AC power indicator light won't work.

[blickcd]

I have a 1979 International 31' center bath, and the AC Power (shore power indicator) light does not work. This light is an LED at the left end of the battery and tank level monitor panel, which is located over the stove.

Having done some research, I know that the original Univolt battery charger (long gone) when plugged in would ground a gray wire and activate that LED. This gray wire is located in the 12 volt fuse panel below the front window, first fuse holder on the left.

In theory, connecting a jumper wire between this gray wire in the panel and the bare copper chassis ground wire for the battery charger will turn on the AC Power indicator. Supposedly others have done this and installed a 120 volt relay to switch on the light when shore power is plugged in and I would like to do the same, however I can not get that indicator to light up.

Here is what I have checked so far: The gray wire between the fuse panel and monitor panel has continuity. There is continuity between the chassis ground wire and random spots on the trailer frame, as well as the negative buss in the fuse panel. No burned out electrical components have been found on the monitor panel circuit board, including the LED I am trying to activate. Note that I have only checked the circuit board at the left end to roughly where the circuit for the battery meter appears to begin.

I know I am being obsessive with this, but I would like to get that light to come on as originally intended. Any suggestions are welcome.

[Alumaholic]

Did they have LEDs in 1979?

[AYRSTRM2]

Originally Posted by klevan

Did they have LEDs in 1979?

b

Uh, yeah. I had one of those unexplicable LED digitial watches in second grade in 1975. Here's the Wikipedia entry on LEDs.

[AYRSTRM2]

Originally Posted by blickcd

I have a 1979 International 31' center bath, and the AC Power (shore power indicator) light does not work. This light is an LED at the left end of the battery and tank level monitor panel, which is located over the stove.

Having done some research, I know that the original Univolt battery charger (long gone) when plugged in would ground a gray wire and activate that LED. This gray wire is located in the 12 volt fuse panel below the front window, first fuse holder on the left.

In theory, connecting a jumper wire between this gray wire in the panel and the bare copper chassis ground wire for the battery charger will turn on the AC Power indicator. Supposedly others have done this and installed a 120 volt relay to switch on the light when shore power is plugged in and I would like to do the same, however I can not get that indicator to light up.

Here is what I have checked so far: The gray wire between the fuse panel and monitor panel has continuity. There is continuity between the chassis ground wire and random spots on the trailer frame, as well as the negative buss in the fuse panel. No burned out electrical components have been found on the monitor panel circuit board, including the LED I am trying to activate. Note that I have only checked the circuit board at the left end to roughly where the circuit for the battery meter appears to begin.

I know I am being obsessive with this, but I would like to get that light to come on as originally intended. Any suggestions are welcome.

This was being discussed in the thread I started on Univolt Wiring Replacement, specifically this post, which just refers you to another thread and post, but you'll get there eventually.

[blickcd]

In short it looks like there is no easy way to make that light work again.

I've read most of the messages in those links as part of my earlier research. It looks like early 70's models used an incandescent bulb which could be activated by grounding the grey wire. However, the late 70's models with LEDs are more complicated. I did notice power coming in to that light from two sides when checking with a meter, and a pair of diodes evidently keeps it all under control.

The only way I see to make it work again would be to somehow build a portion of the old Univolt circuitry from scratch and connect that to the grey wire. If anyone can provide a schematic that would be great, otherwise I will give up on this for a year or so.

Thanks,
Christopher

[Chaplain Kent]

I use a meter which I peurchased at Camping World. The light did not tell me when power was not adequate, the meter does. All you need to do is plug it in.

[davidz71]

Just go buy one of those circuit receptacle testers which lights up with 2 yellow lights on the righthand side if the circuit is alive and correct. Plug it into a receptacle easily visible and when shore power is on, so is the circuit tester. It is a cheap and easy way of taking care of the problem.

[azflycaster]

The PO left both for me....
BTW, this is what good power should look like.

[davidz71]

azflycaster,
That is the exact duplicate of what I have. All my kids are in for Mother's Day and one was to sleep in the trailer last night. I noticed when straightening things out for him to sleep in the back bed that the 110 v. power was at the top of the green and at the edge of the red (128 volts). I do have a Hughes Autoformer but I have never seen it this high.

[Jim Clark]

Is it a LED or a Neon bulb ? Is it flat topped ? Mine is Neon and they tend to just fail. If you do a little research you can come up with the circuit as it is very common on boats also. I built a panel years ago and found the circuit on the internet somewhere.

Of course I normally know when shore power is on, the blinking microwave gives it away.

Good Luck Jim