1956 Cadillac Fuse Question

[gatech1956]

The fuse for my radio blew and kept blowing after I replaced it blew again. After inspecting the plastic casing the the wire that feeds in the bottom of the casing where the spring is just slid out. What holds the wire in? I think the lose connection is why the fuse blew in the first place

[dn010]

I think it is doubtful that a loose connection is what is causing your fuse blowing issue. Fuses will blow when there is a short/too much amperage. If you have a loose connection, the fuse doesn't care whether you have +12VDC or 0 due to a broken wire. I believe the wire runs into the plastic holder, through the spring and is ultimately soldered to a connector that is flat for the fuse base. I changed my fuses to blades in my 57, so if you need a connector I can see if I saved any of them. I suggest digging deeper into this issue, as you'll likely keep blowing the fuses once the wire is fixed.

[gatech1956]

What does the connector look like? The wire just seemed to come out from the bottom and the casing only has the spring inside

[Lexi]

The wire should not pull out from the end (spring side) as there is a flat contact that the fuse sits on that is larger than the entry hole. I agree with Dan that this is a soldered connection. Based on your description the soldered joint has failed. Like Dan, I am uncertain whether a failing contact was blowing your fuses. There may be another problem. You should be able to re-solder the joint unless you have lost the metal contact seat. As the wire has retracted from the fuse holder as you reported, the contact may now be lost. Check your floor to try and locate it. It is a round, shiny flat metal piece the diameter of an old style glass fuse and probably the thickness of a dime or less. Not very big and you could easily miss it. You should see a small lump of solder on one end. The other end has I think a tiny rim that keeps the fuse centered when in normal operation. I think is the same as the other fuse connectors. Remove one of those fuses and push the wire (spring side) up to examine the end connector. That way you will know what to look for. Can post a picture later if you wish. Clay/Lexi

Edit: If you can't locate it and Dan does not have one, I may have a spare connector here.

[fishnjim]

General safety issue;
When a fuse blows or circuit breaker trips, it's best to determine the cause rather than just stick another one in or reset. 
We had strict policies on this because re-energizing faulty circuits can causes fires, etc.   It's a "good practice".

[gatech1956]

If you can check if you have one that would be great. I will keep looking around.

The wire should not pull out from the end (spring side) as there is a flat contact that the fuse sits on that is larger than the entry hole. I agree with Dan that this is a soldered connection. Based on your description the soldered joint has failed. Like Dan, I am uncertain whether a failing contact was blowing your fuses. There may be another problem. You should be able to re-solder the joint unless you have lost the metal contact seat. As the wire has retracted from the fuse holder as you reported, the contact may now be lost. Check your floor to try and locate it. It is a round, shiny flat metal piece the diameter of an old style glass fuse and probably the thickness of a dime or less. Not very big and you could easily miss it. You should see a small lump of solder on one end. The other end has I think a tiny rim that keeps the fuse centered when in normal operation. I think is the same as the other fuse connectors. Remove one of those fuses and push the wire (spring side) up to examine the end connector. That way you will know what to look for. Can post a picture later if you wish. Clay/Lexi

Edit: If you can't locate it and Dan does not have one, I may have a spare connector here.

[dn010]

This is what you're looking for. If you can't find it and want this one, PM me your address and I will send it. If the fuse blew and the wire just came out, it should still be inside the plastic holder.

[Daryl Chesterman]

New fuse holders are available from NAPA—part number 726108 for fuses rated up to 22 amps, or part number 7822075 for AGC fuses with a rating up to 30 amps, or part number 784483 "heavy duty" also with a 30 amp rating.

Daryl Chesterman

[gatech1956]

Good news it has been found. I appreciate everyone's input. As for the radio i am hoping a light bump will he lot clear the vibrator. That's a common cause according to the shop manual

[Lexi]

Fantastic news. I did locate some spares just in case yours did not turn up. Always nice to get these follow ups. Clay/Lexi

[bcroe]

If the fuse never blows when the radio is off, the problem is
likely inside the radio.  In that case I would pull the vibrator
and see if the fuse does not blow.  A welded or shorted vibrator
contact would probably blow a fuse.  Bruce Roe

[gatech1956]

If the fuse never blows when the radio is off, the problem is
likely inside the radio.  In that case I would pull the vibrator
and see if the fuse does not blow.  A welded or shorted vibrator
contact would probably blow a fuse.  Bruce Roe

Thanks Bruce. I suspect it it's the vibrator at this point. Is the vibrator in the radio unit itself? And is there only 1 vibrator? I looked under the dash and saw the speaker has some equipment behind it.

