Hi everyone. I just picked up a 93 940 sedan. Super clean car! Got it real cheap. (Because it didn't run) I did a little research on it before I picked it up. Everything seemed to point to the fuel pump relay. I get it home and diag. The fuel system, and all is well. Upon further investigation, I find no power to the coil. As well as the obd system not working. So now, I'm really confused. Anyone have any ideas?

 

Yes you are new and "New Member" is where you introduce yourself and your car, not for technical problems. Might be why no one has jumped in to help.

Moved your post to the 940 section.

 

Thanks for the heads up. I was a little confused when I first signed up. It wasn't till after I posted that I saw the "new members" sticky. It looks like I have one power to The coil (blue wire) but none of the other wires are hot. The black wire tests good for ground. In my mind, This tells me the coil is no good. Am I off base here? Or is there more to it?

 

Ok, I'm assuming your 1993 is non-turbo, and a Bosch system (some 1993's had Regina/Rex fuel injection/ignition, these are quite different. a Regina car will have a square coil that looks like a transformer, while a Bosch car has a conventional 'beer can' coil....

the blue wire comes right off the ignition switch to pin 15 of the coil.

the red-white wire to coil pin 1 comes from the ignition amplifier aka power module, this is selectively grounded to fire the spark. This ignition amplifier is a 5 pin flat module thing bolted to the inside of the left fender, behind the headlight, and near the air filter box.

the amplifier gets power on pin 4 (blue) when the ignition is switched on. ground on pin 2 (black). control signal from the ICU (Ignition Control Unit) on a shielded grey wire to pin 5, the shield of this wire is connected to pin 3. pin 1 is the aforementioned red-white wire to the coil.

if you replace the ignition amplifier, be sure to use heat sink paste between it and its mounting surface, this helps cool it. clean the mounting surface first.

 

That's awesome! Thanks for the clarification. It seems I have the Regina setup. Although, there is no module behind the headlight but there is one directly under the transformer style coil. I'm assuming the coil is bolted directly to it. There is also a small unit bolted to the left strut brace. I'm guessing It's the radio suppression doodad. (The name escapes me). Is there a way to test the module? I'm so opposed to just throwing parts at it.. I'll try to post a pic. It also looks like there is a single tab in the middle where something would connect.

 

yeah, regina/rex is different, the power amplifier module is integrated into the coil.

left connector: blue wire at pin A is power. black wire at pin B is ground. red-white wire on pin C is to the tach.

middle connector: grey wire at pin B is signal from ICU. brown wire at pin A is signal ground.

drawing shows another 3-wire connector on the right with nothing connected.

 

Ok. I found a module at autozoo for $111. But jcwhitney has a stacked module/coil for $22! At that price I can afford to try it.

 

a generic chinese 'stacked module/coil' would not be what I'd even consider putting here.

first, confirm you DO have power at the blue wire when the ignition is on? no power, its not the coils fault. if there's power, continue...

second, hook a test light up to the grey signal wire and ground, and crank the car, does this test light blink? if no, then the problem is NOT the coil, its something else (perhaps the crankshaft position sensor?). if there's pulsing, continue.

finally, pull a spark plug, connect it to its wire, and hold it with insulated pliers so the metal side of the plug is firmly grounded against a valve cover bolt, and have someone crank the car, verify you see or don't see a fat blue spark in the plug. if you see a spark, your ignition system is working. no spark but above tests good, then and only then you may need a new Rex coil.

this is the correct coil to use for a regina/rex car.
https://www.fcpeuro.com/products/vol...40-940-1367438