Car just died on me. cranks over but wont srart
The coil should have 3 wires connected to it. One is the big HT lead,
and then there are two small wires, one on either side of the coil. One
of the wires is for the constant 12volt power source, the other is the
control wire. With the ignition switched on, you should be able to read
12volts at one of these wires.
The other wire is the control
wire, it receives pulses from the ignition module that is inside the
distributor. Effectively this switches the output of the coil on and
off, and controls when the spark plug will fire. It is difficult to
detect these pulses without proper equipment, but a multimeter set to
AC might be able to detect the presence of an AC voltage (although it
probably wont accurately display the correct voltage), which would
indicate that the ignition module is working.
If the pulses are not present at the input of the coil, then your ignition module is probably the culprit.
Open the distributor, and remove the rotor button.
There is a round plastic cover over the ignition module, which must be
removed. The ignition module is semi circular, and has four wires
attached to it, via small screws. Take note of the location of each
wire, and unscrew each one. The ignition module can be unscrewed with a
phillips head screw driver, and removed. When fitting the replacement
module, you must cover it with the heat sink compound that is supplied
with the new module (mechanics sometimes refer to this compound as
ignition module grease). Without the heat sink compound, the new module
will over heat, and burn out. You should be able to replace the module
in 15 minutes, it is very easy to do.
Mar 05, 2009 |
1990 Mazda 323