What's This Thing?

[dagizmoguy]

Well ...this went up in smoke under the dash of my 47 Plodge and now the fuel gauge doesn't register.

Would someone tell me please what this is called and where to get one?

Many thanks!

David

[Plymouthy Adams]

I think this is a radio suppressor for the fuel gauge so to prevent the audible click from the switch opening and closing which is part of the fuel voltage regulator built into the guage

[BobT-47P15]

Was it actually part of the fuel gauge, or in the line behind it?  Looks like a resistor type item.  Tim may be

correct in his assessment of what it is........but don't recall seeing one like it on my P15.  Is your car still

6 volt or changed to 12V?

[dagizmoguy]

It was attached to the back of the gauge

and the car's 12 volt......

I'm mystified........

thanks,

David

[T120]

 

I believe Plymouthy is correct.It was used as a noise suppressor and is not required for your gas gauge to operate as long as there isn't another problem with your wiring.Check the wire from your ignition to the gas gauge,it may need replacing as excessive current was passed through that wire.Toss the part in the picture you posted in the garbage...

 

 

[dagizmoguy]

OK!

Many thanks, I'll check all the wiring....

Sure glad I don't need it cause finding another one would be a bi-t-ch for sure.

Thank you!

David

[T120]

David,

         Noticed your car is converted to 12 volts.Was this done by you or the previous owner?Just wondering what changes if any were made in the stock wiring to the fuel gauge.In any case I would suggest adding an in-line fuse to the gauge.Some have added a voltage dropping device to their dash gauges in converting to 12 volts,others have said they were not required.Maybe someone could chime in with their experience?...   

Edited April 5, 2013 by Ralph D25cpe

[Dodgeb4ya]

All the 1946-8 Chryslers with radio's have that item installed as it was standard on them. Just a source that should have one.

Bob

[T120]

All the 1946-8 Chryslers with radio's have that item installed as it was standard on them. Just a source that should have one.

Bob

Hmmm...Don't see it on this diagram...I guess as you mentioned only those with radios.

Edited April 5, 2013 by Ralph D25cpe

[Dodgeb4ya]

I take it back not all Chryslers have this supressor. Most all of the 46-8 chryslers I have worked on have this item. Two of my cars have them. I have one around somewhere but I cannot find it. It came off a parts dash last summer.

A picture of the Chrysler supressor installed on one of my Chryslers and a parts dash. No wiring diagrams ever show it.

Bob

 

 

Edited April 6, 2013 by Dodgeb4ya

[Oldguy48]

I wouldn't throw yours away.  It looks to me like that's a capacitor (that tubular component) mounted on a phenolic board.  Maybe the capacitor shorted.  You might be able to clean up the residue, and replace the capacitor.  Does the capacitor have any markings on it? (Like 0.1 mfd or something similar).  I'm only guessing here, as I've never seen one of those suppressor modules before, but it might be repairable, and capacitors are a common electronics component.

 

Wayne

[dagizmoguy]

The conversion to 12 volt was done by a previous owner. The capacitor just says "SPRAGUE MADE IN USA" with a patent number that was issued around 1935 (1,900,093). I son't see any other markings anywhere.

[Oldguy48]

Sprague is/was a major manufacturer of capacitors, so that makes it highly probable that's what that component is, and capacitors are commonly used for just that application.  If it were mine, and if the module wasn't too badly damaged, I'd find a replacement capacitor of 0.1, or 0.2 mfd (microfarad), and replace the defective one, clean up the charred areas of the module, and try it out.  You probably won't find new capacitors that have that same appearance though.  The old style from that era was a wax impregnated tubular capacitor.  Newer ones are much smaller, but serve exactly the same purpose.  I would try to find one with at least a 25 volt rating (or higher). Radio Shack may stock them.  If you look at the defective one, there's probably a black band at one end, indicating polarity.  A replacement capacitor should have a similar marking.  Just connect it in the same way.

 

Wayne

[T120]

Needless to say wiring going up in smoke can cause serious damage and is not something to be taken lightly. There is a lot of short circuit current available from a car's battery and that is why I suggested it may be wise to use an in-line fuse. Original wiring insulation generally becomes brittle with age and exposes bare wire which may short to ground...Not sure how familiar you are with wiring and judging it's seviceability.
If the gas gauge was working correctly before the smoke,it may be as Wayne suggested and the problem may have been a  shorted capacitor.That said,the part in your picture including the capacitor is not required for the fuel gauge to operate...imho

[Plymouthy Adams]

some of these old caps were aluminum and an insulator wrapped around each other..over time they break down and the results is either a smoke job or if a sealed cap can be a big bang...with foil blown everywhere. Old caps are notorious for going south. Odds are if you are running a modern radio in that pig the cap is not needed as they pretty much have a good input filter...

[dagizmoguy]

Oh Man! Did I ever come to the right place!

Thanks for all this information!

The module is really fried, there's hair like burnt wires all hanging out of it like a head full of split ends.

I'm going to check all the wiring for safety, install the in line fuse and if the capacitor isn't necessary for the gas gauge to work I think I'll just leave it out.

Thank you guys, you're much appreciated!

Best wishes to you all,

David