'86 T-type ignition moduel


New Member
How do you check/test the ignition module which is connected beneath the triple coil pack (this is the unit that has the 14 pin connector) and prove good or not? Mine has battery voltage to pin M (#839) when key is on. Goes away when key off.

Have been told that Casper's sells a tester. Lot of money for that. Not sure how it would prove ignition module good if the coil pack was bad and would not light the test windows. How would you know? I guess by buying a new coil pack and then use the tester again to see if it works. Then if not, then buy new ignition module and see if that made it test good. Or, buy new coil/ignition module from the get go and then would not need the tester, if the new parts are good.

Sounds like throwing a lot of money around and hoping to see flying pigs.

Anyone have any other, cheaper ideas?
Ok. No takers on that. I did find out what the problem was, though, and fixed it.

Care to share what the problem/solution is/was? It could help people in the future. BTW I am pretty sure there are some members in the Dallas area that can help you out with future problems. It was crazy to me when I started how willing people are to help (I hate feeling like a mooch), but you just have to hope in your mind you'll help people out one day the way people helped you in the past.
Would be happy to share what little I know, but this is going to be a rather long post, so prop your eyelids open.

First, Steve Wood's website Vortex Buicks is a valuable resource for troubleshooting. The Turbo Regal website Turbo Regal Web Site also has a troubleshooting section. I used the Steve Wood site, because the information was grouped better to my liking.

After following the no start flowchart step by step, indications were that the ignition module was probably at fault. But, the coil pack could have been a problem, also, since the injectors would fire, but no spark. Either the module or the coil pack or both could be bad.

I determined that injectors were working by pulling off one of the electrical connectors, and checking for voltage across the connector terminals with an analog vom on low voltage range while cranking engine. If ok, you can see a blip on the meter needle when the the voltage pulses. There will be no movement if there is no pulse. A digital meter is not fast enough to register a pulse. You can also use a Noid test lamp instead of a vom. I wouldn't try to use a regular 12v bulb, since the filaments probably would not light with such a short pulse. Being cheap and having a vom handy, I used it instead of paying for a Noid kit. Afterward, pulling a spark plug and observing that it was wet with gas helped verify operation.

To eliminate one possibility, I removed the coil pack from the ignition module and tested the coil pack with a digital volt meter (analog vom would also work). Check secondary (top post terminals) by measuring resistance across 1-4, 2-5, and 3-6 packs. From what I've gleened from web search, secondary should be about 12K ohms or so on this car. Mine was in very close range, except for the 2-5 pack, which measured about 25% higher at 15K ohms. That should still be useable and fire the plugs, even though the spark might be a little weaker on that pack.

Next, I checked the corresponding primaries on the bottom side of the pack which should be less than one ohm each. Mine was .9 ohm across each, well within range.

An open across any of the above measurements means the coil is unuseable. Throw in the trash. This is a cheap, quick and dirty test, but I felt all coil packs were alright.

All fuses were good, so was probably some internal fault of the module.

The ignition module was filled with sticky goo which was probably the dialectric which melted after an overheat condition after failing. I'm just guessing here. But what a mess! I cleaned off the spade terminals and took the module to O'Reilly's who have a coil/module tester which performs five or six different tests. My module could not even start the first test.

The store had a BWD brand module in stock. It is made in U.S.A., but that really doesn't mean much anymore. They put it on the machine, and all tests ran successfully. They let it cycle three times and it passed each test each time.

I took it home, slapped the coil and module together (be careful to get the spade connectors in the right places), and buttoned up everything. Turned the key.....fired right up. Muy bueno.

Have heard that some aftermarket modules can malfunction and set a code 42. To check for this, I shorted the ALDL connector A and B terminals with a paper clip and looked for any set codes while the SES dash light did its semaphore signaling. The only code was 12, which repeated itself continuously, indicating normal operation.

I'm not trying to be condescending here, but I'm assuming the reader knows the difference in voltage, current, and resistance. Be careful which function is dialed in on the vom or dvm, i.e. don't try to read voltage on the resistance scale, or vice versa.

That's all there is. Hopefully it will run tomorrow, although who knows with these old cars?
BTW, I saw on your signature line that you have a 3200 stall converter. How do you like it? I've thought for years about putting on a higher stall unit.

When car was just a few years old, the converter failed. I was visiting in a small town and had to let the local GM dealer fix it. It did not perform at the same level after that. Later when doing some work underneath I pulled off the inspection plate and found that my converter did not have the D5D5D5 marking. The dealer had put on a regular low stall Regal converter.

At highway speeds and regular around town driving, it is ok. But you can't break the tires loose until the turbo spools way up. Of course the famous hard shift from low to second leaves plenty black stuff on the street. Still would like a harder launch at times.

Is your's a lock up type? What brand? Always wanted to know if a high stall means you cannot move off until the rpm gets up real close to stall speed.

What say?
I'm not really sure which brand my converter is. It is a non-lockup, but if I could go back I would get a tighter stall, lock-up, and ball bearing turbo.
i took of the ignitionl module and hade a crack bought a new one and a new coil and still won't start i bought the module from autozone