1970 Safari Electrical Help Please

[oreillychris]

I have not found a thread to help with my dilemma, so here it is. My project continues...while replacing the subfloor the wire bundle, fuse panel and intelipower units got yanked around quite a bit. It's all put back together but now one circuit that includes the stove vent fan, furnace and overhead sink light are not working. I replaced the fuses, checked to see there is no voltage at these appliances, and checked with a jumper that these items still work properly.

I'm sure you can already tell I'm no electrician and at this point I am unsure how to proceed. It is hard to tell which circuit it is at the fuse panel. I have 4 20 amp fuses and one 5 amp (picture attached). When I use a meter, the first circuit to the left (disconnected, fuse removed in the picture) reads 12+ volts even with the fuse pulled. In other words that wire is carrying 12+ volts. The remaining circuits read no voltage but lights and things turn off when I pull the fuse (obviously powered). I would expect to see voltage on all circuits, but I don't, I obviously don't understand basic electric properties.....so I am guessing that the #1 circuit is the culprit because it is not behaving like the others, is this right? How do I find and maybe correct the issue?

One other item is the intelipower unit is making a whining sound and it appears as though the fan is having difficulty rotating. Can I take it apart and clean it?

Appreciate any advice, or spring to arrive so I don't need the heat anymore

[Melody Ranch]

See if you have continuity of the circuit wire....see if power is going from one end to the other. Then check the same with the neutral...ground wires. Then see if power is going thru the fuse to the bar. By the way...I hate to see a black wire attached to the ground bus bar....I always color code my new electrical systems ....white neutral, black power. Then I get a light or something (from China) with black as ground and red as power....screws up my big plan.

[oreillychris]

Originally Posted by Melody Ranch

See if you have continuity of the circuit wire....see if power is going from one end to the other. Then check the same with the neutral...ground wires. Then see if power is going thru the fuse to the bar. By the way...I hate to see a black wire attached to the ground bus bar....I always color code my new electrical systems ....white neutral, black power. Then I get a light or something (from China) with black as ground and red as power....screws up my big plan.

Thank you for the response. So, from what I have described, do you think it is the #1 circuit? That wire has 12 volts constantly while the others (that work) do not.

[TG Twinkie]

The fan in the converter is variable speed. The heavier the load the faster the fan runs.
I would look at all four DC wires that run from the fuse panel. Try to determine which color provides the power to the device that are not working. Then check for voltage. It may be as simple as the circuit is not connected.

[SuzyHomemakr]

Most of my electrical problems seem to be related to a bad ground...

[rucos]

Im with SuzyH ..... 90 % of the time its been a ground problem.......

[oreillychris]

Update, problem solved! I bet someone with some know how and a tester could have found the problem quickly, but that's not me.

After following the advice here, I was able to check the continuity of all circuits and found no issues. One note on continuity testing for the uninitiated, if there are switches in the circuit, such as a light or fan, the switch needs to be closed to get a good check...

All of the circuit wires in this old coach are red, so determining which wire goes to which appliances by color is not an option. As I described above, I suspected the #1 circuit because it had 12 volts constantly, even when disconnected from the circuit panel when the others did not. I still don't understand why, maybe an electrician can chime in.

Turns out the #1 position at the fuse panel was fried. I think at some point a line from the intellipower unit came loose and shorted on the fuse panel. Not sure of the electronics of the panel, but it was a simple matter of moving the effected circuit to an open position on the panel. Once everything was working properly, I double checked this by moving the circuit back to the #1 position and bingo! that was the issue.

I hope this might help someone else in the future. Thanks again for all the help. Press on!

[mimiandrews]

Your picture shows some damaged insulation on the wires at the left side. I'd suggest that you repair that while you're working in that area. Old fashioned black tape would do the job, but would have to be inspected often, as it tends to come loose over time. Heat-shrink tubing would work, since the damage is so close to the terminals. Or, they make liquid insulation that you can just dab on with a brush.

Also, find out what caused the abrasion that did the damage, and protect the wiring from whatever that might be.