armored ignition wire

[mchev150]

working on getting the Wayfarer running and installing the pieces that came in boxes...

There is an armor covered wire coming thru the fire wall that is flopping around. The manual indicates that it is supposed to originate at the ignition switch. Any insight on how/if it attaches to the switch ?? And does armor covered section of the wire supposed to be on the interior side of the firewall?? Lastly why is the wire armor covered in the first place???

Thank

Mike

[greg g]

Early anti theft device, makr it harder to cut/pull the cable and jump start the car. I don;t have any experience with the actual switch set up but I think it was swedged into the switch mechanism. It is possible you switch has been changed to a later non armored style and re wired.

You might want to run a search as it ha been mentioned a few times in the past. If your ign switch has exposed terminals, just hook a new wire from the ignition side to the negative post on the coil and it should get you going till and if you redo the armored deal.

[blueskies]

The armored cable was a theft prevetion device, meant to make hot wiring the car more difficult. It runs from the back of the ignition switch to the firewall grommet. The wire inside runs from there into the engine compartment without the armored part.

I removed the armored cable from my factory switch, as seen in the attached pic. I opened up the case of the switch, and soldered in a new wire to replace the old wire that was falling apart. The switch was a mother to get open, but it was worth the trouble.

Pete

[mchev150]

thanks guys, it would never have occurred to me that this was to prevent theft

[Young Ed]

The older cars and trucks have an armored cable that clamps right onto the coil. The coil goes in a hole through the firewall. So that wire is tucked under the dash and really hard to get at

[Norm's Coupe]

I can't really say if my ignition switch was replaced or not over the years. However, I've never had that shielded cable for the ignition wire under the dash.

[Don Coatney]

Believe this was a pre war thing.

[Young Ed]

My p15 doesn't have it either but the 51-52s have it. My truck has the other style I mentioned above

[Young Ed]

OK here is the truck version. The igniton to coil wire is completely contained.

And here is the p23 version. Look up and towards the drivers side from the oil canister. Its in a grommet.

[TodFitch]

On the early 1930s cars the ignition switch/armored cable/coil are all in one assembly that is a bear to take apart and repair/replace. The coil mounts through the firewall with only two connections under the hood: A low tension wire to be grounded through the points and the high tension wire to the distributor cap center.

The engine compartment side of this can be seen in this photo. Notice the coil mounted on the top center of the firewall with only two wires attached. The third wire is the armored wire under the dash

The ignition switch itself can be described as a three pole single throw switch. When it is in the off position all contacts are isolated from one another. When in the on position all contacts are joined. One contact is for the fuel gauge, one for power and the third wired through the attached armored cable provides power for the coil.

So you can't just jump power to the coil to "hot wire" the car as the power feed is entirely armored. And putting power on the gas gauge contact won't power the coil either if the switch is off.

I am not sure when they stopped using variations in this scheme but it seems to have been pretty standard on all Chrysler products and some other manufacturers as well.

[Bmartin]

I'm going to piggyback onto this thead as its a similar question.  I have a 1940 plymouth and the coil is mounted on the firewall,the same as Todd's above.  I've been having intermittent shorting issues.  Tonight I narrow it down to the armored cable under the dash.  I even saw a little puff of smoke from the inside firewall at the back of the coil when moving it around.  The wire inside is pretty mangled. 

 

 

Here is my question.  When I perform a continuity test between the center wire and the armor of the cable, I get continuity.  I would think this would inidcate a dead short, but my ammeter is only reading a very slight draw with the ignition in the on position.  When I get the shorted condition, the ammeter goes full negative.  Any ideas on how I can read this short, but not have a full negative current at the meter?  Is this something to do with where the points are in the ignition?  All help is appreciated. 

 

Funny thing is that after the little puff, I can no longer recreate the dead short by moving the cable around. 

[JDaniel64]

Does your ammeter/voltmeter have a setting for testing resistance? I would check that against the shielding and the wire and see if there is any reading.

[Mark Haymond]

Like blueskies said. My 1950 Plymouth has the armored cable too which runs from the back of the ignition switch and goes through the firewall. The armored part sticks out into the engine compartment about an inch. It makes it difficult to jump power to the coil from inside the car. Like blueskies I took the tedious route and opened up the ignition switch. A dremel tool came in handy. I soldered in a brand new wire and re used the armored cable. It has worked OK the last ten years.

