PSDM potential failure

I removed the lithium battery monitor so you could see the full display. The entire background of the display is bleeding through in the photo but only the temp icon, wrench icon, turtle, one red bar, R, DL, and DH with boxes are lit up and blinking off and on.

Remember back up at around post 8 when I mentioned that it REALLY helps getting to the root of the problem if you accurately describe your situation?

With this last meaty bit of info I can go to the next level.

With the key “on” I am measuring zero volts on my multi-meter going out to the controller terminals.

Again- Clarify please(yes- it is important).
Are you measuring this on the controller itself? POS and NEG specifically???

The R, DL, and DH are all blinking with the box around them independent of the switch position.

What the (now exposed) part of the display is telling me is that the logic board of the controller is not checking in. We will get at this in a moment.

Not sure why the lithium batteries don’t register on the display.

When you installed the batteries, you bypassed the car wiring and the very sensor it uses to gather information that it needs.

Thanks for posting a pic. It even shows a missing cable off the top of your PSDM. Where did that go and why did you remove it? That was kind of important.


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Lot’s to report. Previously I had mentioned that the motor controller had been damaged at the A2 terminal due to a loose connection burn. I sent it out for a rebuild and had them reflash it to OEM specs. I received it back but did not immediately reinstall it. All previous conversations in this topic were without the controller installed. I sincerely apologize. I assumed that voltage going to the controller from the PSDM would be hot regardless of whether the controller was connected. My mistake.

After reinstalling the controller it now measures voltage across the positive and negative posts as shown on the attached pic.

As stated, the controller is now installed and the display is working properly per the attached pic.

When I installed the new batteries (in parallel), I simply reconnected the positive and negative cables from the PSDM. I did not remove or modify any wiring.

I looked at the cable connection you flagged in the pic with your arrow. It appears to point to a high voltage terminal which which comes from the negative side of the batteries. Is this correct? I have never removed any cables. I connected the thin wire to the terminal for the new lithium battery monitor that I installed when the display failed to register the new batteries.

At this point, the display, except for the battery charging, seems to be working normal. The beeper works in reverse. The hand brake sounds off when you release it prior to turning the key on. The fan in the PSDM turns on when you energize the key. BUT, the motor doesn’t engage forward or in reverse. There is no “click” when you depress the gas pedal (solenoid? potentiometer?).

motor controller
PSDM terminals

All previous conversations in this topic were without the controller installed.

Is there anything else we should know about?

I simply reconnected the positive and negative cables from the PSDM. I did not remove or modify any wiring.

Ok, so that first pic was horribly dark and that cable looked like it was missing.

But I stand by my original statement that the SOC/Battery display wiring has been bypassed by the very nature of how you are charging it.

You are plugging the Allied charger directly into the batteries → Correct?

What you are missing is that the Battery Display is a current sensing device that keeps track of the amps coming and going to/from the battery pack, applying a bit of math, making an occasional correction based on what it sees, and adjusting the bars on the screen. It removes bars as you are driving, and adds them back when charging. Since you disabled the onboard charger and are injecting power directly to the batteries the meter only sees power leaving and never going back in. It is very confused right now.


Does Allied have you charging each battery, or do you plug into one and it will charge both?

Also- When KeyON and BrakeOFF(down)
Does that Brake light go out? If so - Try PedalGo.
Does Relay Clack?

Pro Tip-
Fix this: Put a real properly sized terminal on this wire or find another place for this wire. As much as 300a can go through these big cables. Remember what happened to your connector up at your controller? yeah…

Also- those others on the other stud are wrong. Big main cable on the bottom, smaller ones up top.

Be very careful of those studs. Being only brass, they twist off easily.

No more surprises. Thanks for sticking with me.

Yes, the charger is mounted on the wall of my garage and has a coupler which connects directly to the batteries. It only has two leads which connect to the first battery of the six battery array. There is no feedback circuit similar to the original charger.

I am attaching photos of the charger. There is a charging gauge on the charger itself. The gauge is with the leads currently disconnected from the batteries.


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Did you try the car again with the brake off?
Does that light go out?

No, with the key turned on, and I release the handbrake, the brake indicator on the display does NOT go off. The brake does, however, sound off when I release the brake with the key turned off.

Understood and will do. However, the smaller cables on the stud to the right were installed by the factory. I have not altered any other wiring.

How is the level in your brake reservoir? If low it will also set off that light.
If unsure, unplug the sensor that is placed in the reservoir of the brake master. (note: I am not referring to the pressure switch down lower).

Guess we should confirm the seemingly obvious… Is the motor installed? :rofl:


Just got home and checked the brake fluid. It might be a little low, but I went ahead and disconnected the sensor wiring. The brake light did not disappear.

Touché - the motor is installed.

Good morning AR,

Thanks for you help so far. I am still trying to energize the motor so I can test the rebuilt controller for proper speed. As I stated above ^^^, I checked the brake fluid and sensor and everything checks out OK. The brake light on the display stays on with the key “on” and the e-brake handle down(off). I reviewed another thread of yours regarding 2 cube relays on the right side under the windshield. Both relays “click” (pull in) when reinserted and when reversed (left to right). The brake light stays on. I would appreciate you further analysis.

On My car the left cube relay controls the light and the right sets off the constant beep.

Verify for me that these relays are at least clicking.

-Main Power ON
-Key Off
-Brake down
→ produces solid beep. (Y/N?)

-Then KeyON
→ beep silenced
→ Brake light should go out - but in your case light still on? (Y/N?)

-Then grab that LEFT relay and pull it out of it’s socket. Do you feel it click when you pull it out and re-insert? (Still no change to the brake light Y/N?)

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

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do the rear brake lights stay on too?

Yes, the relays are both clicking.




No, the beep does not return.