Slight shock from tire valve stem

[MrJackSprat]

I was visiting my Greyhawk this past weekend to see how she is faring this winter. She is parked outside at a friend's place though permanently plugged into 110 (shore power) keeping coach battery charged. We planned on taking it out for a drive just to keep engine healthy so i turned on my TPMS and noted a couple tires needed air.

Here is the situation, in filling the back driver outside dually (sitting on the ground) I noticed a slight shock sensation (bare hand) when I touched the valve stem... not like 110v, but maybe like 12v. At this time it was still plugged into shore power and I had the jacks down to exercise them as well. I know that the 12v system is grounded to the MH frame but not much more than that. I thought that the valve stem had a rubber seal where it contacts the wheel rim, so this is what confused me. Any ideas on what is causing this or if I should be concerned?

[wags999]

RV Electrical Safety: Part IV – Hot Skin | No~Shock~Zone

This may help you understand what potentially is happening.

Good Luck.

[chfraser01]

The only time I experienced this before was caused by a lack of ground connection at the 110 volt outlet where the RV was plugged in.

[ALJO]

Always do a polarity check before plugging in. This would be special the case if cords are repaired by new ends etc. Away from home this is even more important as many DIY think they are know what they are doing.

[retiredtech]

TPMS sensors only have a 3 volt battery in them, too low to feel. Sounds more likely you don't have a good solid ground through the power cord you're using. Might check your power with a polarity checker, which will also show grounding problems due to worn out contacts.

[Riverman]

All my valve stems are rubber through the rim, they don't conduct electricity.

[Force]

Originally Posted by chfraser01

The only time I experienced this before was caused by a lack of ground connection at the 110 volt outlet where the RV was plugged in.

x2

One time I had our last camper hooked up to an outlet that was installed in a greenhouse, which was fed via an extension cord from the main house, and that cord didn't have a ground wire. Every time DW went to open the door she would get a light zap / tingle sensation.

Ended up driving a grounding rod next to the greenhouse and wired that to the outlet to fix it

[Harvard]

open ground x3

[WeRJuliian]

Is it repeatable?
In other words, does it happen every time, or just the one time?

If it's every time, start by disconnecting the power, see if it stops. If it does, it's possibly a ground fault.

If it was just once, I'd suggest a static discharge...especially if it was cold/dry.

[curver900]

Originally Posted by MrJackSprat

I was visiting my Greyhawk this past weekend to see how she is faring this winter. She is parked outside at a friend's place though permanently plugged into 110 (shore power) keeping coach battery charged. We planned on taking it out for a drive just to keep engine healthy so i turned on my TPMS and noted a couple tires needed air.

Here is the situation, in filling the back driver outside dually (sitting on the ground) I noticed a slight shock sensation (bare hand) when I touched the valve stem... not like 110v, but maybe like 12v. At this time it was still plugged into shore power and I had the jacks down to exercise them as well. I know that the 12v system is grounded to the MH frame but not much more than that. I thought that the valve stem had a rubber seal where it contacts the wheel rim, so this is what confused me. Any ideas on what is causing this or if I should be concerned?

most likely if it was just you touching only the TPS and it is isolated it would be discharge from static electricity..

to test to see if it is something else... touch the metal frame to discharge any static electricity, then touch it again, if you get a shock there is a ground fault, if not then it is normal miserable winter static electricity... if you have cloth seats in your car you are more susceptible to static... that is why they have warnings on the gas pumps...