Big day!

[Waggymcgee]

She has a name!

I replaced the switch a month ago. I actually think brightness has improved. Pictures attached. Not so bad right? I think maybe a bulb is out on the left and turn signal has some bleed through.
I swapped out the window seals today so was able to get her out in the weather. Huge improvement in wind noise!!! Feeling much more confident in how it's running after an hour's drive. The voltmeter gauge is a little bouncy. Imagine that will be resolved with CVR/7805 transistor upgrade.
My little one named the jeep Scarlet, as in Scarlet Begonias....my husband is turning her into a deadhead.
Can't believe how fun it is to drive! I feel like the coolest chick in town and have full conviction that it's better than all these newer jeeps. Don’t burst my bubble!
Pics link:

https://photos.app.goo.gl/cY6U4mb7ZpAXWQgr6

[rang-a-stang]

That is EXACTLY what mine look like.

[Waggymcgee]

That is EXACTLY what mine look like.

Given the level of degradation, I recommend the $17 tool option. I tried to get one out with pliers just to see and it was awful. Nothing to grab onto that wouldn’t snap off or just crumble. Can’t wait to get the panels off and see how rusted it is !

[tgreese]

The 7805 mod only affects the oil, fuel and temp gauges. An '85 should have an ammeter, not a voltmeter. Read about the ammeter bypass in a sticky thread at the top of the tech forum.

Looks good! Dash lights look ok to me. Too bright will affect your night vision.

[Waggymcgee]

That is right Tim. The volts bounce between 12.5 to 13.5 ish, Is that something to be concerned with?

[tgreese]

How are you measuring the voltage? The ammeter won't tell you the voltage.

[Waggymcgee]

I don’t have an ammeter. I have a voltmeter and when running the needle bounces. I believe that range is acceptable, just wondering if the gauge needle bouncing is weird or an issue?

[tgreese]

Should not bounce. Should show a steady 13.5 volts or thereabouts.

The battery potential (chemical potential) is 12.6 volts. The voltage regulator in the alternator senses the battery voltage and adjusts the output current of the alternator up and down accordingly. The extra current through the resistance of the battery raises the battery voltage by Ohm's law. Voltage feedback to the regulator should keep a constant voltage in the system. Typical set point for this feedback is something like 13.5 or 14 volts. 16 is too high, 12 is too low.

The voltmeter is also way out on the end of a bunch of wiring. That wiring will create a voltage drop between battery and the voltmeter, but it should be a negligible drop. If there is extra resistance between the battery and the voltmeter (from corroded connectors or?), a fluctuating load like the CVR could make the voltmeter fluctuate. I would guess that's what's happening.

In that case, replacing the on-off-on CVR with a 7805 would stop the bouncing, but only because the 7805 is a constant load, instead of the on-off-on load.

[letank]

That is right Tim. The volts bounce between 12.5 to 13.5 ish, Is that something to be concerned with?

your voltmeter is one of the recommended modification. So it was done by the PO and there might be a loose wire inside the instrument cluster. The easiest is to use and alternate type of voltmeter, such as a dvm or anything practical that can be used while driving.

I have the same mod for many years and no bouncing, but it was a bit tricky because the hand can stick to the lense , I had to redo mine by adding spacers -nylon washer-

check this post for the 7805

https://www.fsjnetwork.com/forum/viewtopic.php?f=10&t=8334&sid=a5bb8c407f46f0c4444545ac08c4e04b

and this one for the voltmeter swap

http://www.ifsja.org/forums/vb/showthread.php?t=150396

and here

http://www.ifsja.org/forums/vb/showthread.php?t=120103

[tgreese]

If it bounced randomly, it might be a loose wire.

If it acts like it on a timer, (roughly) a second high, a second low, repeat, it's got to be the load of the CVR pulling the meter down.

Also, if the ammeter has been replaced by a voltmeter (ie not the original factory gauge), the installer may have connected it to the same circuit as where the CVR gets power. This will be the worst place to connect it, if the CVR load is causing the bounce.

I put a voltmeter in place of the ammeter my '82 J20, and before I did the 7805 swap, you could see the CVR switching in the meter. It was not much, but the needle would move. There's a lot of only-adequately-sized wire and several connectors between the battery and the dash cluster in these Jeeps. Any resistance between the battery and the meter will make a change in voltage with a change in load. It's Ohms law.

[Waggymcgee]

It

[Waggymcgee]

It is definitely more of a timed thing. One second up, one second down. Yesterday I noticed that it also ticks with the turn signal. All my interior lights (courtesy/dome) stopped working so my electrical issues are not as resolved as I had figured.