Question

Why do the ignition control modules keep failing on my 1992 Chevy Silverado 1500 truck?

I have a 1992 Chevy Silverado 1500 truck and for the last 4 years it has been going through ignition control modules constantly.

I've ordered around $800.00 worth of ignition control modules from eBay and have had to replace them sometimes as soon as after 2 days to a month and sometimes as long as after 6 months.

I can't figure out what is going wrong with my truck causing the ignition control modules to fail and it's getting expensive and annoying too.

One ignition control module I put in sometimes lasts 2 days and then I put another in and it dies within a few weeks and some have lasted a few months.

Comments

Have you checked the wiring harness?  A short or bad connection could be frying the modules.  Also, make sure your battery and alternator are in good shape

Answer 1

Some reasons for an ignition control module to fail are heat, over voltage, bad voltage, voltage spikes, bad ignition coil and even bad spark plug wires or a bad distributor and pick up coil in the distributor.

Also be sure to put the thermal paste on the ignition control module bottom part that mates with the distributor to help dissipate heat or it can also kill the ignition control modules.

I use heatsink compound for computers and it works great and be sure to spread it out but not too thick.

I see you said you bought many ignition control modules from eBay and I'm gonna go out on a limb here and say that is most likely your problem if you have checked everything else out.

I've had the same issue with my 1990 Chevy Silverado truck and after it blew the original GM ignition module after several years I went the cheap route and bought an ignition control module off of eBay for aorund $15.00.

Well after installing that cheap ignition control module the truck started up fine and ran for a few days and then I went to Walmart to shop and came back out and the truck wouldn't start.

I figured it was probably the ignition control module that went out again and so I went to Autozone across the street from Walmart and got another cheap module to put in the truck to get it going.

Well a couple of weeks later the truck died.

I then bought a few more cheap aftermarket control modules and installed a new one and kept another one with me.

Around 3 days later the ignition module failed again.

So I finally decided to pay up the $100.00 and get a GM AC Delco ignition control module and put in my truck and it started up and actually ran better and the engine ran much smoother and was no longer running rich like it was with the aftermarket cheap Chinese control modules.

And so far 2 years later the truck is running fine and starting up all the time.

I replaced the old ignition coil as well as they can go bad and cause ignition control failure but even with the new ignition coil the cheap modules kept failing.

So I would recommend paying for the good GM AC Delco ignition control module as it will last longer and will help the engine run again.

The GM AC Delco ignition control modules contain a copper heatsink inside to help dissipate heat and a Variable Dwell circuit and they are also laser trimmed and have a large copper busbar.

I took the top off my cheap ignition control module and it didn't have the heatsink or large copper busbar and so I say it was the modules all along.