Yamaha 2006 G22E - input on my electrical diagnosis/solenoid not closing (helping a neighbor!)

[MomentFD]

Hi all,

I am helping a neighbor with his golf cart and am comfortable with cars and electronics and would appreciate some input on my findings from today.

It's got all new batteries at ~49 VDC, and I've marked below where this voltage is present (red).
The most immediate issue looks to be that the solenoid isn't closing. I've confirmed B+ at r/Y into the solenoid (and the fuse) but no continuity between r/B and B-. When I jump that, it closes but the cart still doesn't move. What conditions would the controller need to close this solenoid?

My other question is around the accelerator stop pedal - does 'ON" mean the pedal is depressed (go go) or up (cart is still, 0% requested)?

2006 G22E electrical diagnosis.PNG

Thanks for any input you may have, we'd love to get this thing running. I've seen the isolated motor test (battery straight to motor) and am happy to try if recommended, but the solenoid issue seems critical right now.

[golfcartg]

Production of the Yamaha G22 model concluded in 2007. All "Sepex" Yamahas, like the G19 after the mid 90s onwards share a common trait. In these models, the solenoid "B-" is controlled by the controller. This feature is implemented for enabling their promoted safety functions, preventing the cart from rolling down hills unintentionally. By regulating the solenoid "B-" through the controller, Yamaha was able to promote this enhanced safety feature.

In addressing the solenoid issue, you might want to consider bypassing the run/tow switch. This can help determine if the solenoid closure is being hindered by a faulty switch. Additionally, test the voltage to verify the bypass is successful. Although less common, a malfunctioning key switch could potentially disrupt the flow of power to critical components including the solenoid.

I was performing diagnostics on a G22 last year and customer reported the cart was operational and fully charged overnight. However, upon returning to use it, the cart exhibited complete inactivity. There was no audible beep when toggled into reverse. While measuring, it was found that there was a positive voltage of 50v at the solenoid to the battery. However, there was an absence of 50v across the solenoid terminals, needed for solenoid engagement. This discrepancy is attributed to the controller, as the negative/black wire appears to route back through the plug to the controller.

A likely scenario is the controller failing, resulting in the inability to receive negative feedback at the solenoid. Additionally, preceding this issue, the cart experienced sporadic halts, necessitating toggling into tow and back to run to activate the solenoid. This pattern of malfunction suggests a recurring problem likely originating from controller failure, upon replacing the controller the cart was back up and running.

You mentioned the accelerator pedal readings, look for a triangular shaped plug containing black, orange, and blue wires. While the specific wire designation isn't super important as long as the outcomes align correctly, test all three possible wire combinations and document the results, I forget the exact wires needed to test. Ideally, you should observe consistent readings such as 5,000 ohms irrespective of throttle position, 0 ohms increasing to 5,000 ohms as the throttle is pressed, or 5,000 ohms decreasing to 0 ohms with throttle input. Minor deviations from these values, such as around 120 ohms or less for 0 ohms or 4,675 ohms or more for 5,000 ohms, are acceptable.