Beating a dead horse IVR QUESTION

[kewen300]

1966 Barracuda.

Does the IVR have any effect on the rest of the dash? Recently my fuel gauge stopped working but the rest of the dash was working properly. Last night driving my car home. The temp gauge will not go above the cold line. While running and the oil pressure will not go above the first thick line on the low side. When the car is shut off the temp and oil gauge will dropp all the way down. With only the power on in acc. Mode the temp needle move from the base position to the cold line. Is this all a sign that the IVR failed. Or are their underlying issues?

 

[RustyRatRod]

Do you know if the IVR is in the fuel gauge? It is on my 64. If it is on your car, then I'd say the answer to your question is a probably a strong yes.

 

[RedFish]

If needles move at all they are receiving some current. I would guess instrument voltage limiter to be the fault whether in the fuel gauge or not.
Of course guessing is not diagnosing. You must get proper 12 volts in it if it is the original mechanical limter. Modern solid state regulator will function fine on 9 volts supply.
With early A you should do something soon. Too many times their limiter circuit would fault some where and copper trace on circuit board served as fusible link. Burned off the board and in two. Bad can get worse.

 

[toolmanmike]

EDIT: "Except Barracuda" 66 Darts had the plug in regulator, not the Barracuda's according to the Layson's catalog. @RustyRatRod, having a Layson's, TRW performance, and a few Filko Ignition catalogs is like I was back at the parts store. Fun stuff.

 

[RedFish]

66 barracuda should have 3 post fuel gauge. Plymouth did this much more and longer than Dodge. I've been wrong before though.

 

[RustyRatRod]

66 was not part of the fuel gauge according to the Layson's catalog. They are the common plug in style. @RustyRatRod, having a Layson's, TRW performance, and a few Filko Ignition catalogs is like I was back at the parts store. Fun stuff.

Thanks Mike! I wasn't sure. Yes, I flip through my "library" frequently. lol

 

[RedFish]

I was just about to Google images for that circuit board but,,, I'll stand corrected on that part. Images of copper trace blistered off early A boards have been seen here several times.
Carry on

 

[kewen300]

As far as I've researched the 66 barracuda has the limiter in the fuel guage. I've had this dash apart before and located no external limiter. Also if I have my information correct based on previous posts. To install the external i just need to cut the wire inside the fuel gauge then hook a lead from each finger of the external limiter to the lugs on the the fuel gauge? However does it matter what side goes to which on the limiter and the guage is marked with S V I on the lugs. Which lug goes to which side?

 

[toolmanmike]

As far as I've researched the 66 barracuda has the limiter in the fuel guage. I've had this dash apart before and located no external limiter. Also if I have my information correct based on previous posts. To install the external i just need to cut the wire inside the fuel gauge then hook a lead from each finger of the external limiter to the lugs on the the fuel gauge? However does it matter what side goes to which on the limiter and the guage is marked with S V I on the lugs. Which lug goes to which side?

I believe you're right. 66-74 all A body except Barracuda. I just saw another listing in the catalog.

 

[MOPAROFFICIAL]

Ivr, instrument voltage regulator. People tend to call it a voltage limiter because it actually does lower the voltage

 

[Bennoel 10]

I thought IVR stood for intermittent voltage regulator ? I was under the impression that the original units were mechanical. Similar to ignition points. They pulsate. This is why the gas guage doesn't behave like a windshield wiper when driving and gradually climbs up.
Also I believe it reduces the voltage. When they fail the guages actually read higher than they should. After a period of time ( unknown exactly) they can burn out or fail causing heartache and $$. I was lucky to catch it before big damage. I replaced with modern electronic IVR. This is the conclusion I came to. Others are free to clarify or denounce my beliefs.
Wish you luck

 

[MOPAROFFICIAL]

I thought IVR stood for intermittent voltage regulator ? I was under the impression that the original units were mechanical. Similar to ignition points. They pulsate. This is why the gas guage doesn't behave like a windshield wiper when driving and gradually climbs up.
Also I believe it reduces the voltage. When they fail the guages actually read higher than they should. After a period of time ( unknown exactly) they can burn out or fail causing heartache and $$. I was lucky to catch it before big damage. I replaced with modern electronic IVR. This is the conclusion I came to. Others are free to clarify or denounce my beliefs.
Wish you luck

It can stand for whatever you want it to... like... imbecile voice reducer ...or independent vampire rapist ...

Good luck with whatever you call it.

 

[Bennoel 10]

It can stand for whatever you want it to... like... imbecile voice reducer ...or independent vampire rapist ...

Good luck with whatever you call it.

I like, independent variable reports ??
Lol.

