DVM Failures

[MauiHoss]

I put one of Scotty's DVMs in an EZGO PDS cart a while back at it failed. First it had wildly erratic readings from low 20's to actual voltage at any given time. I asked Scotty about it at the time and he suggested checking the wiring which I did. Not only did I have continuity but my my hand-held DVM read pack voltage at the meter connections. Eventually it failed completely so I got a new one.

The new one worked great for one day before failing completely just like the other. I thought it might be a voltage spike or due to lots of rain (cart lives outside). Scotty tells me they can handle up to 100V and they are totally waterproof.

I tested the failed DVMs on another cart and they are truly dead. Both carts have the same type of wire from the battery pack to the meter.

So I put it to the experts here... what could be killing my DVMs?

[cgtech]

Perhaps the cart solenoid does not have a clamping diode on it, and constant voltage spikes are hurting them.

[NCPW]

Could be just bad DVMs. I too have got one from Scotty and it failed after 18 months. Same as yours, erratic readings then one day I go to ride the cart and notice the DVM reads 20something... I freak for second thinking I left something on and killed my batteries. Check it with my hand-held and the pack reads above 53V.

I ordered a new digital VM, same as the one Scotty provides and its still working almost a year now.

Maybe you got a couple of lemons.

[scottyb]

I do get one failure in 500. There just are not that many lemons that one person can get 2 bad ones?
GCtech may be onto something.