Cluster Question (again):

[Captain D]

Hi all,

Still trying to get the gauge cluster right. In short, I had the alternator gauge rear mounting hardware bolt replaced (threads were lil' stripped). However, the needle wants to lean into the negative side, plus, it jiggles all over the place so that it's nowhere near a correct reading when the Charger is on. On top of this, now the oil pressure, fuel, & temp gauges are non-moving / pegged hard to the left.

The shop was just supposed to have swapped out the mini alternator gauge bolt on the back, but neither that gauge nor the remaining mini gauges on that panel work. I don't believe that it's the cluster regulator because the wiper, lights, flashers, & clock all still work fine. I was supposed to drive the car 15 minutes up the road for a weekend event and although I'm sure everything mechanically is fine to do so, it's not knowing without functioning gauges even if it's only up the road...

[b5blue]

That white frame grounds through the dash screws. The green board contact areas can be fussy from age. Did you install a new solid state type 5 volt do dad or do you have old original style? (Newer type has voltage breaker.)
That's about all I can tell ya, good luck!

[Nacho-RT74]

Cluster limiter is just for the oil, temp and gas gauge... rest gets its own sources. This limiter should get also not only 12 volts but also be correctly grounded, because if not, will send full 12 volts and gauges will burn

Amm needle sould be attached to the brass plate which moves with magnetic field changes while load is changing the magnetic field direction on magnet. These pieces are not glued just put one over the other one, so maybe needle is not correctly in place with the moving plate I'm talking about

[Captain D]

Thanks gents! Yeah, I too was thinking a grounding issue. If I go anywhere w/ the car, I'm probably best disconnecting the wiring out of preventing gauge burnout.

I checked grounding, but everything appears to be tight & clean. The shop keeps saying that it's something wrong on my end, but I honestly feel that, though they may bench test the cluster at their shop & it checks out fine, they didn't assemble it correctly. I've removed the cluster before they 'restored' the alternator gauge & never had an issue...

[b5blue]

If it "benches" okay check all your old connections in the car. Are you using Caig Labs De Ox It? (Stuff is gold for old car wires and connectors.)
   https://caig.com/      I use this everywhere not just the car.

[Captain D]

The shop 'claims' that it passes the bench. But, if problems persist, I could always pull it & have them test it while I watch & wait,

[Captain D]

This is where the ammeter gauge needle now rests all the time since the gauge was 'repaired.' The cluster is currently out of the car and either in / out of the car, this is it's new spot (leaning into the negative zone). And, all the mini gauges to its left are completely pegged to the left at '0' dead in the water, as well. Previously, the needle was exactly at '0' when the car was turned off. And, naturally, when at the 'on' position, slightly read into the negative until the car was turned on and it always ran ever so slightly to the right. Now, it's always in the negative and jumps around like hell - nowhere near accurate by any means, yet the shop says that this is normal. Uh, I don't don't think so...

I also checked all connections - nothing is singed, dark, loose, etc. Plus, the tabs where the mounting screws go into (that secures the cluster) are all squeaky clean / shiny / no rust for solid grounds. I just know my car and this gauge just doesn't seem right. An off question, but maybe an important one coming from an amateur here, but what is the correct way for the shop to test my cluster? In other words, their way and the correct way to test for this type of cluster may be two different methods to properly test it. I just can't see how, or why, they test it and it comes up as 'normal' like this.

Thanks again for any and all responses.

[Captain D]

Another shot:

[Nacho-RT74]

check the gauges with a 1.5 volts batt or two 1.5 batts in series to get 3 volts between both gauges studs... or a cellphone charger which is around 5 volts. The needle must move. That will tell you gauges are good and problem is anywhere else. Can be checked with a 9 volts batt too, but just a second or two, because more time can burn them.

voltage limiter can be checked with your car batt.... feeding 12 volts and checking pulsating signals on output with a test lead/light or an analog multitester on DC function. That won't tell you limiter is propperly calibrated to provide 5V RMS but just in working order ( same to the gauges ).

about ammeter... will make a draw to explain what it could be happening.

[Nacho-RT74]

this is how the needle is set on ammeter ( more less ).

