Got stranded at Wally World

[Slow Left]

Remove the actual wires from both dome switches. Then check again.

I'm with you on this line of thinking...but I'm wondering if there is an easier way to test all the Dome switches...

Nick, next time you are set to work on this a bit, I've got a couple measurements for you take.

They are Voltage measurements and intended to identify (for both the Dome and Cig fuses) which side (either Drivers Side (DS) or Passengers Side (PS)) of the fuse is touching the 'hot' (12V+) electrode at the fuse box.

To run this test, you need to:
plug the Black DIMM (Digital Multi Meter) lead into the common ground port on the DIMM
plug the Red DIMM lead into the "V Ω mA μA" port on the DIMM
Turn the dial on the DIMM to measure 20V DC (not AC)...here's the symbols for how you will tell V DC from V AC:

Once you have the DIMM set up properly, to run the test you will have to:
Have the battery cables attached to their proper battery terminals (don't have to tighten them all the way down, just make sure they are making good contact)
Remove the Dome and Cig fuses from the fuse box (remember which goes in which slot...or just do one at a time so you don't have to remember).
Ground the Black DIMM probe to a big hunk of metal...like the door jam...it is better if it bare metal, not painted, but if it is painted, you can just push through a little with the sharp tip of the probe so that it makes good contact.
Then, with the Red probe touch the DS contact in the empty fuse slot where the fuse used to be.
Write down whether it reads 12V or 0V
Then, move the Red probe to the PS contact in the same empty fuse slot...while keeping the Black probe touching ground.
Write down whether it reads 12V or 0V.

Do this for both the Dome and Cig fuse slots and post up which side (for each) reads 12V and which side reads 0V.

 

[Cruiserdrew]

I'd look for someone tapping power off the dome circuit-like for an aftermarket stereo, cruise control or alarm. Abraded wiring can do this, but usually that will just short and pop the fuse.

If I remember there is a whole bunch of stuff on the dome circuit and you'll need to look at all the wiring and every device, but, aftermarket add ons-look for power taps and splices-are the most likely.

One other thing-do not buy a new battery until this is fixed or it will end up like the battery you have now in short order.

For Slo left-all the USA FJ62s came with a double DIN stereo from the factory.

 

[Slow Left]

For Slo left-all the USA FJ62s came with a double DIN stereo from the factory.

OK. Thanks. Then if Nick replies back that the factory stereo has been removed, then that is a red flag that at some point an aftermarket stereo was installed and removed...and that there might be a constant 12V+ wire (for the station preset memory) loose and grounding somewhere...

 

[2mbb]

When I purchased my Australian-spec inclinometer with clock, it needed two power wires, one that is switched (from the "acc" circuit on the ignition switch) and one that is always on (from the dome light). The switched power is what triggers the clock digital display to turn on/off. The always on power keeps the clock timer running. Presumably the clock timer draws less power than the digital display, that is why they differentiate between the two. There was also another wire coming from the headlight switch, I think. This would actually dim the digital display when the headlights are on...it seems pretty complicated for a simple clock feature...

 

[Slow Left]

When I purchased my Australian-spec inclinometer with clock, it needed two power wires, one that is switched (from the "acc" circuit on the ignition switch) and one that is always on (from the dome light). The switched power is what triggers the clock digital display to turn on/off. The always on power keeps the clock timer running. Presumably the clock timer draws less power than the digital display, that is why they differentiate between the two. There was also another wire coming from the headlight switch, I think. This would actually dim the digital display when the headlights are on...it seems pretty complicated for a simple clock feature...

OK, I think I understand.

The wire below I labeled with the question marks must be a variable voltage from the Tail fuse circuit...controlling the brightness of the Digital Clock display by raising the potential on the ground side (to reduce brightness) with the Lights ON and lowering the potential on the ground side (to increase brightness) with the Lights OFF.

