What is this?

[Labradorian]

see white arrow in pic., looks like a condenser. what is it? Voltage limiter?

these are guage clusters out of late 66 fury's
the gauge cluster on the left if out of my 66 Monaco(canadian version) it never had that cylinder thing mounted to it.
the gauge cluster on the right is a spare that my father(original owner of the car) picked up years ago. not sure what year car it came out of.

the only difference between them is the cylinder thing mounted as shown, and is connected to the +12V input terminal of the fuel gauge.

thanks
Glen

 

[twostick]

Looks like a condenser but for what purpose I have no idea. Maybe to protect the gauges from a voltage spike?

Do you have an FSM or a parts manual? That might shed some light on the subject.

Kevin

 

[Labradorian]

Looks like a condenser but for what purpose I have no idea. Maybe to protect the gauges from a voltage spike?

Do you have an FSM or a parts manual? That might shed some light on the subject.

Kevin

Hi Kevin

I do have a full service manual for 66 Monaco and Fury and parts manual for all models of Mopar in 66. It does not show this cylinder thing in the parts catalog diagram of the instrument cluster for the 66 fury and no mention of it in the manual. perhaps it was added in another model year.

thanks

Glen

 

[67Monaco]

Standard on the 67's.

 

[Labradorian]

Standard on the 67's.

Thanks Is it a Condenser?

 

[polara71]

voltage limiter !

 

[Big_John]

It's a capacitor (condenser). It's there to cut down noise to the AM radio.

 

[Labradorian]

voltage limiter !

It's a capacitor (condenser). It's there to cut down noise to the AM radio.

thanks Just to clarify that A voltage Limiter and capacitor(condensor) are 2 different things. Im confused as to why they would install a capacitor on the back of the gauge cluster and not directly to the circuit feeding the radio.

thanks guys

 

[polara71]

I was always told they are a voltage limiter but I have no reason to know what the hell they are

 

[Big_John]

Trust me, it's a capacitor and I'm not guessing.

You connect a capacitor to things that are going to interfere with the radio, not to the radio.

All sorts of things generate radio waves (RF). Ignition, alternator, motors and even things like wheel bearings. That RF may interfere with radio reception. Without going into theory about how it works, the capacitor filters out the RF interference.

You'll find that 12+ terminal on the gas gauge was the convenient place for the capacitor to hook to. It suppresses any RF interference from things like the heater fan.

Here's an older book with a decent description of how this all works. It's English, so it has words like "bonnet" for hood and "earth" for ground, but you can get the idea.

http://www.google.com/url?sa=t&rct=...=Fd4g4sZsH9DZiqb57vMlwg&bvm=bv.89217033,d.eXY

 

[Labradorian]

I was always told they are a voltage limiter but I have no reason to know what the hell they are

The voltage Limiter on my monaco and Fury is inside the fuel gauge and limits the voltage from 12V to 5V for the gauges. I'm not trying to be an ***, The only reason I'm clarifying the difference is because I'm having trouble with my gauges and knowing what exactly this is and what it does is important. important because I removed the fuel gauge from the cluster that has this tube and put it in the cluster without the tube. i wanted to know if it is a voltage limiter, I guess i can test the voltage when it is connected to confirm.

thanks

 

[Big_John]

IIRC, the voltage limiter is internal to the gauges in these early/mid sixties cars.

 

[Labradorian]

Trust me, it's a capacitor and I'm not guessing.

You connect a capacitor to things that are going to interfere with the radio, not to the radio.

All sorts of things generate radio waves (RF). Ignition, alternator, motors and even things like wheel bearings. That RF may interfere with radio reception. Without going into theory about how it works, the capacitor filters out the RF interference.

You'll find that 12+ terminal on the gas gauge was the convenient place for the capacitor to hook to. It suppresses any RF interference from things like the heater fan.

Here's an older book with a decent description of how this all works. It's English, so it has words like "bonnet" for hood and "earth" for ground, but you can get the idea.

http://www.google.com/url?sa=t&rct=...=Fd4g4sZsH9DZiqb57vMlwg&bvm=bv.89217033,d.eXY

Thanks Big John

As a electrical designer I completely understand what you are saying and now that I know its a capacitor. I kind of guessed it was put there for convenience and yes it makes sense now that it is placed closer to the source and not directly to the radio.

Thanks for the clarification

Cheers guys appreciate the help.

 

[Labradorian]

IIRC, the voltage limiter is internal to the gauges in these early/mid sixties cars.

thanks again, Big john. I can only speak for the 66 model year. this applies for the fury, but based on the 66 Plymouth full shop manual for other Plymouth models of that year, the voltage limiter is external to the gauges. the same applies to the 66 dodge monaco.(non canadian version)

 

[mcmlvii]

The voltage limiter in my '66 Fury is inside the fuel gauge so Labradorian's would most likely be in the fuel gauge too, his car having a Fury dash. My limiter is cooked so I use a homemade external 5v power supply. Not sure if this was mentioned previously, but the condenser is to filter out the noise from the stock voltage limiter, which uses a set of quickly opening/closing points to limit the voltage to the gauges. A bimetallic strip has some resistance wire wrapped around it and when 12 volts runs through the wire, it heats up, causing the bimetallic strip to bend and open the points, thus breaking the circuit. The wire and strip cool and the points close, allowing juice to again flow. It does this process over and over, and the outcome is a reduced voltage to the gauges. It's kind of a crude pulse width modulated regulator from what I understand.

 

[mcmlvii]

One other thing, if the stock voltage limiter points stick closed, it will allow the full 12 volts to run through the gauges, and in the process most likely fry a gauge or two. That will ruin your day... Yet one more reason to go with a solid state voltage regulator.

 

[Labradorian]

One other thing, if the stock voltage limiter points stick closed, it will allow the full 12 volts to run through the gauges, and in the process most likely frying a gauge or two. That will ruin your day... Yet one more reason to go with a solid state voltage regulator.

yes that's is what I'm getting , the full 12v through On all 3 fuel gauges I have. I'll test the gauges tommorrow to see if they are fried with my ohm meter. Or I ll check to see if my cell phone charger is 5v. I have 3 sets of gauge clusters so hopefully I can get at least one good temp and fuel gauge out of the mix.

Cheers
glen

 

[BillGrissom]

The "voltage limiter" should really be termed "voltage regulator". It will always have 3 terminals. It is inside the fuel gage in my 64 & 65 A-bodies and I think in my 65 Newport. It changed to a rectangular plug-in box on the back of the cluster by 1969. Cars w/ the tachometer (rally) dash still had it inside the fuel gage until ~1973. The 2 terminal device shown is surely a capacitor, also termed "condenser" and such.

For those wanting to upgrade, there is an inexpensive (~$25) electronic "voltage limiter" on ebay (or RTE for more $$). Search that term. You will need to open your fuel gage to disable the limiter, unless it already killed itself. It also allows you to tweak the output voltage so either your fuel gage or temp gage reads exactly right. Each gage also has 2 screwdriver adjustments (for zero and range), but those bend brackets and such so were intended only for the manufacturer to adjust once. I fried the fuel gage in my Newport long ago when trying to trouble-shoot and I was more clueless. I installed an under-dash gage. I need to fix it someday. Didn't affect my temp gage, since my car just has the cold/hot lamps.