How to kill a distributor module

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V8 burble
Posts: 278
Joined: Thu Sep 03, 2009 10:13 am

How to kill a distributor module

Post by V8 burble » Fri May 11, 2012 11:56 am

I cannot say for certain what it was that caused my distributor ignition control module to blow, but I suspect either a bad earth, using a battery booster, or using a dynamo instead of an alternator.

The replacement module came with a list as long as your arm of the numerous ways you can kill a module.

1) The most common cause is one or more bad (ineffective or inadequate) earths (battery to body, body to engine, distributor to body/block). All contact surfaces must be clean, bright and shiny. It is also a good idea to add an extra earth wire from the distributor clip retaining screw to the block.
2) Always use an alternator not a dynamo.
3) Faulty charging system (stuck or shorted alternator).
4) Trying to start the engine using a battery booster-charger. Most of these have very dirty electrical signals which cause power surges or spikes. Disconnecting the battery, charging it, and then reconnecting it is the only correct way.
5) Using non-suppression plug wire leads. You must use suppression core type plug wires, not solid core wires (stainless steel or copper). Spiral core is best, but carbon core will also work.
6) High amp stereo equipment that is not properly earthed or the earths have not been updated to handle the added capacity.
7) Faulty starting system (excess starter drag, not enough voltage/amperage getting to the starter, worn brushes/armature). This includes a faulty battery or one with insufficient charge.
8) Incorrect ballast resistor or coil fitted.
9) Welding on the vehicle while the distributor harness is connected.
10) Direct shorts in the electrical system.

11) Never bypass the starter solenoid with wire or a screwdriver! The massive current may well cause serious damage to you and the car, never mind the module. Is your life only worth the cost of a new starter solenoid?
12) If you want to add some "protection", but not a guarantee, to prevent a voltage spike taking out your module, you can fit something similar to Mallory's Circuit Guard (in my case): http://www.summitracing.com/parts/MAA-29371/

**It is strongly recommended that the distributor's 3 wire connector is unplugged every time you do any electrical work on the Tiger. This will guarantee that you do not spike the module. The module does not kill itself. It is always some other component or human error that kills it.

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