Failing in the simplest way

[Squigie]

I spent 6 hours troubleshooting, testing, removing, disassembling, testing, partially reassembling, retesting, reassembling, reinstalling, and retesting an RV furnace today.
My multimeter decided not to work*, so it was all done with trial and error, based on diagrams and schematics for the furnace.

Everything worked on the bench.

But it still didn't work in the RV.

Finally, we traced the wires, through the floor and bulkheads, back to the inverter, to the fuse block, to the battery.

Polarity was reversed.

That RV is a white-ground, black-positive setup. But the factory wire harness changes to RED wire for the negative battery connection, for the last 4 feet of the run. So there are black and red wires running to the battery.
But they don't go where you think they go...




*(I may have accidentally popped the multimeter by having it in "continuity" mode and sticking the probes into a hot 440 VAC outlet. Maybe. No one saw it. You can't prove anything.)

[lfhoward]

Wow, nice work tracking that down. That took some persistence and patience I bet.

[Modstock]

Plot twist;;;;;;;;;;; the RV was testing you.

Sent from my H1611 using Tapatalk

[twisted lines]

I went fishing with a Cougar Catcher Friend of mine that retired as a electrician always a blast, one time had all my stuff hooked up to his downrigger and he didn't put them in the correct spot, 4 of them. They were not hooked up the same (Correctly) mine was power down or free wheel down no stop or up so he cut the cable and on we went with three downrigger's.
Whow that was a moment
Mick may remember the power on the cable story we didn't catch fish that day.

[pchast]

*(I may have accidentally popped the multimeter by having it in "continuity" mode and sticking the probes into a hot 440 VAC outlet. Maybe. No one saw it. You can't prove anything.)

Pull the meter apart.......... There are often internal fuses to save the meter from this!

[MickinOz]

I went fishing with a Cougar Catcher Friend of mine that retired as a electrician always a blast, one time had all my stuff hooked up to his downrigger and he didn't put them in the correct spot, 4 of them. They were not hooked up the same (Correctly) mine was power down or free wheel down no stop or up so he cut the cable and on we went with three downrigger's.
Whow that was a moment
Mick may remember the power on the cable story we didn't catch fish that day.

I wouldn't use the whole let's attract fish with 'lecktrickery thing anyway.
I believe there are certain really big fish are very sensitive to electricty.
The last really big fish I attracted to the boat was about 18 feet long, dark grey on top, white underneath, had a pointy nose, big brown eyes and really big teeth.
Down here we actually leave the motor in gear while off, so even the propeller doesn't spin in the tidal stream.
Once the boat is located on the drop, even the echo sounder gets turned off.

*(I may have accidentally popped the multimeter by having it in "continuity" mode and sticking the probes into a hot 440 VAC outlet. Maybe. No one saw it. You can't prove anything.)

No one else has ever done that. Ever. Honest.

[Squigie]

Pull the meter apart.......... There are often internal fuses to save the meter from this!

Fuses were checked, and one replaced, after the 'incident'. Still no worky.
No obvious exits for the magic smoke. No charred remains of angry pixies.
Some functions appear to work, but don't seem accurate.



It's about 25 years old, and twice the size and weight of a comparable, more modern multimeter. I wanted a new one anyway.
I'll probably pick up another analog meter, too. I gave mine to one of my brothers about a decade ago and never replaced it.

[saltydawg]

I use a cheap klien multimeter most of the time, but I do have a simpson 260 I like to break out just to mess with the youngens.

BTW I am a master electrician with 27 years in the trade, now do design and estimating with a little bit of PM sprinkled in.... I like my indoor plumbing and ac at the office.

[Tom&Shelly]

Pull the meter apart.......... There are often internal fuses to save the meter from this!

Fuses were checked, and one replaced, after the 'incident'. Still no worky.
No obvious exits for the magic smoke. No charred remains of angry pixies.
Some functions appear to work, but don't seem accurate.



It's about 25 years old, and twice the size and weight of a comparable, more modern multimeter. I wanted a new one anyway.
I'll probably pick up another analog meter, too. I gave mine to one of my brothers about a decade ago and never replaced it.

I have an analog Lafayette (anyone remember that brand?) multi-meter my folks gave me for my tenth birthday, which makes it about 48 years old. (And yes, I worked on projects at that age where it was helpful--didn't need to borrow Dad's Simpson.) I seem to remember zapping it once with high voltage while it was in one of the resistance settings. I think the rotary switch terminals fused together because I scraped clean the spaces between them on the circuit card and it worked again.

Today, my go to is the $7 (free with a coupon) Harbor Fright digital meter, but once in awhile an analog meter is nice to use.

Anyway, analog or digital, you might try it...

Tom

[Philip]

I may have accidentally popped the multimeter by having it in "continuity" mode and sticking the probes into a hot 440 VAC outlet. Maybe. No one saw it. You can't prove anything.)

Your lucky it didn't explode in your hand. Seen that happen a few times over the years. By me and a few other maint techs.

All you can do is say oh darn. I really liked that meter.