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problem wth the resistance wire to the coil

Started by hypocad, February 04, 2016, 03:29:39 AM

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hypocad

hello i ve got a problem with the resistance wire fro the starter to the coil; the wire iis very hot when the motor s runing .i switch it with a normal wire and the coil turns very hot and the breaker is dead.so i buy a new electronic ignition may i put a ballast resistor on the normal wire before the coil or something else  thank you sorry for my english for a caddy coupe de ville 1960

Bobby B

What type of car, year, etc.? ???  Need more info.
                                 Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

TJ Hopland

More details will help.   

In general most of the conversions don't use a resistor so replacing it with standard wire would be correct.

Many breaker / points systems have 2 feed wires to the coil.    One wire is live when the key is in the on position, this is the wire that has the resistor in it.    The other wire is only live during starting.   How this was done varies depending on the year and model.   Sometimes this was an extra terminal on the key switch other times it was an extra terminal on the starter solenoid.   That wire and extra terminal will have power on it when the key is on because its connected to the other wire through the resistor.    What makes those terminals special is they are only connected when the starter is turning. 

Where things get messed up is connecting other things to those wires like say an electric choke or alternator.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

lou-q

I replaced that resistor wire with a regular wire then one day I left the ignition switch on after I parked it and the dash caught on fire after a couple of hours. I'm in the process of a complete restoration due to that fire.
Lou
Lou Quirch    CLC#26694
39-6127 coupe
67 DeVille convertible Venetian Blue
67 DeVille convertible Doeskin SOLD
67 Corvette Marina Blue Roadster
2015 Mustang GT 50th anniversary Black Convert
2020 Shelby GT500 Magnetic Metallic
67 DeVille convertible Donor car for parts
3 F250 Ford P/Us

Classic

Resistance wire typically has a steel, not copper, conductor.  Steel has a higher resistance per foot than copper.  The length of resistor wire is critical in order to provide the correct resistance.  You will need to determine the specific gauge and length of resistance wire you need for your application.  A hot wire indicates too much current which mean too little resistance.
Gene Menne
CLC #474

TJ Hopland

Quote from: lou-q on February 04, 2016, 11:54:51 AM
I replaced that resistor wire with a regular wire then one day I left the ignition switch on after I parked it and the dash caught on fire after a couple of hours. I'm in the process of a complete restoration due to that fire.
Lou

In your case was this using one of the electronic ignition conversion kit that said to eliminate the resistor wire?   Or was it still a stock system?   If it was a stock system by the time the dash wire melted I bet the coil was well on its way to being a melted blob too.

For a conventional points system the resistance (wire or resistor) was there as a current limiting device.   This function comes in to play both running and not running.    Not running key on is an especially big issue.  If the engine happens to stop with the points closed the resistor is the only thing you have to possibly 'save' the system.  I believe the Mopar electronic ignition system still used a resistor because it was still possible for the engine to stop in the 'on' position so if the key was on you could have had the same issue.  The GM HEI used a micro processor in the module so it was 'smart' enough to know that the engine had stopped so it would not leave the power on to the coil so they didn't use a resistor with that system.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

fishnjim

Running current through a resister produces heat.   The ballast resister lowers the voltage almost in half so it probably might get a little hot.  It's open and insulated for that reason.   If you change the wire or it's length you change the resistance and hence the voltage.   They make replacements.   

lou-q

Thanks,
Who makes replacements for the resistor wire?
I tried to find some wire and all I can find is some wire from The Brillman Co that they call resistor wire. If I remember correctly their wire is stranded. The original was single conductor steel and something like cloth insulation. I would love to find some of the right wire since the harness I'm using from the donor car doesn't have the right one either.
Thanks,
Lou
Lou Quirch    CLC#26694
39-6127 coupe
67 DeVille convertible Venetian Blue
67 DeVille convertible Doeskin SOLD
67 Corvette Marina Blue Roadster
2015 Mustang GT 50th anniversary Black Convert
2020 Shelby GT500 Magnetic Metallic
67 DeVille convertible Donor car for parts
3 F250 Ford P/Us

MY 59

I would hazard a guess that almost any car from that era, certainly from GM would have the correct wire if you can source one.
I had a quick look for a source for new ones and yeah it didnt look like much out there?
David Bone :)

1959 Cadillac Sedan Deville
1967 (aussie) ZA ford Fairlane

TJ Hopland

I don't know how many other applications there were for resistance wire like what was used in some cars.   I would suspect most searches for resistance wire you would turn up something made of nichrome which is used in a similar fashion for large power supplies and for heating elements.

Have you tried searching some of the popular to restore GM cars?  Maybe they make reproductions for Firebirds or Corvettes? 

Are you trying to be original or just get something that works?   If you just want something that works there were a lot of applications that used a ceramic resistor.   They are still readily available and are cheap.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason