PSDM potential failure

No, the rear brake lights work normal with the brake pedal.

1 Like

quote=AssyRequired
-Then grab the RIGHT relay. When pulled out of the holder, the beep should return (Y/N?)

No, the beep does not return.


Sorry, this was bad test. this should be done with Key OFF and brake down
Should produce solid beep.

-Pull right relay and beep should silence.

I was just trying to establish that we are working with the correct relay.


If the better test is positive we will turn our attention back to the LEFT relay.
Examine the wires going up to the bottom. Pull the cube out again and look at the top. Make sure none of the connectors have worked their way out the bottom.

You should have a Tan, Black, Org/Bk and Blu/Or wires going to this relay.
Target the Blu/Or wire and identify it’s position in the block. Run a temp/test wire from that connector down to the B- connector on the front of the PSDM.

Key ON, brake dropped.
Does the brake light go out?

Yes, solid beep

No, beep did not silence. However, when I pulled the left relay, the beep went silent. So I’m going to assume that the relays are reversed on my cart.

I ran a test wire from the Blu/Or connector of the RIGHT relay (assuming they are reversed) to the B- on the PSDM. With key “on” and e-brake down (off) the brake light did NOT go out. I double checked the test wire to make sure we had solid contact.

I then ran the test wire to the LEFT relay and got a solid beep to confirm we were testing the correct relay.

OK- Just a warning. Be careful about varying too far off script. Do exactly or do not. These two relays do/feed different things(and why I was so intent on picking the correct relay). This could have done some unpredictable damage. In this case you might have been lucky as both of these relays are switching B-.

What I did with this test is send B-(-72v) to Pin 13 on the controller. This is needed by the controller to clear the brake set check. This tells me there is a problem between this relay and the controller.

To check the wiring harness
-Key Off
-Battery Sw OFF
-pull the 23p off the controller and locate that Blu/Or wire as it comes in as Pin13. It will be in the middle of the second row.


-With the plug removed get a light on that plug and inspect it close. Look to see if the socket is damaged or different than the others.

Same goes for the controller male pins in the controller.

If you can run your meter probe to the inside of the car through the firewall, fasten it to the Blu/Or wire/pin at the relay, then touch the Pin13 in this controller plug and look for continuity between the two. To probe the controller, use a straight pin into the socket end and not your meter probe. A working theory is when you use a meter probe it stresses the spring tabs inside the socket and makes for a sketchy contact when reinstalled on the controller. (which is what appears to be happening).

1 Like

Yea, I do have a tendency to make risky assumptions. Thanks for the reminder.

Interesting, it appears that there is no wire in the 13 position. See photo. The pins on the controller look fine.

I will have to do further inspection to see where the blue/orange wire goes from the relay.

I included a picture of a loose connector coming from the PSDM. Is this for an accessory that was not installed?


Flip it around to view it as the wires are going in.
That description is misleading.
Look for the Blu/Or wire. That is the target.

As you are viewing it. Pin1 is upper right.

Yep, I understand. I will get back with you tomorrow afternoon.

Proved continuity on the Blu/Or wire from relay to Pin13 socket. The socket on Pin13 does not appear damaged or expanded.

Stand-by. Thinking about options.