The duty of the ballast resistor is to limit voltage to the ignition coil. … A quick and easy way to diagnose ballast resistor failure is to bypass it by
running a temporary jumper wire from the battery to the coil
.
Can I remove the ballast resistor?
In either type of ignition system, points or electronic, the ballast resistor can
be removed to increase secondary voltage to the spark plugs
, but the long-term effects of removing the resistor differ between the two systems. … On the left is a factory style resistor; on the right, an aftermarket unit.
Can you bypass a resistor?
A wire in the left circuit is shorting the 100Ω resistor.
All current will bypass the resistor
and travel through the short. The voltage across the 100Ω resistor is going to be zero.
How can you tell if a ballast resistor is bad?
- Vehicle starts, then immediately dies. The most obvious symptoms will be the vehicle starts, but then immediately dies as soon as you release the key. …
- Not starting at all. …
- Don’t jump the resistor. …
- Let the vehicle be.
Why is a ballast resistor needed?
A ballast resistor is
used in a circuit to limit the current and hence prevent it from over current faults
. Here, as the current in the circuit varies and increases above a particular threshold value, the resistance also starts to increase.
How do you know if a resistor is burnt?
Measure resistance from one end of the resistor to the damaged section
. Again measure the resistance from the damaged section to the other end of the resistor. Add these two values of resistances. This is the approximate value of the burnt resistor.
What happens when a resistor burns out?
When a resistor breaks down,
current typically flows through the burnt resistor without any resistance
and thereby passes unchecked. Other components in the circuit may become damaged from the excess current flowing through.
What happens if you don’t use a ballast resistor?
If the ballast resistor is not working properly,
the vehicle will not start
. Since it is an electrical system, it is something best left to the professionals to handle. The only way to have the vehicle up and running again is with a ballast resistor replacement.
What causes a ballast resistor to fail?
The resistance through the ballast resistor varies with current flow which varies with engine rpm. This naturally causes the
resistor to expand and contract from heat
. That’s why they eventually fail.
Do you need a resistor with a 12 volt coil?
If a 6 volt ignition system is converted to 12 volts and a Delco style 12 volt coil with an internal resistor is installed as part of the conversion,
no external resistors are required
. The 12 volt battery must be connected so the negative (-) battery terminal is connected to ground.
Where does a ballast resistor go?
Note: Ballast resistors are usually located
bolted to the firewall
if your distributor and/or coil is at the rear of the engine.
How do you test an ignition ballast resistor?
Measure the voltage (or check with a test light)
the voltage between the single wire and ground
. If there is power there, the ballast resistor is likely bad. Reconnect the wires and measure the voltage at the positive side of the coil. If you see 8-13 volts, you may have a bad coil.
What does a 12 volt ballast resistor do?
A Ballast Resistor is an
electrical device that reduces voltage to the coil so that more energy is available for the spark plugs during starting
.
What happens if I use the wrong resistor?
The equipment will cease to function in short order either by
the resistor itself burning up
, or by the heat it generates burning up an adjacent component or possibly the circuit board its mounted on or even foil pattern on the circuit board, or maybe all three.
What happens if I use a higher ohm resistor?
Ohm’s law defines a linear relationship between the voltage and the current in an electrical circuit. The resistor’s voltage drop and resistance set the DC current flow through the resistor. …
If we increase the voltage, the current will increase
. If we increase the resistance, the current will reduce.
