# Help tracking 72v short to chassis
**URL:** https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701
**Category:** GEM Forum
**Created:** [September 26, 2026, 4:29pm UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701 "2026-09-26T16:29:22Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@otismoon504](https://community.electricforum.com/u/otismoon504)
#### Post date: [September 26, 2026, 4:29pm UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701/1 "2026-09-26T16:29:22Z")
Hey community. While doing some testing, I found 72v (actually packV) on the chassis. Meter (black) was on B- on controller lug and (Red) was on chassis. Here’s my specs:
- All pre-2004 harnesses, components, etc
- Has the recall DC-DC upgrade
- T2 controller
- 72v Lithium
- New rebuild and still in the testing phase. No prior working knowledge of all the components"
I needed to clean up all connections more thoroughly so, I started at the B+ stand off lug with the white wire:
Disconnected DC - 72v still on chassis
Disconnected Relay - 72v still on chassis
Disconnected Buzzer - 72v still on chassis
Disconnected 20pin IP - 72v still on chassis
**When I disconnected the 23pin at controller, it went away.**
So I’m assuming the short is downstream of the B+ at Pin 1 on the controller.
Any components known to cause this issue? Any guidance or wisdom is appreciated!
Thanks in advance!
---
### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [September 26, 2026, 4:35pm UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701/2 "2026-09-26T16:35:36Z")
Connect a 10k resistor from B- to chassis. Effectively across meter leads. Chassis is isolated, floating from traction battery.
If 10k brings it down it’s fine. A high impedance meter will measure static, phantom, voltage.
If you still have battery voltage with meter shunted by 10k, then continue your search.
---
### Author:  [@otismoon504](https://community.electricforum.com/u/otismoon504)
#### Post date: [September 26, 2026, 4:52pm UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701/3 "2026-09-26T16:52:32Z")
@Inwo ok this makes sense. Im due for a new meter. I think klein makes one with built in low impedance? Prob easier to find than an actual resistor
---
### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [September 26, 2026, 10:28pm UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701/4 "2026-09-26T22:28:14Z")
That’s interesting, I did not know that, but the high impedance meters get lots of folk in trouble. They can read voltage by just touching the probes.
---
### Author:  [@otismoon504](https://community.electricforum.com/u/otismoon504)
#### Post date: [September 27, 2026, 12:35am UTC](https://community.electricforum.com/t/help-tracking-72v-short-to-chassis/30701/5 "2026-09-27T00:35:23Z")
Yup. Klein model MM720. Its pricey but worth not having those headaches. Has 6k resistor built in and design for those “phantom” readings. Thanks again!