/10 volt about every second (very regular). This kept going up. I checked again after a couple minutes and it was low 30s - couple mins more mid 30s - couple more high 30s.

I stopped checking and came it to write this - hoping this means something telling. I'm letting it climb to see how high it goes and what happens when it gets there.

EDIT: Ok - so after about 10 mins it rose to 55-56v - but when put in Forward and pressed pedal, still nothing.

[konakid]

Originally Posted by BobBoyce

There is no traditional F/N/R switch on AC drive carts. It's just a selector switch for 2 input wires on the controller, one to select forward and the other to select reverse. Neither selected is neutral.

You must make sure that there is + 72V applied to the + side of the solenoid coil (small terminals). Otherwise the controller will get a Main Coil OC error.

What is the proper way to confirm this?

[BobBoyce]

Put the black voltmeter lead on the negative battery pack post and the red voltmeter lead on the small solenoid terminals. One of those should be +72V when the key is on and the other shows near +72V with the key on and no go pedal applied, then goes to a much lower voltage or 0V when the go pedal is applied. It should pull in at or near 0V, then rise as the PWM in the controller starts cutting back to reduce coil current and extend solenoid life.

56 volts is too low. Your batteries may have an issue.

Bob

[konakid]

Originally Posted by BobBoyce

Put the black voltmeter lead on the negative battery pack post and the red voltmeter lead on the small solenoid terminals. One of those should be +72V when the key is on and the other shows near +72V with the key on and no go pedal applied, then goes to a much lower voltage or 0V when the go pedal is applied. It should pull in at or near 0V, then rise as the PWM in the controller starts cutting back to reduce coil current and extend solenoid life.

56 volts is too low. Your batteries may have an issue.

Bob

Bob - thanks for sticking with me on this one.

I presently have the used replacement solenoid hooked up. (The warranty/repair guy told me it was good.) However, when I put black lead on battery pack (per your instructions) I get 74.4v on one small terminal and 17v on the other. I get this reading whether key is on or off.

I might add that apparently the "old solenoid" was bad. From what I read, I should have continuity across the small terminals with nothing hooked up. I do not. Edit: after checking, I do not have continuity across the small terminals of either solenoid when no wires are attached. Should I?

Also - shouldn't I have a lower than 72v reading at the solenoid since it is rated at 48v DC

[ThreeCW]

Originally Posted by konakid

Also - shouldn't I have a lower than 72v reading at the solenoid since it is rated at 48v DC

I am thinking that you should have a solenoid that is rated for 72 volts ... is it possible that your 48 volt solenoid coil finally burnt out after having 72 volts applied to it for the past 2-1/2 years?

[ThreeCW]

Find attached a spec sheet for the White Rogers Type 586 solenoid for your reference ... I notice that no 72 volts solenoids are available in the Type 586 (assuming this is what you have).

This spec sheet indicates that a 48 volt continuous SPNO solenoid should have a coil resistance of 336 ohms.

[BobBoyce]

Originally Posted by konakid

Bob - thanks for sticking with me on this one.

I presently have the used replacement solenoid hooked up. (The warranty/repair guy told me it was good.) However, when I put black lead on battery pack (per your instructions) I get 74.4v on one small terminal and 17v on the other. I get this reading whether key is on or off.

I might add that apparently the "old solenoid" was bad. From what I read, I should have continuity across the small terminals with nothing hooked up. I do not. Edit: after checking, I do not have continuity across the small terminals of either solenoid when no wires are attached. Should I?

Also - shouldn't I have a lower than 72v reading at the solenoid since it is rated at 48v DC

No, the full 72 volts would be applied to the + side of the solenoid coil. The controller will PWM pulse the - side to above ground to reduce coil current. They really don't shoot for 48 VDC across the coil as one might expect. They apply enough current to reliably pull in the solenoid, then taper current back to maintain the solenoid in the closed state without overheating the solenoids coil. A high impedance multimeter will read a higher average voltage than what the lower impedance solenoid coil would be responding to. This is due to impedance differencess, and reactance within the coil itself as it responds to the pulsed power applied.

If the solenoid is closing when it's supposed to be energized, and opens when it's not, then actual voltage readings across the coil are not really important. If the solenoid is not responding properly, try an exact replacement solenoid. If that does not work, then an OEM programmer will be required to go in there and alter the Main Coil PWM value to reliably operate the solenoid.

Unfortunately, these days it requires more computer programming than mechanical skills to figure out issues with these modern electric vehicles.

Bob

[konakid]

Again - thanks for all the info - it is all super useful.

I started another topic (trying to limit confusion) that is just focused on this solenoid continuity issue. Pics and more info are there. http://www.buggiesgonewild.com/elect...ml#post1475311

[konakid]

This problem did get resolved. The story is on the other topic. It was the solenoid, but there is some interesting info there if anyone is interested.
http://www.buggiesgonewild.com/elect...on-please.html

[mailhot]

Good job, I have a similar issue.