so if the gas and temp gauges don't work...

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95teetee

95teetee

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at all (no reaction whatsoever when I turn the key on) but the ammeter still works, is it (or can it be) the IVR?
I'm supposing the ammeter could be independent since it's voltage-related and maybe doesn't go through the IVR like the others, but I'm just guessing there.
 
amp gauge is not on same circuit as the rest. I would say probably IVR. But you appear to be missing a piece of vital information like what year and model. I "assume" the plum 72 w/ regular non-rallye dash which the ivr is separate, but, if not, it may be an internal fuel gauge ivr.
 
Yes but not necessarily the IVR. Could be a bad connection (power) feeding the cluster, or a poor connection right at the IVR. Obviously the quick way is to plug in a new one.

What rocky was talking about, is the earlier bodies (before 66?) had the IVR built into the fuel gauge. Also, all the Rally cluster ones do as well
 
67Dart273 said:
Yes but not necessarily the IVR. Could be a bad connection (power) feeding the cluster, or a poor connection right at the IVR. Obviously the quick way is to plug in a new one.

What rocky was talking about, is the earlier bodies (before 66?) had the IVR built into the fuel gauge. Also, all the Rally cluster ones do as well
Click to expand...
yep sorry should have specified I meant my '72 standard gauge assembly. Is there a quick check for the IVR? (I take it one side would have 12v and the other would have 5)
thanks guys.
 
The original IVR works like a signal flasher. It pulses (breaks) 12V up into approximately a 50% duty cycle pulse, so effectively about half

Some modern replacements are a 5V DC regulator

So if you had an original working IVR, you would see a pulsing voltage on the sender wire, not necessarily 5V
 
67Dart273 said:
The original IVR works like a signal flasher. It pulses (breaks) 12V up into approximately a 50% duty cycle pulse, so effectively about half

Some modern replacements are a 5V DC regulator

So if you had an original working IVR, you would see a pulsing voltage on the sender wire, not necessarily 5V
Click to expand...
I see... does it sound like IVR to you? (again, there's absolutely no reaction in either gas or temp gauge when the key is turned-most of the search results I found mentioned the gauges pegging when the IVR went).
If it's a bad connection like you mentioned earlier, is there something else I'd notice? The gauge lights are working, but I don't know if that's a different circuit...
 
The best way I know to put this is, if you suspect that the IVR is probably an older pulsing unit, replace it with a modern solid state one and go from there
 
95, my understanding of the VR is that it fails with its points closed, so the gauges then get the full 12v rather than the required pulsed voltage. The 12v then cooks the nearly hair-thin thermal wire that is wrapped around the bimetalic strips on the gauges, and the wire burns open. I'd guess both your VR and gauges are toast, but that's just a guess. You should be able to unhook your gauges and put an ohmmeter on them to check if they read open or not.
 
ok...can anyone tell me where exactly power is supposed to be sent to the IVR? It looks like it should be a blue w/white stripe wire @ the 12 o'clock position on the round connector that plugs into the cluster (?).
I have no power there (nowhere on that connector period). I traced that blue/white wire back to a relay up above the kick panel (no power there either, on either side). The other side of that relay has two blue wires, so I'm wondering where the power should actually be coming from...



67Dart273 said:
The best way I know to put this is, if you suspect that the IVR is probably an older pulsing unit, replace it with a modern solid state one and go from there
Click to expand...
tried another IVR, but nothing (as covered above)
 
The blue should be hot with the key in 'run' It is switched ignition. Are you saying it has no power at the wire, or at the PC board. Suspect the PC board pin and harness connector
 
67Dart273 said:
The blue should be hot with the key in 'run' It is switched ignition. Are you saying it has no power at the wire, or at the PC board. Suspect the PC board pin and harness connector
Click to expand...
none at the wire (or anywhere I can trace the wire back-which seems to be to that relay above the kick panel...
edit- no power at the other side of the relay (I guess that's what it is) with the two blue wires going in either.

btw, I ran a wire from a keyed spot directly to the hot side of the IVR, and that makes the gauges work.
 
Sounds like you need a wiring diagram. If you studied the copper trace on the back of your inst' panel you should find the same 12 volts that powers the voltage limiter also powers a couple of lamps at right upper corner. 73 panel is my reference though. 72 may not be identical. 12 volts goes to the middle leg of the limiter. Ground on one side lower pulse current on other side. The middle slot should have a 2nd male terminal poked in there too that comes from the noise suppression cap'. if that is left out connection could be lost.
 
RedFish said:
Sounds like you need a wiring diagram. .
Click to expand...

Download a free service manual here

http://www.forabodiesonly.com/mopar/showthread.php?t=244981

and here

http://www.mymopar.com/index.php?pid=31

MyMopar has simplified but not really complete wiring diagrams but are sometimes easier to follow. They are sometimes wrong, and don't show all terminals and interconnects

Here:

http://www.mymopar.com/downloads/1972/72ValiantA.JPG

http://www.mymopar.com/downloads/1972/72ValiantB.JPG

Here are a couple of partial screenshots out of the 72 Plymouth manual, pages 8-150, and 8-151

Follow from the VOLTAGE LIMITER (12V) over to the harness connector, and out that pin on G5-20 DBL which means arbitrary circuit number G5, no 20 size wire, and it's DARK BLUE off the left of the page. Now look on the other page it comes on the page from the right, goes to "in harness splice" diamond 3, and splices in and goes down to "N" of the bulkhead connector. THIS IS ignition voltage going out to the engine bay

If you were to go back to the no 3 splice, and pick up J2B-12 DBL, this is your IGNITION RUN feed coming from the ignition switch

Pick it back up coming in from the left of the page on 8-151 and you'll see it goes directly to the ignition switch connector

THERE IS NO FUSE anywhere in this circuit, it's only protection is the main fuse link out in the engine bay, which is nearly no protection at all




 
according to that diagram 72 and 73 are the same. So if either of the 2 warning lamps work the 12 volts from switch on is there.
 
just realized the two warning lamps aren't lighting either- hadn't even noticed that until it was pointed out here (too preoccupied with the gauges).

so if I read the schematics right (which is a long shot for me lol) the power comes IN @ connector 'N' on the firewall and splices to the instrument cluster and the ignition switch....so I should be able to trace from the alt. field basically. Unless I'm going completely backwards on the schematic...
 
God dammit. I explained this to you READ what I posted

N is going OUT to the engine. This is "ignition run" from the switch going out into the bay


Somewhere on the interior, between N and the ignition switch connector is splice "diamond 3" in that diagram.

Power comes FROM the ignition switch on the IGN1 line. Read my post above, again.
 
Ya know what? When I first owned these cars there WAS no effin' internet. There WAS nobody to help me out at an instant notice. I had to go down to the dealer, argue with REAL unfriendly parts guys, and spend good, hard earned money for a factory shop manual, one of which I still have. I had to dig into that damn thing, and LEARN what went where.

N' yeh. I made some mistakes.
 
95teetee I tried to send you a private message and found your box is full.
 
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