The gauge failure posts cursed my car

[Dana67Dart]

Add me to the failed IVR club.

My IVR lost it's resistance (heater) wire.

Was driving along and WTF gauges pegged.

Turned key off costed to a safe place, reached under dash, pulled out the IVR and finished my drive.

Fuel gauge seems to have survived, sitting at a normal key off place, water temp on the other hand is sitting 20 degrees lower than low, ARRRRG!

It's my own fault, I thought about buying an RT-engineering IVR but thought the OEM IVR has been working fine for 54 years, it will be fine!!!


Just placed an order for new RT-engineering IVR

Will probably use a spair mechanical IVR I have in the meantime.

I checked the bad IVR before taking it apart.

OL ohms between ground and ign post
OL ohms between ground and output post
0 ohms between ign and output

Spare has about 62ohms. Where the OL is above.

When I took it apart everything looked good, but there was still OL ohms on the resistance / heater wire.

I removed the wire and there it was about 1/2 way through the winds it was broken.

Live and learn

 

[1969383S]

Add me to the failed IVR club.

My IVR lost it's resistance (heater) wire.

Was driving along and WTF gauges pegged.

Turned key off costed to a safe place, reached under dash, pulled out the IVR and finished my drive.

Good news for you is Plug in only! Course you know that!

Now for some Contortionists act to change it!

 

[Dana67Dart]

Now for some Contortionists act to change it!

It must have been histerical seeing me on my back under the dash on the side of the road pulling it out. Luckly I have another temp guage, if mine is toast. I'll have to swap out the face plate and calibrate it, oh and pull the cluster.

Not looking forward to that!

But if the cluster is out, time to paint the pointers, clean the speedo, maybe even change our the speedo cable housing. Get that one light bulb I can't reach!

 

[1969383S]

It must have been histerical seeing me on my back under the dash on the side of the road pulling it out. Luckly I have another temp guage, if mine is toast. I'll have to swap out the face plate and calibrate it, oh and pull the cluster.

Not looking forward to that!

But if the cluster is out, time to paint the pointers, clean the speedo, maybe even change our the speedo cable housing. Get that one light bulb I can't reach!

I ponder if it easier to take the front seat/seats out to help that!

Actually I know this to be true for a 58 year old abused body!

 

[RustyRatRod]

Don't tell me, lemmie guess. You got the .5 volt one, didn't you?

 

[67Dart273]

Well my condolences. My first VERY first experience with a gauge regulator was in fall/ winter of 67 before I joined the Navy. had a '60 Ferd Falcoon. Driving down the road, the gauges pegged. Bear in mind I am young not much experience, not sure if I even knew what a gauge regulator WAS. But I was smart enough to realize that TWO gauges had pegged, so had to be a common problem.

At first I thought maybe the generator (NOT an alternator LOL) regulator had stuck. But they pegged with engine stopped. "I think" what I did was just reach around under the dash trying to find something to disconnectt--and may have pulled the IVR out of there accidently I knew immediately what it "had to be." of course they were "cheap" then--until you figure inflation. I think I was earning 2-3 bucks an hour

 

[Dana67Dart]

I ponder if it easier to take the front seat/seats out to help that!

Actually I know this to be true for a 58 year old abused body

I will be doing that if I pull the dash.
My 59 year old body doesn't bend like it used to!

 

[Dana67Dart]

Don't tell me, lemmie guess. You got the .5 volt one, didn't you?

?????????

 

[kursplat]

I ponder if it easier to take the front seat/seats out to help that!

Actually I know this to be true for a 58 year old abused body!

yup, i don't even question it anymore, it's step 2, right after the battery. the IVR has been on my 1st things to do list for awhile now, along with brake hoses, checking wheel bearings, ect, for whenever i get a "new" mopar.

 

[RustyRatRod]

?????????

I apologize. I don't know why I put a decimal point in front of the 5. I meant 5v. That's what everybody uses, but it's technically incorrect. It should be a 6 volt. The reason for that is 6v will make the gauges show half way and that's a good point for calibration. It's also half the total voltage of the battery, of course.

 

[Dana67Dart]

5. I meant 5v

I bought the RT-engineering IVR their claim is that it mimics the OEM mechanical even in the wave form. So we will see.

 

[RustyRatRod]

I bought the RT-engineering IVR their claim is that it mimics the OEM mechanical even in the wave form. So we will see.

I'm sure you'll never see a 1v difference, but it's still not quite right. LOL I've used ona before and it worked well, but I have a glass jar full of the 6v ones and heat sinks. I caught on sale "somewhere" a while back. lol

 

[1969383S]

I replaced all My 69 Fish Gauges with New Charger Specialties gauges and RTE IVR. Never been happier!

 

[harrisonm]

Good news for you is Plug in only! Course you know that!

Now for some Contortionists act to change it!

LOL. No Kidding. Hey, @Dana67Dart, anymore, when I work under the dash, I pull out the seat. The few minutes it takes pulling the seat is more than offset by how much easier it is to lie on your back where the seat was while working under the dash.

 

[67Dart273]

I apologize. I don't know why I put a decimal point in front of the 5. I meant 5v. That's what everybody uses, but it's technically incorrect. It should be a 6 volt. The reason for that is 6v will make the gauges show half way and that's a good point for calibration. It's also half the total voltage of the battery, of course.