[_shel_ny]

I believe the armored cable is overkill.( EDIT:Reread of the thread, I see it was theft deterrent) They were not used on 46-48 cars. They used them again in 49- maybe 52 on some. Those were like the one  Mark has with the armor extending out into the engine bay, then just the wire continuing to the separate coil. I would carefully cut the armor cable back near the switch, and eliminate the bad wiring. You can do that with a dremel. Go slow be careful. Start out away from the switch, and cut again if you slip and damage the wire. A light nick could be covered with some  shrink tubing. A recurring dead short will do nothing good for your car.

Edited April 24, 2014 by shel_ny

[Dave72dt]

My first thought was the armored cable was acting as a ground. That little puff of smoke may have been some arcing where the cable attaches to the car. If the cable was not touching any metal, would you still have continuity?

[desoto1939]

working on getting the Wayfarer running and installing the pieces that came in boxes...

There is an armor covered wire coming thru the fire wall that is flopping around. The manual indicates that it is supposed to originate at the ignition switch. Any insight on how/if it attaches to the switch ?? And does armor covered section of the wire supposed to be on the interior side of the firewall?? Lastly why is the wire armor covered in the first place???

Thank

Mike

MIke The armor cabled wire runs from the iginition switch to the back of the firewal.  There should also be a metal cover that has  four tabs on it. the Coil then was monteed thru the firewall and bolted to the inside of the engine compartment.  The wire then is screwed into the back of the coil and thenthe metal cover is snapped into place on the back of the coil. 

 

Not sure if you knew this information.

 

Rich HArtung

Desoto1939@aol.com

Edited April 24, 2014 by desoto1939

[_shel_ny]

MIke The armor cabled wire runs from the iginition switch to the back of the firewal.  There should also be a metal cover that has  four tabs on it. the Coil then was monteed thru the firewall and bolted to the inside of the engine compartment.  The wire then is screwed into the back of the coil and thenthe metal cover is snapped into place on the back of the coil. 

 

Not sure if you knew this information.

 

Rich HArtung

Desoto1939@aol.com

To clarify a bit, Mike (Post from 6 years ago) does not have the coil attached to his armored cable. (and we do not know how he resolved his problem) Bmartin has the "coil attached" set up, and provided a great pic of the wire, and tabs.  Rich, your input is always appreciated, just wanted to clarify a bit

Edited April 24, 2014 by shel_ny

[desoto1939]

Shel_ny:  When i posted my reply the pictures of the coil and that post was not showing for me.  Is is strange that at a certain point the stoped the armored able and then went back to it. Could it have been when they moved the coil from not being attached to the firewall and then had it mounted onto the sparkplug wire loom seperator?  I do know that when the coil was in the firewall there was a thought that the extra length of the wire to the dizzy was giving them some issues.

 

Rich

[Bmartin]

I measured the actual resistance tonight.  Its about 2.4 ohms from the wire to the armor.  Its pretty much zero from the armor to chassis.  Wonder if the coil has a resistance of approximately 2.4 ohms?

Edited April 25, 2014 by Bmartin

[JDaniel64]

2.4 ohms between the wire and the armor tells me that there is definitely a short in there, the resistance is too low not to be... 

[TodFitch]

I measured the actual resistance tonight.  Its about 2.4 ohms from the wire to the armor.  Its pretty much zero from the armor to chassis.  Wonder if the coil has a resistance of approximately 2.4 ohms?

 

2.4 ohms between the wire and the armor tells me that there is definitely a short in there, the resistance is too low not to be... 

 

Is the coil in the car with the primary wire attached to the coil? At least on my car the engine usually stops at a position where the points are closed so I'd be measuring the resistance through the primary windings of the coil which might be close to 2 1/2 ohms. If the primary wire is off, then the resistance should be infinite.

[JDaniel64]

Is the coil in the car with the primary wire attached to the coil? At least on my car the engine usually stops at a position where the points are closed so I'd be measuring the resistance through the primary windings of the coil which might be close to 2 1/2 ohms. If the primary wire is off, then the resistance should be infinite.

 

True true, i did not think of that, the resistance would be low through the primary of the coil, if the points were closed it would complete the circuit to ground and yield a low reading at the armored cable. Disconnecting the wire at the coil or making sure the points are open would be a good step in troubleshooting. Checking the resistance across the actual coil would help and isolating the wire and checking it against the armored cable would yield better results. My thinking is steel has a higher resistance per length than copper does, so a value for a short with copper-to-steel conduit, to me, is in the 1-5 ohm range, and a short from copper-to copper is <1 ohm, at least that's what my mistakes with electricity have taught me 

Edited April 25, 2014 by JDaniel64