67 Barracuda gauge info needed

[Bucky Jones]

Need advice/availability of instrument panel gauges/repair. Fuel gauge works, Temp, oil pressure, and ammeter not hooked up but questionable. Vacuum gauge was working but sticks now???? Rather have a tach or good vacuum gauge. Car came heat and radio delete so the instrument panel is unique. Any help muchly appreciated..

 

[coloradohill]

I would think that @RAT ROD AL could help you.

 

[Super-Cuda]

Need advice/availability of instrument panel gauges/repair. Fuel gauge works, Temp, oil pressure, and ammeter not hooked up but questionable. Vacuum gauge was working but sticks now???? Rather have a tach or good vacuum gauge. Car came heat and radio delete so the instrument panel is unique. Any help muchly appreciated..

Box up and send the gauges to these guys.

Fantastic service, reasonable prices and very well shipped.

Welcome — Mr Heaterbox and Interior Restoration Services

 

[RAT ROD AL]

Sorry but I don't have any 67ish gauges at the moment.

 

[Mattax]

Need advice/availability of instrument panel gauges/repair. Fuel gauge works, Temp, oil pressure, and ammeter not hooked up but questionable. Vacuum gauge was working but sticks now???? Rather have a tach or good vacuum gauge. Car came heat and radio delete so the instrument panel is unique. Any help muchly appreciated..

Advice
A: Change the subject of the thread from 'needed' to 'advice needed' befoer a moderator locks the thread or moves it to the Wanted to Buy forum.

B. Good news is you can do some testing of the instrument panel gages with some basic equipment.
1. Do a resistance check on all of them.
For the thermal gages - oil pressure, coolant temperature, fuel. There should be around 20 ohms resistance. If its in spec, great, time to see if they work. For the ammeter, there should be zero resistance. Touch the probes together first - that will be the zero. Then check the ammeter. If the studs are tight and no measurable resistance, then its probably OK.
2. For the thermal gages. These can be driven with a couple of C or D cell batteries in series. This will reveal if they work. Or even better yet if they are on the bench, get yourself some 11 and 22 ohm resistors or a variable resistor (potentiometer) and a 12 - 14 volt power supply (a car battery will work fine). Power the Instrument Voltage regulator in the fuel gage and use jumpers to hook up the gages to the resistors.
This would be the most thorough test. If the IVR isn't working, then get that fixed or replaced.

 

[Mattax]

Here's a post with links to Chrysler Service information and several threads about testing the thermal electric gages.

Rallye Instrument cluster voltage limiter - 68 Barracuda

I recently did reworking of the gauge cluster to replace lights in my 1968 Barracuda, and replace both of the circuit boards with ones from Classic Industries. Everything worked fine for a while after, until the temperature, oil pressure, and fuel gauges started going strait to max travel with...

www.forabodiesonly.com

The ammeter is different in two ways.
First, its not connected to the other gages on the instrument panel.
Second, it is connected directly into the battery line.
The electrons moving though the metal plate in the ammeter make the needle move.
How do they do that?
The plate goes around the pivot of the needle. The electrons moving past create a small electro-magnetic field. The magnetic field deflects the needle.

Side notes:
1. Just because resistance showed zero with a multi-meter doesn't guarentee zero resistance in operation. That's true for all connections in the electrical system. The meter just shows there is no major issue. When current flow is high, resistance smaller than the meter can measure can cause loss in voltage. For example, if the alternator is producing power at 14 Volts, and you measure 13 Volts at the battery, or at the headlights, or at the voltage regulator input, that was caused by resistance somewhere between the alternator and the location(s) of lower voltage.

2. The ammeter only shows current flowing in or out of the battery. If it shows the discharge when the engine is running, then something is wrong with the alternator circuit. If it shows charge, then the battery is charging. If it shows zero with the engine running, then the battery is charged.

3. Everything connected to the ammeter is connected to the battery positive. All of those wires and connectors are hot as long as the battery is hooked up. Be careful when working with them! Best to disconnect the battery.

 

[toolmanmike]

Need advice/availability of instrument panel gauges/repair. Fuel gauge works, Temp, oil pressure, and ammeter not hooked up but questionable. Vacuum gauge was working but sticks now???? Rather have a tach or good vacuum gauge. Car came heat and radio delete so the instrument panel is unique. Any help muchly appreciated..

Advice
A: Change the subject of the thread from 'needed' to 'advice needed' befoer a moderator locks the thread or moves it to the Wanted to Buy forum.

B. Good news is you can do some testing of the instrument panel gages with some basic equipment.
1. Do a resistance check on all of them.
For the thermal gages - oil pressure, coolant temperature, fuel. There should be resistance. If its in spec, great, time to see if they work. For the ammeter, there should be zero resistance. Touch the probes together first - that will be the zero. Then check the ammeter. If the studs are tight and no measurable resistance, then its probably OK.
2. For the thermal gages. These can be driven with a couple of C or D cell batteries in series. This will reveal if they work. Or even better yet if they are on the bench, get yourself some resistors or a variable resistor (potentiometer) and a 12 - 14 volt power supply (a car battery will work fine). Power the Instrument Voltage regulator in the fuel gage and use jumpers to hook up the gages to the resistors.
This would be the most thorough test. If the IVR isn't working, then get that fixed or replaced.

Thanks Matt. Title changed to info needed. Once Bucky figures out what to do and what he needs, he can open a Parts wanted ad. This isn't one.

 

[CFD244]

@4spdragtop had some '67 dash components. Maybe he can help with some info.

 

[Bucky Jones]

Thanx ya'll. Not a parts wanted yet. I'm an electronics guy and really want to fix my original stuff. The vacuum gauge is sticky, and the fuel gage works (IVR ok ??). I have the entire cluster out.

 

[Mattax]

Cool. then you can test most everything.
Here's one more thread: This one has the resistances needed and where the needle should move.

Homemade gauge test tool, C-3826

I finally dug through the junk box, went down to Radio Shack, and built myself a copy of the Mopar C-3826 guage test tool. It's a little crude, but hey, I'm not going to "show" it. According to what I can find, the three test resistances for senders (in the C-3826 tool) are L...

www.forabodiesonly.com

As mentioned in that thread, aftermarket sending units often don't match the original 67 sending unit resistances. Oil pressure and fuel senders being the most common offenders people complain about here. The fuel senders can be rebuilt - so that's at least one solution if you have the original.

 

[Bucky Jones]

Thanx for your help. Much! Fuel gauge works. Will be testing others. I assume the IVR is in the fuel gauge...????

 

[Mattax]

Yes.

I is system power input. A is the IVR output, S connects to the fuel sender

So if you are supplying power at reduced voltage (such as a 3 Volts from a dry cell)

Fuel gauge is tested same way but at posts A and S. If the gauge is on a workbench, the limiter isn't chassis grounded, back feed voltage into that limiter cannot go anywhere or have any effect at all.

If you have the whole panel on the bench, then the I terminal can be supplied at 12-14 V if the panel is grounded. There's a ground wire to help insure a good ground to the instrument panel - you can clip onto that.