Not sure that's true, Rob. "I've been told" that the original IVR was a 50% duty cycle

I'm sure you'll never see a 1v difference, but it's still not quite right. LOL I've used ona before and it worked well, but I have a glass jar full of the 6v ones and heat sinks. I caught on sale "somewhere" a while back. lol

1V is quite a bit of the overall. That is 1/5 or 20%!!!!! If that were 120VAC you are talking about A TWENTY FOUR volt change!!!

 

[RustyRatRod]

Not sure that's true, Rob. "I've been told" that the original IVR was a 50% duty cycle

1V is quite a bit of the overall. That is 1/5 or 20%!!!!! If that were 120VAC you are talking about A TWENTY FOUR volt change!!!

Does a 50% duty cycle = 5v? I don't know how "all that" works out.

 

[j par]

The next time I pull apart the duster this is going in...

It has all it's own sensors, made in USA, 60 foot recall, 1/4 mile recall.
And 25% off on blaçk Friday...

 

[KosmicKuda]

Does a 50% duty cycle = 5v? I don't know how "all that" works out.

As I understand it, and IIRC, the mechanical IVR takes the 12-14 V input and regulates it by going ON-OFF-ON-OFF-ON-OFF-ON-OFF ad infinitum. The average voltage that comes out is about 5V.
Similar to the point type mechanical regulator on the firewall.

 

[RustyRatRod]

As I understand it, and IIRC, the mechanical IVR takes the 12-14 V input and regulates it by going ON-OFF-ON-OFF-ON-OFF-ON-OFF ad infinitum. The average voltage that comes out is about 5V.
Similar to the point type mechanical regulator on the firewall.

Gotchya. What I've read is for test and calibration, companies use 6v. That's why I'm going with it. Makes sense. To me. LOL I'll find out if mine ever bites the dust. So far, it's rockin right along.

 

[67Dart273]

Does a 50% duty cycle = 5v? I don't know how "all that" works out.

No it's simple, but it depends on "are you" going to use 12.6 or 14V? It is simply "half" the voltage. But I don't remember if or when or how that was determined..........did Chrysler every SAY it was 50 or was that just a passing comment? Regardless though, a 1V change at only 5-6V is a lot of change

 

[RustyRatRod]

No it's simple, but it depends on "are you" going to use 12.6 or 14V? It is simply "half" the voltage. But I don't remember if or when or how that was determined..........did Chrysler every SAY it was 50 or was that just a passing comment? Regardless though, a 1V change at only 5-6V is a lot of change

Right, which does make me wonder then, why not use 6.5v or 7v? 5v seems a little low in that application. What am I missing?

 

[KosmicKuda]

I built an ICE years ago

Right, which does make me wonder then, why not use 6.5v or 7v? 5v seems a little low in that application. What am I missing?

I'm gonna say using 5V as a control voltage is kind of an industry standard. Not just automotive.
I built an IVR for my 68 25 yrs ago using a few parts from Radio Shack for less than $5. The chip thing was constant 5V.

I'm a retired Micky though and not a Sparky so I could be wrong.

 

[RedFish]

There are several formulas for electric current. Volts times amps equals watts? Is that correct? My brother is the electronics specialist in my world. So, in the beginning, the instruments were basic thermal range indicators. They were supplied by a 6-volt system and generator. When 12-volt systems and alternators came along, nearly every mfgr produced a gauge voltage limiter that should make these simple 6-volt range indicators work as close as they did before. A short cut to reworking instruments (GM did re-engineer all of them to 12-volts).
The typical 7805 solid state chip will put out 4.8 to 5.2 volts at switch on and climb to 5.4 or more as it heats up. That is what the adequate heat sink compensates for. Without the heatsink, it wont last long. So the basic instrument voltage limiter that supplied fuel and temp only, plugged in and would live at least 10 years (their goal). For the rally panels with a 3rd gauge (oil pressure) feeding from the limiter, some engineer determined, "nope, it won't survive". So they built a more robust limiter and placed it inside a gauge so the standard limiter could not be applied here. Anyway... If you panel has 2 instruments feeding off 5-volts, They might read a hair low, but close enough for range indicators. Back when I was calibrating OEM rally panel gauges (with oil pressure gauge) to run on the 7805 regulator, every dang one of them had to be adjusted a tad.
Bottom line... if you want more exact instrument readings today, the new instrument will operate on 12-volts and have numbers on its screen.
Due to above post, I must add that 7-volts is too much. The gauges will read a good bit above correct and maybe die sooner. Exactly 6-volts is a correct as they can/will be.
These classics are exactly that. We just deal with it. Good luck to all.

 

[Dana67Dart]

Got my rt-eng IVR today.
It will be going in when I'm done with this post.

I did notice something that is funny. The "indicator" they boast about is on the side that faces the cir board so it may not be visible? Maybe a glow from underneath? I will see.
Indicator...

Stock vs RT-Eng IVR

 

[Dana67Dart]

New IVR installed,
(I put Xmas lights on my dart and that means I can not open my driver's door.
There I am in the dark strearched acrosed the hump and my feet sticking up in the air, with my belly jiggling like Santa Clause. What a sight!)


Well the fuel gauge is fine full at full tank.

The temp gauge as I suspected will need replacement. Is reading about 1/2 gauge low.

I tested it with my 10 ohm resistors and my 1 ohm resistors in series to achieve the appropriate low, 1/2 and full readings..

Infrared measurement at the base of the sender