12V+ constant is through the Dome circuit (which is not through the Ignition Switch, so it is always 'hot' even with Engine OFF/Key OUT) and is for clock memory.
12V+ switched is through the Cig circuit (which passes through the Ignition Switch, so it should only be 'hot' with Key IN and on ACC or ON (Engine running)) and supplies the larger amount of power to the Digital Clock.

 

[Slow Left]

@2mbb, so if there is a leak through the Digital Clock, somehow there is a short inside the clock that is allowing current from the 12V+ Constant to see a ground that it is not supposed to be seeing.

 

[WhompinFJ]

I'm working today, I'll be home a little past 4 and I will be ready to get this narrowed down. Stay tuned

 

[WhompinFJ]

Work got done early I'm on my way home, I'll start with the 20v dc test in the fuse slot.

 

[WhompinFJ]

Ok guys too hard to get a picture but for the dome light it read 12.48 volts, and the cig it read the same 12.48. This was on the left side for both, the right read 0

 

[WhompinFJ]

Put all fuses back in and removed the whole rear light assembly and got this reading. That tells me the big problem is in the rear

 

[Slow Left]

Ok guys too hard to get a picture but for the dome light it read 12.48 volts, and the cig it read the same 12.48. This was on the left side for both, the right read 0

Dome fuse slot
DS - 12.48 V
PS - 0V

Cig fuse slot
DS - 12.48 V
PS - 0V

Was the key out of the ignition when you took these readings?

 

[WhompinFJ]

Yup key out

 

[Slow Left]

Alright.

We're gonna do a Continuity Test with the DIMM...meaning we are going to check for a 'short' along a circuit where (in this case) a switch (in this case the Ignition Switch) is supposed to be open (OFF).

To do the Continuity Test, we are going to let the DIMM generate the current, so both battery cables need to be detached from the battery...

Once you have removed both battery cables from the battery, set the dial on the DIMM to this:

With the Dial set for Continuity, if you touch the end of the two probes together, the DIMM should make a sound...indicating that the current the DIMM is generating on one side of is able to travel along a closed circuit path to the other side....the sound indicates that the circuit is complete.

 

[WhompinFJ]

No beeping just this, and man I love these gator clips!!!

 

[Slow Left]

With:
Both battery cables removed from the battery
Key OUT of Ignition
Cig fuse removed

Then:
attach one probe lead to the DS fuse slot (the one that read 12.48V)
On the other probe lead, you are going to attach a long 'jumper' wire...an insulated wire that will act like an extension of the probe so that it can reach the end of the pos battery CABLE (NOT THE POS BATTERY POST)
Now, the tip of that 'jumper' wire is your probe tip...and when it touches the end of the pos battery cable, let me know if the DIMM makes a beep or not...and if it doesn't, what is the number value shown on the screen of the DIMM.

 

[Slow Left]

Did the DIMM show a number? What was the value of the number?

 

[WhompinFJ]

Jumper wire hooked up to the positive lead, then I hooked it into my meter on the negative end and put the red lead into the left side of the fuse socket and it beeped!

 

[Slow Left]

View attachment 1105105 Jumper wire hooked up to the positive lead, then I hooked it into my meter on the negative end and put the red lead into the left side of the fuse socket and it beeped!

End of Positive Battery cable - jumper wire - positive lead on DIMM - DIMM - neg lead on DIMM - DS of empty Cig fuse socket...

...and it beeped. Does the DIMM also show a number?

 

[Slow Left]

Well, I guess never mind about the number if it beeped...because according to the manual, it will beep if the Resistance is less than 100 Ohms.

And the Resistance of that circuit should be infinity Ohms because there should be no current allowed to flow through it with the Ignition Switch open (Key OUT).

 

[Slow Left]

We might have to come up with an additional test on the Ignition Switch...somehow the Cig circuit is getting power it should not.

EDIT: because I'm not sure if the only way for that circuit to be closed is through the Ignition Switch. That is the way it should be, but there might be another component other than the Ignition Switch that is failing and letting current pass...