Gauges going all the way on startup + smoke

-
Ivan Baez

Ivan Baez

426 SB daily driver
Joined
Aug 14, 2020
Messages
147
Reaction score
88
Location
Queretaro
Hi, My 69 barracuda is a daily driver. This morning I turn the ignition switch to the ON position and while I waited for the EFI pump to pressurize the system I looked at the fuel gauge to see if I had to stop for gas. It surprised me that it was all the way up because I had not refueled the car in a few days, then I noticed the temp and oil pressure gauges were going all the way up to, while I watched how the temp gauge went off scale (around 5-7 seconds I saw some smoke comming from inside the gauge bezel (around the fuel, amp, oil press and water temp gauges), I turned the switch off immediately and the gauges went back to their normal position. I turned the switch on again and there was no smoke, but still it looked like they were going up again, so turned it off again and drove to work on my SUV instead.

Since all gauges were affected and these are analog electronics it seems like it may be the voltage regulator. Has anyone had this issue?, I have read before that when the regulator goes bad usually gauges are dead, but never going in like-overvoltage condition. Im running all stock gauges and cluster. The regulator looks very old but worked, I have never replaced it.

Thanks for your feedback.

WhatsApp Image 2021-11-16 at 8.47.03 AM.jpeg


WhatsApp Image 2021-07-09 at 8.17.31 PM (2).jpeg
 
This is a classic case of the gauge regulator/ limiter/ IVR going bad. I have not checked lately, RTE does/ did sell an electronic replacement. "If you saw smoke" it is likely that the gauges are toast. You can test them, best done in a mockup situation with a good working IVR in place and resistors to simulate working sensors

67dart273, gauge testing - Google Search

Bench Testing a gauge cluster

This thread may also help but it is old. You will have to click the black icons to bring up the photos

Instrument cluster testing
 
I would suspect the voltage limiter which is built into the fuel gauge on your car. It may be time to remove the cluster.
 
67Dart273 said:
This is a classic case of the gauge regulator/ limiter/ IVR going bad. I have not checked lately, RTE does/ did sell an electronic replacement. "If you saw smoke" it is likely that the gauges are toast. You can test them, best done in a mockup situation with a good working IVR in place and resistors to simulate working sensors

67dart273, gauge testing - Google Search

Bench Testing a gauge cluster

This thread may also help but it is old. You will have to click the black icons to bring up the photos

Instrument cluster testing
Click to expand...

Thanks for the feedback. I hope the gauges still work, after I turned it off I turned it back on and they all moved again, but were heading towards full sweep again, so I turned it off before they reached the limit. In some cases the analog components overheat and toast the outside enamel but still work, Ill cross my fingers because all meters worked fine prior to this and they are the stock ones.

this is the regulator I have (obviously old ):

Screenshot 2021-12-01 110643.jpg
 
Ivan Baez said:
Thanks for the feedback. I hope the gauges still work, after I turned it off I turned it back on and they all moved again, but were heading towards full sweep again, so I turned it off before they reached the limit. In some cases the analog components overheat and toast the outside enamel but still work, Ill cross my fingers because all meters worked fine prior to this and they are the stock ones.

this is the regulator I have (obviously old ):

View attachment 1715829123
Click to expand...

this is outside my cluster, is there another one inside the fuel level gauge as well?
 
If you have that external regulator, it has been added, and the fuel gauge modified, because origininally the Ralley cluster had the IVR inside the fuel gauge. Your fuel gauge should have 3 terminals--1 for 12V in from the key, which feeds the regulator. The regulator output feeds the fuel gauge, and also comes back OUT on the second stud to jumper power to the other two gauges, and the third stud is to the sender
 
If the IVR / instrument cluster is not grounded the IVR provided 12 volts to the gauges.

The smoke MIGHT have been damage but not total failure of the gauges. Only time will tell.

Watch! (Man I love these videos)
 
Last edited:
Looks like you have a '67 dash in your '69, so, I would imagine work has been done in that dash before. A new solid state IVR is in order here to start. The gauges may have survived. Only after you install a new IVR will you know if they work and are still accurate.
 
67Dart273 said:
If you have that external regulator, it has been added, and the fuel gauge modified, because origininally the Ralley cluster had the IVR inside the fuel gauge. Your fuel gauge should have 3 terminals--1 for 12V in from the key, which feeds the regulator. The regulator output feeds the fuel gauge, and also comes back OUT on the second stud to jumper power to the other two gauges, and the third stud is to the sender
Click to expand...

yes, I dont have pictures of the wiring, but you can tell it was added.
 
Dana67Dart said:
If the IVR / instrument cluster is not grounded the IVR provided 12 bolts to the gauges.

