BALLAST RESISTOR????

[80spit]

Do all 1500's have a ballast resistor, I cannot find one on my 1980.

There is a traditional type resistor next to the coil, connected to the positive pole but it looks like a noise radio supressor for the coil.

I sill have the points and condenser Lucas dist.

thanks

 

[SBooth]

I had a 1980 1500 a few yrs. ago and I recall that Triumph used a resistance wire to the coil instead of a seperate ballast resistor. You could check w/ a volt/Ohm meter.
Steve

 

[guzzul]

Do all 1500's have a ballast resistor, I cannot find one on my 1980

Yes, unless it has been removed. You should have a piece of ballast wire coming off the start solenoid. It's a pink/white stripe wire. If a PO has installed a non-electronic dizzy, its possible this wire has been removed or bypassed, although the function of the ballast wire is to reduce voltage at the coil, not the dizzy.

There is a traditional type resistor next to the coil, connected to the positive pole but it looks like a noise radio supressor for the coil.

That blue 'can' at the coil is actually a capacitor (condensor). And it is for radio noise suppression.

 

[80spit]

So if I have 12 volts on both sides of the coil I need to install a resistor.

Should I put it between the coil and the dizzy, or before the coil.

This is probally why I cooked the points.

 

[YankeeTR]

The ballast resistor should reduce the voltage to the points to prolong their life.

The coil should always receive a full 12 volts and, if it is wired like most other systems, it should have a bypass wire coming from the starter switch or starter solenoid. When you hit the 'start' position the points get a full 12 volts for easier starting. When you release the keyswitch that wire goes dead which means the wire with the resistor takes over and the points only get 6 to 7 volts.

If you wire the coil with the resistor BEFORE the coil you will have hard starting and spark plug fouling because of low voltage to the spark plugs.

 

[TR3driver]

If you have 12v on both sides of the coil, then the points are open and you can't tell if there is a ballast or not. Turn the engine until the points close, and check again.

Standard practice is to have the resistor between the switch and the coil (so it can be shorted out during starting); but it will actually work the same between the coil and the points (except for starting, obviously).

The other question, of course, is which coil you have. Some coils (eg early Spitfire) do not require a ballast resistor. Easiest way to check is with an ohmmeter or DMM : measure the resistance across the two small terminals. If it's 3-4 ohms, then the coil does not require a ballast. 1-2 ohms means it does.

 

[YankeeTR]

"Standard practice is to have the resistor between the switch and the coil"

You are right...I had my head up my butt...

 

[80spit]

I am still stumped, I have 12 plus volts at the coil, no spark still at the HT wire to the dizzy.

Does the wire to the points come from the + or - side of the coil?

I tried a second coil same result with points open I get full voltage, closed I get about 6 Volts to the dizzy.

Is there something unique to the 1500.

Thanks for the help.

 

[TR3driver]

The coil should be wired with power from the switch (through the ballast) to the "+" terminal; and the "-" terminal linked only to the points & condensor inside the dizzy. (On a non-US spec 80 Spit. I believe US-spec had an electronic module instead of points.)

With the points closed, 6V on the "+" would be normal (indicating the ballast wire is working), but the "-" terminal should be at zero. 6v on the wire to the dizzy is wrong, indicating probably a broken wire or bad connection either at or inside the dizzy.

If you are seeing 6v on the wire to the dizzy, take the cap off and trace down where the voltage drop is. One (rare)possiblity is the wire that ground the point plate, which sometimes breaks internally even though the insulation looks OK. The same thing happens to the wire from the side of the dizzy to the points.

When you check for spark, do you have the high tension wire disconnected from the dizzy ? There has been a rash of bad rotors in recent years, and one of the symptoms is that they short the spark to ground.

 

[AltaKnight]

Normal -ve ground cars have the wire between the points and the coil attached to the - side of the coil. Thus when the points are closed the current is flowing through the coil to ground and building the field; as the points open the current flow stops and the field collapses firing a spark on the HT wire.

The -ve side of the coil should ground through the points when they're closed and should not have a ground path at all when they are open. A lot of problems are caused by incorrect assy of the points (all those little plastic washers and bits) which will lead to a false ground.

 

[80spit]

I am getting voltage,12.5 to the points on the wired side but only 1.5 on the points side that is on the cam.

Would I still have aprk on the HT lead to the Dist Cap regardless of the points, or do I need good points for spark from the coil?

 

[TR3driver]

I am getting voltage,12.5 to the points on the wired side but only 1.5 on the points side that is on the cam.

I'm not sure I understand that statement. But if you can measure different voltages on either side of the points, with the points closed, then the points themselves are bad.

Would I still have aprk on the HT lead to the Dist Cap regardless of the points, or do I need good points for spark from the coil?

The spark is created by the action of the points, so they are pretty much essential.

In a nutshell, while the points are closed, current flows through the primary of the coil, building up a magnetic field in the metal armature inside the coil. When the points open, interrupting the current, the magnetic field collapses quickly, inducing a high voltage into the secondary winding. With luck the secondary voltage goes high enough to jump the gap at the plug (and between the rotor & dizzy cap), thereby creating the spark.

 

[80spit]

I think I found the problem, it was the wire from the condenser to the points.

Thanks everyone for the assistance.

I have had this car for three years and this was the first time it has broken down so I was looking for major problems instead of the minor items.

I will now carry a spare set of points and condenser at all times.

I still have too much voltage to the points, about 8.5 volts even with ballast resistor installed but I will work on that one after I am sure I have this issue solved.

Thanks