 

[RedFish]

Uggg, the mechanical unit was referred to as instrument or gauge voltage limiter. Most everything that changed from 6 volt to 12 volts had to have one to limit how much of the 12 volts reached the same 6 volt type thermal gauges. GM was 1 mfgr that switched to 12 volt instruments.
Once again, no one needs to open a fuel gauge to effectively disable a internal limiter. Simply lift the instrument from the metal housing and interupt the limiters ground. A piece of tape works.
In most examples the switched 12 volt supply (typically blue w/white tracer) serves only the limiter. It's nolonger needed or wanted in any gauge. Pull it from the cars harness connector and route it to what ever modern solid state regulator you choose wherever you choose to place it.

 

[Vaanth]

1966 Barracuda.

Does the IVR have any effect on the rest of the dash? Recently my fuel gauge stopped working but the rest of the dash was working properly. Last night driving my car home. The temp gauge will not go above the cold line. While running and the oil pressure will not go above the first thick line on the low side. When the car is shut off the temp and oil gauge will dropp all the way down. With only the power on in acc. Mode the temp needle move from the base position to the cold line. Is this all a sign that the IVR failed. Or are their underlying issues?

View attachment 1716462235

View attachment 1716462236

The behavior of all three gauges -- fuel, temperature, and oil pressure -- of reading similarly low points to the gauges' voltage source.

The fuel gauge, temperature gauge, and oil pressure gauge, all receive their power from the voltage limiter, also called the instrument voltage regulator and other terms. The Chrysler term is "voltage limiter".

The voltage limiter, internally, though bimetallic heating and cooling acting to open and close contact points, provides an effective voltage of five volts to the gauges. This is a pulsating voltage, and associated current, which is not a solid DC voltage, but effectively averages at five volts. The gauges themselves use a similar heating and cooling effect as the voltage limiter to drive the gauge indicator needle which corresponds to the resistance level of the associated sending units -- fuel, temperature, and oil pressure. The voltage limited source, the gauge, and the sender resistance form a series circuit calibrated to indicate the value or fuel level, engine coolant temperature, or engine oil pressure. The gauge range of these parameters were designed for level indicators to correspond to the same resistance values.

With all three gauges reading low, the effective voltage, and associated driving current, to the gauges is low, but not (yet) zero. This low voltage limiter output is due to one of the following issues:

• Full +12 volt input voltage to the voltage limiter is low due to a bad connection.
• Full +5 volt output from the voltage limiter is not reaching the gauges due to an output connection issue.
• Voltage limiter contact points are corroded or dirty, reducing the output.
• Voltage limiter internal heating coil or bimetal strip is weakening.
• Voltage limiter ground connection is poor. The limiter is grounded to and through the instrument cluster ground.

Most vehicles have a separate voltage limiter that is external to the gauges and plugs into the instrument circuit board or via leads. Others, including the 1966 Barracuda, incorporate the voltage limiter into the fuel gauge.

The following image diagram shows the voltage limiter, fuel gauge and sender for cars with the separate voltage limiter:

The following image diagram shows the voltage limiter, fuel gauge and sender for cars with the voltage limiter incorporated in the fuel gauge:

In both cases, the temperature gauge and oil pressure gauge (if equipped) is powered by the same five volt output from the limiter and connect to their respective sending units.

 

[RedFish]

Fismrst thing this morning I find another fault on this minister of misinformation that AL Gore claimed to create called internet. The Pic I provide come from for sale postbhere at forabodiesonly. I'm sure you all can see as well as I do that there are no provisions for a plug in type regulator. You will notice 3 holes in triangle formation. Those are for a 4 post dual function instrument. NOW ,
Search web vendors images of same circuit boards and scratch your head. There are no provisions for a plug in type limiter. 1 of the 3 holes for the fuel gauge doesn't appear to be drilled through. Does their package sat "some assembly req'd? Drill ad needed? Do they demand owners use a different gauge and their outboard regulator? Maybe just crap for pictures?
(sigh with exhale here) Just wtf?
I really frown at myself in my mirror when I seem to use a members thread as my own soapbox like this. I think somebody ought to. If I could ever gets my hands on that Rick Erinburg guy that 1st published the open gauge, bend thingy BS, I would choke him out!

 

[kewen300]

Welp, it appears my cruising season is over. Tore the dash down and installed a spare fuel gauge I had. The original one had the wire for the gauge broken and the other issues with the limiter. I picked up a limiter from classic industries(complete junk) hooked it up everything worked as it should. Proceeded to put everything back together started the car and smoke started from either the temp gauge or fuel gauge and all the gauges pegged. Tore the entire car back apart. This is what I saw.

It appears the pin for the fuel gauge is burned.is there anything that looks wrong from this photo that maybe im not seeing?

I ordered a rte limiter and will be ordering a new board. As more than a couple of the pins are loose and cracked. Also should I clean up the ring terminals so they dont touch any other part of the circuit board or doesn't it matter?

Thanks

 

[RedFish]

Aftermarket replacement boards have shorter pins soldered to the copper trace. Both good and bad for reasons I won't go into right now. Everything has a downside.
If you install a modern solid state regulator you can toss that noise cap into a place where you can find it again. Solid state doesn't make noise but,,, that #10 booted 90 degree terminal isn't easily sourced. Save it for fuel sender, temp sender, etc..
I alway recommended put a nut on the stud then the ring terminal toothed washer and a second nut. Lifts terminals well off adjacent traces. Yours is the 4th or 5th fuel gauge renew I would have declided since my return here (June I think). I do wish you better luck though.

 

[kewen300]

That was going to ne my next question. Would it be better to use the caps instead of the ting terminals? And where do you find such a wire. Also need to find a board with the third hole.

 

[RedFish]

That was going to ne my next question. Would it be better to use the caps instead of the ting terminals? And where do you find such a wire. Also need to find a board with the third hole.

Don't know what you mean by "caps". If you mean the 90 degree push on terminals, you would have a hard time finding. #8 is easily sourced. Not #10 though.
Images can be deceiving. If the 3rd hole really isnt there and the proper trace is, 7/32 drill bit would work.

 

[kewen300]

Thank you and everyone else for all your help. Hopefully the new limiter and new board will solve some issues. Just wish I didn't have to wait on parts this close to end of season in NY.

 

[RedFish]

Bought my current 67 B'cuda out of Seattle 2006. 4 differnt plane rides to get there on Oct. 8th. 2854 miles, from his driveway to mine, 3.5 days. Nothing but gas and a lot of coffee. Perfect time of year to be on the road. Heat on high with window down all night long.
Years ago we drove our 1st 67 fish for about a month without the instrument panel while I was working on it. Headlight switch and wiper switch attached to screw holes with plumbers strap. Heater control tied up with stiff wire. It can be done.

 

[Mattax]

The pins can be fixed or maybe in this case better to replace. One of the members here does that for very reasonable price. If the rest of the board is in good condition that would be an option and then not have to wonder what the aftermarket board got wrong.

Think of it this way. Nice weather to work on the car too. Winters in NY can be rough unless you have a large heated and well lit garage.

 

[toolmanmike]

Bought my current 67 B'cuda out of Seattle 2006. 4 differnt plane rides to get there on Oct. 8th. 2854 miles, from his driveway to mine, 3.5 days. Nothing but gas and a lot of coffee. Perfect time of year to be on the road. Heat on high with window down all night long.
Years ago we drove our 1st 67 fish for about a month without the instrument panel while I was working on it. Headlight switch and wiper switch attached to screw holes with plumbers strap. Heater control tied up with stiff wire. It can be done.

Love that story!

 

[jeff alder]

Bought my current 67 B'cuda out of Seattle 2006. 4 differnt plane rides to get there on Oct. 8th. 2854 miles, from his driveway to mine, 3.5 days. Nothing but gas and a lot of coffee. Perfect time of year to be on the road. Heat on high with window down all night long.
Years ago we drove our 1st 67 fish for about a month without the instrument panel while I was working on it. Headlight switch and wiper switch attached to screw holes with plumbers strap. Heater control tied up with stiff wire. It can be done.

That brings back memories. My neighbor Darrin and I went to Uniontown PA to get a 67 Barracuda convertible for Karrin. We had his old beat up Dodge pickup and an enclosed car hauler for his dirt tack car. If you want to take a trip with no scenery this is the one. 10 hours later we were in the middle of Yogi Bear State Park looking for Moparker's house. Down a very steep but nice concrete driveway was a nice garage away from the house. It was dark out but there he was waiting in the garage for us. We got it loaded with all the extra stuff he had for the car...which was a lot...again thanks to you Moparker. I offered to take Darrin for a nice steak and lobster dinner, a few beers of course and then the nearest motel Moparker could recommend. Nope...Darrin opted for a Kentucky fried chicken dinner to go ,turn around and back to Illinois we go...LOL The car had great bones and was EXACTLY how it was described. Someone had painted the dash (before Moparker) a hideous purplish/blue and changed all the original Mopar gauge faces to the white ones on EBAY. Thanks to 67Cudman we have a super nice Canadian replacement woodgrain dash. Someone else here had a a 1968 150 MPH speedo retrofit with 67 guts for the screw on cable. We found a nice working original tachometer at the Indianapolis swap meet. I havent driven the car without the dash...Redfish...but I would. LOL We did drive it a bit before I tore all the dash apart but we could only go about 10 blocks on the peanut jar gas tank Moparker had rigged by the radiator. He was in the process of putting rear quarters and the dual cutaway rear lower valance on the car when we bought it so the gas tank was in the trunk! Anywho we made it back to Illinois on 16 ounce Mountain dews from the truck stops along the way as they were the only thing open. I have 3 dashes torn apart on Karrins dining room table right now making one out of 3. NO WHITE FACES! I could have never done all that plane hopping like you did Redfish but never try and keep a Mopar guy from getting a car home even if it is on the other side of the country.