The smoke MIGHT have been damage but not total failure of the gauges. Only time will tell.

Watch! (Man I love these videos)
Click to expand...


I will check the ground, it was there last time I saw it because I installed this dash around 3 weeks ago and the car was working fine, I use it most week days to go to work. I had not notice this behavior before, but will check first the three regulator connections before ordering the replacement part.
 
cudamark said:
Looks like you have a '67 dash in your '69, so, I would imagine work has been done in that dash before. A new solid state IVR is in order here to start. The gauges may have survived. Only after you install a new IVR will you know if they work and are still accurate.
Click to expand...

hopefully they were not damaged because it was just a few seconds, but as you mention, only with a good regulator voltage I will be able to tell.
 
Ivan Baez said:
I will check the ground, it was there last time I saw it because I installed this dash around 3 weeks ago and the car was working fine, I use it most week days to go to work. I had not notice this behavior before, but will check first the three regulator connections before ordering the replacement part.
Click to expand...

Interesting info on the video:

upload_2021-12-1_14-17-20.png


upload_2021-12-1_14-18-13.png


upload_2021-12-1_14-18-48.png
 
I agree they are really helpful and easy to follow


Letting the smoke out of electronics is usually a bad thing.

But that they rose again suggest they might have survived.
 
And that plug in type mechanical limiter was designed for the standard instrument panels that had only 2 thermal gauges (their oil was a warning lamp operates on 12 volts). Rally panel has 3 thermal gauges, thus a different type limiter.
So... the outboard mechanical limiter for 2 gauges that someone added to you rally panel will and did work, for a time anyway. You could simply throw another at it and see what happens but... If there is any chance that the sender wire fell off the oil sender and shorted to ground (more common to unpainted aluminum intakes), that would affect all 3 thermal gauges. Diagnosis is always better than throwing money at a problem. And as much as much as the solid state regulator from RTE will cost, it's still the better bet long term. Good luck
 
RedFish said:
If there is any chance that the sender wire fell off the oil sender and shorted to ground (more common to unpainted aluminum intakes), that would affect all 3 thermal gauges
Click to expand...

how that would effect the other guages?
 
RedFish said:
And that plug in type mechanical limiter was designed for the standard instrument panels that had only 2 thermal gauges (their oil was a warning lamp operates on 12 volts). Rally panel has 3 thermal gauges, thus a different type limiter.
So... the outboard mechanical limiter for 2 gauges that someone added to you rally panel will and did work, for a time anyway. You could simply throw another at it and see what happens but... If there is any chance that the sender wire fell off the oil sender and shorted to ground (more common to unpainted aluminum intakes), that would affect all 3 thermal gauges. Diagnosis is always better than throwing money at a problem. And as much as much as the solid state regulator from RTE will cost, it's still the better bet long term. Good luck
Click to expand...

Thanks, will check out the oil sender because I do have an aluminum unpainted intake and the oil sender terminal is not stock, just a spade connector that has disconnected in the past. But I think the wire is not long enough to touch the intake, but will double check for sure.
 
Dana67Dart said:
how that would effect the other guages?
Click to expand...

I'm no whiz at electrical systems, but all three thermal gauges are connected on the 5V side, through a common path on the circuit board. But I don't know what the consequences of grounding the sender lead would be.

I got smoke out of my cluster while bench testing at one point (bad IVR, of course), but the gauges survived. So you might be OK.
 
mvh said:
But I don't know what the consequences of grounding the sender lead would be
Click to expand...
If you ground a sender wire the gauge it is attached to will act like a fuse. The coil in each gauge that heats the bi-metal to make the gauge needle move will get so hot that the coil of wire will fry like a lightbulb filliment or a fuse. The bi-metal might even get damaged from excessive heat.

The IVR will just provide as much current as is needed
 
dash7.jpg

So inside your fuel gauge is a resistor coil on the right. It heats up and breaks contact and cool etc to provide a reduced voltage to your gauges. If the contact stick closed it sends to much voltage and overheats your gauges. the fact u shut it off probably saved your gauges.
 
RTE limiter - rte
These people sell a solid state replacement and have great installation instructions. Did mine 2 years ago, works great. Btw this is a great time to replace your dash lights with leds also.
 
You might have been lucky if it was actually the voltage regulator smoking and not the gauges. Either way, do not put power to it until you get a solid state regulator.
 
dash7.jpg


The coil on the right heats up and breaks contact, cool down and makes contact etc to reduce the voltage fro 12 to what your gauges use. If it sticks it applies too much voltage to your gauges and pegs them. Sorry for the double post
 
You must log in or register to reply here.
-

Back
Top