The yellow triangle is a counterweight which moves with magnetic variations when loads gows through the shunt with the magnet attached. Being a counterweight it tends to be of course vertically indexed. If you tilt up the cluster ( or gauge ) the needle ( red triangle of course with the needle ) will move accordingly to the counterweight indexing as far the magnet also allows that

needle and counterweight are set one over the other with no gap in between. If they are not matched you could read like your ammeter is while in rest position. That's easy to fix just matching the needle with the counterweight back

is just a theory I have about what could be happening.

on second pic a rear view of the ammeter trying to show you that area ( althought upside down )

[Captain D]

Thanks man! Yeah, any & all info that I can relay onto the shop to help them the better as they're convinced that the gauge(s) are fine. I certainly appreciate your time & info once more, my friend.

[Captain D]

The shop noted that the gas, oil, & temp gauges aren't connected to ammeter gauge in any way whatsoever. If there is any issue, it's the voltage regulator on the back of the cluster could be causing them to be nonresponsive, they're saying. It wasn't a cheaper VR, so they may have burn it out. Who knows, but I just want to get to the bottom of this. Any insight into their response would be awesome (just to compare). Thanks again...

[Nacho-RT74]

Sure all three gauges are conected to ammeter. Ammeter gets its own life, and the other three conected with to the VL for positive voltage. Ground is wired independiently to each gauge from senders. VL is sourced in some cars from ACC circuit and on some other from RUN circuit, but allways keyed.

Expensive VL ? did you get the electronic RTE piece ?

Ammeter just gets positive in both ends to monitorize the loads leaving and returning to the batt.

[Captain D]

Correction:

Yes, purchased this unit:

https://www.rt-eng.com/index.php/RTE_limiter.html

Just to double-check, are you saying that the alternator gauge can or can't affect the gas, oil, & temp gauges readings? If they're non-functioning, more than likely it's primarily the voltage regulator that needs replaced, is that correct?

What doesn't make sense is ~ if the voltage regulator was shot, then how did it successfully pass the bench test then as being supposedly 'fine,' is what I'd like to know from them...

[Nacho-RT74]

Just to double-check, are you saying that the alternator gauge can or can't affect the gas, oil, & temp gauges readings? If they're non-functioning, more than likely it's primarily the voltage regulator that needs replaced, is that correct?

yes... amm gets its own life appart from the rest of the cluster. The missread on the ammeter must be a "mechanical" issue as explained. The ammeter is a gauge really hard to beat.

What doesn't make sense is ~ if the voltage regulator was shot (which, may have been their fault in damaging it), then how did it successfully pass the bench test then as being supposedly 'fine,' is what I'd like to know from them...

can't tell it.

Did you check the gauges one by one with a battery as explained? just to confirm gauges are still on working order.

[Captain D]

Hey Nacho - thanks man for the many responses as you've been great! Update:

- The entire gauge cluster, including the voltage regulator, tested out working perfectly fine 100% across the board during a bench test.

Reoccurring problem: when the cluster sits atop any common table the alternator gauge needle sits practically '0' (see pictures below), which looks good during a bench test, sure, yet when the cluster simply rests in the dash of the car with absolutely nothing hooked up, the needle leans into the negative when it's supposed to be at '0' or ever so slightly to the right. If I hook up all the connections and fire up the car, the alternator needle jiggles like crazy (certainly not accurate) and it's affecting the other 3 gauges (oil, gas, & temp). Check out picture comparisons below.

And lastly, I think that you may be on to something there Nacho when you shared that diagram & counterweight info as it seems to resemble how my ammeter gauge needle appears now. It's as if, when the cluster is laying back mounted in the car, the needle / gauges lose their positioning and lose connection. We're getting closer to cracking this riddle...

Pic of cluster sitting atop a common table:

[Captain D]

Notice how the needle sags into the negative when simply placed into dash of the car (then, when the car fires up the needle jiggles like crazy and affects the other 3 gauges - even though everything passed the bench test with perfectly flying colors). The needle doesn't seem to be seated properly on its 'axle' ~ kinda like a wheel without all of the lug-nuts installed...