Got stranded at Wally World

[WhompinFJ]

Far left hatch closed

 

[Slow Left]

Hmmmm....I was trying to isolate the rear hatch switch...but I think this isn't the right way to approach that.

You are getting power to both the Dome and Rear Cargo light switches...it is unlikely that the short is between the Dome fuse in the fuse box and each of those two switches. I say unlikely, because a 'beep' on the Continuity test tells us that enough current is getting there for the DIMM to take a reading.

The problem I'm trying to solve is to test for a leak at or on the far side of each of the switches.

 

[WhompinFJ]

So how do I go about doing this?

 

[Slow Left]

Rear Hatch Open
Switch to the L: no reading
Switch to the middle: 5.8 kilo Ohms
Switch to the R: 5.8 kilo Ohms

Rear Hatch Closed
Switch to the L: 5.8 kilo Ohms
Switch to the middle: 5.8 kilo Ohms
Switch to the R: 0.33 kilo Ohms

The middle one is "OFF"...so we expect to see this high Resistance

 

[Slow Left]

So how do I go about doing this?

That's what I thinking on...

I'm trying to rule out the Interior Lights in order to move on to the other circuits, I think I've got the incorrect tests to rule out the Interior Lights still.

 

[WhompinFJ]

What do you mean by incorrect?

 

[WhompinFJ]

Like what would be the correct way?

 

[Slow Left]

 

[WhompinFJ]

View attachment 1105366

Little explanation please?

 

[Slow Left]

Like what would be the correct way?

I think the correct way is start by moving the multimeter to the Rear Cargo switch.

We know that the path between the Dome fuse slot and the switches is not shorting...so no need to keep the DIMM so far away...that is giving high Resistance values.

Little explanation please?

Ha, ha...yeah, these electrical problems are zingers..make me think...

 

[Slow Left]

Keep the Dome fuse out, but disconnect the DIMM lead on that homemade 'tool' and reconnect that lead to the R-B wire at the Rear Cargo Light switch (where #1 arrow is pointing...where you are pointing to in post #186)

Sorry, you're going to have to pull the light switch back off the roof.

 

[WhompinFJ]

So I disconnected the meter and put the red lead on the RG tab for the bulb and connected the common to the strut on the tailgate and the readout is 6.12 kilo ohms with the hatch open and the switch in the left position

 

[Slow Left]

So I disconnected the meter and put the red lead on the RG tab for the bulb and connected the common to the strut on the tailgate and the readout is 6.12 kilo ohms with the hatch open and the switch in the left position

OK, gonna have to run through these scenarios again...

Hatch Open
Switch L:
Switch Middle:
Switch R:

Hatch Closed
Switch L:
Switch Middle:
Switch R:

 

[WhompinFJ]

Ugh! Ok I'm eating dinner so give me a sec

 

[Slow Left]

Yep. No worries.

I'm probably gonna sign off here in a bit...but I'll check back in tomorrow again.

The thing that is really sticking in my mind is that we saw 12V at the Cig fuse when, according to the circuit diagram, we should not...because the only time the Cig circuit should get 12V is when the Key is in the Ignition and ON...the Cig cirucit is 'switched' through the Ignition switch.

I'm trying not to make any assumptions on where that 12V is coming from, but I am assuming, since it was on the same side of the fuse slot as the 12V on the Dome switch, that it is coming from somewhere in front of the fuse...not behind it. I'll have to take another look at the wiring diagram and we might have to find a way to know for sure which side of the fuse slot is which.

On these Interior Lights...still inconclusive...

 

[WhompinFJ]

Ok. Same reading with all switches whether hatch is open or closed

 

[WhompinFJ]

No problem man! Thank you for all your help so far, I'm currently puting a tool set together right now so no worries.

 

[Slow Left]

No problem man! Thank you for all your help so far, I'm currently puting a tool set together right now so no worries.

You bet.

Here is what I think is bothering me about the inconclusive results of these tests on the Interior Lights.

The Continuity test on that DIMM has a threshold of 100 Ohms. So, if the DIMM can send out and then receive a current with less that 100 Ohms resistance, it will beep.

The 'leak' from the Dome circuit (when you had the DIMM installed inline between the neg battery cable and neg battery post) was 0.5 A (or 500 mA)...and the leak from the Cig circuit was 0.08 A (or 80 mA).

This means, we are looking for a short on the far side of the Dome fuse slot that is 0.5A.

According to the manual for your model DIMM, the max open circuit voltage value that the DIMM puts out is 3 V. So, doing the math:

3V = 0.5A x R

then R = 6 Ohms

The magnitude of the leak we are looking for (in terms of Ohms) is a 6 Ohm increase from the circuit operating normally...well within the 100 Ohm upper limit of the DIMM.

This is why I'm not convinced that the tests we ran on the Interior Lights are in anyway conclusive...even if I knew what the value of a properly functioning circuit is, the error in how I'm taking the measurements is too great.

 

[WhompinFJ]

Yeah. I'm gonna talk to my dad about it and see what he says, all this is confusing

 

[cruisermatt]

So can I be next in line for a full electrical diagnosis?