[Lexi]

The 1956 Cadillac radio is a 2 part unit. The tuner (radio dial you see in the dash) and the power amplifier/speaker mounted behind the front passenger dash area. The Vibrator is located there. A tall round tin  can like component that might say Delco Radio Type F.P. on it. May have another name if changed during it's operating life. Clay/Lexi

[bcroe]

The vibrator is at one end of that power chassis mounted by
the speaker.  There is a small metal tube (0Z4) at that end,
power transformer next to them.  Other end has a couple big
glass tubes (12V6), not your problem. 

I would not be surprised if your vibrator was a solid state
replacement.  However, there are other parts that could short
and blow a fuse.  good luck, Bruce Roe

[Saturnin15]

On my 56 sedan deville, the fuse blow when I use the station seeking device.  It goes all the way to the right but when it tries to return to the left, the fuse blow.  Maybe it's just a lubrication problem.

[J. Gomez]

D. Steeves,

I worked on several of these old radios including two of my own '56 and the number one failures with these old radios is the "vibrator".

I have multiple of the 3-prons (for the radio) and 4-prong vibrators (special ones for the Autronic-Eye) and all of them were found to be either totally bad or erratically functioning so I've converted them to electronic style.  I know well these are been reproduce "but" since I'm not sure how they are made I've decided to make my own.

As Clay stated above the '56 has two units the radio aka the "tuner" and the power amp which consists of the high voltage and the audio output.

If yours has the original "Delco" vibrator or an equivalent replacement the chances are it will be defective with age and usage. These tend to have "welded" contacts as Bruce mention or erratically operations due to dirty carbonized contacts, and "yes" a blow fuse is an indication the vibrator maybe the main cause.

But again there are other components that may cause a blow fuse inside the "radio" itself since the main +12V power is switched at the radio and feed to the radio first (low voltage side) and then over to the "power unit" (to energized the vibrator for the high voltage side).
   
One way to isolate these units is to disconnect the wire at the rear of the radio which goes over to the "power unit" this is the switched +12V from the radio. If the fuse blows then the problem is inside the radio if it does not then the issue lies in the "power unit".

Good luck..!

[J. Gomez]

On my 56 sedan deville, the fuse blow when I use the station seeking device.  It goes all the way to the right but when it tries to return to the left, the fuse blow.  Maybe it's just a lubrication problem.

Eric,

That will be the "return solenoid" that may be causing the fuse to blow in your case.

There is a switch (to ground) on the tuner slider which closed to activate the solenoid once the tuner reach pass the 1600Kc dial. When the solenoid pulls in (returning the tuner back to the 550Kc dial) it will wind the mechanical spring (similar to an old mechanical winding clock), this add spring tension for the tuner to "seek" for the next strong station for it to stop until it reaches the end (pass 1600Kc).

Lubrication hmm possible  but again there could be other factors as there are other mechanical and electrical components around the auto-seek features for these radios.

[V63]

D. Steeves,

I worked on several of these old radios including two of my own '56 and the number one failures with these old radios is the "vibrator".

I have multiple of the 3-prons (for the radio) and 4-prong vibrators (special ones for the Autronic-Eye) and all of them were found to be either totally bad or erratically functioning so I've converted them to electronic style.  I know well these are been reproduce "but" since I'm not sure how they are made I've decided to make my own.

As Clay stated above the '56 has two units the radio aka the "tuner" and the power amp which consists of the high voltage and the audio output.

If yours has the original "Delco" vibrator or an equivalent replacement the chances are it will be defective with age and usage. These tend to have "welded" contacts as Bruce mention or erratically operations due to dirty carbonized contacts, and "yes" a blow fuse is an indication the vibrator maybe the main cause.

But again there are other components that may cause a blow fuse inside the "radio" itself since the main +12V power is switched at the radio and feed to the radio first (low voltage side) and then over to the "power unit" (to energized the vibrator for the high voltage side).
   
One way to isolate these units is to disconnect the wire at the rear of the radio which goes over to the "power unit" this is the switched +12V from the radio. If the fuse blows then the problem is inside the radio if it does not then the issue lies in the "power unit".

Good luck..!

Once the poor connection at the fuse holder has been addressed and the OEM style Vibrator problem is diagnosed...

I have had success 'skinning' the metal capsule of the OEM style vibrator and cleaning /servicing them.

[dn010]

Make sure it is the FAT metal canister looking piece you try to remove; if it is the right item, you will be able to rock it back and forth in its connector if you try moving it gently.

I post this warning because there is a multi-section, vertical mount capacitor nearby that is also in a metal canister looking item (if it has not been replaced) - This will be THIN compared to the vibrator and this will be solid if you try to move it gently but you can damage things if you try to force this one to the side trying to get it out.

[J. Gomez]

I have had success 'skinning' the metal capsule of the OEM style vibrator and cleaning /servicing them.

Agree, there are several methods to rejuvenate these old mechanical vibrators some technics are very dangerous while others are straightforward as you mention by burnish the contact.

However these can last for years or just month/days before failing again depending on usage, these contacts do generate a lot of arching while in operation so is just a matter of time.