HEI Conversion question

Just a little aside here, I retested the pickup coils. I got a resistance of 440 ohms, which is right in the middle of the testing range, and there was no continuity to ground at all.

Yes, where the red and blue wires meet, I read 1.41 volts coming from the connector that leads to the resistor/diodes.

With the C terminals disconnected, and B connected, I confirmed 12 volts on B. W terminal is unconnected. I remeasured the G terminal of the HEI unit without the black and yellow pickup wires connected to it, and got the same .01V.

I checked the ground post on the HEI unit for continuity to negative post of battery, and I really feel it has a good ground.

There's a nut between the aluminum piece and the HEI unit, which I added last night to see if that would improve my ground situation. The black/yellow wire from the kz wiring harness is a ground and connected to that post, so I believe the unit should be grounded through the bolt/nut. Do I need additional grounding? I have good continuity between that post and the battery negative ground. I also tested the little metal tab that sticks out of the top right of the HEI unit for ground and that was good too.

What is the voltage on the W terminal? I see you have red connectors on them. i presume that is to insulate the spade, so there is no wire or anything else touching the W terminal or the red connectors, correct?

What is the voltage on the little side tab?

Correct, those red connectors have no wires attached to them. I just didn't want them to touch anything,

With the ignition on, I am seeing the same .01 Volts on the W terminal and the little side tab.

Those modules look slightly different from the modules I usually get. It appears as though the W and G terminals have somehow ended up grounded.

I think at this point you should remove the modules from the bike and try to do a bench test with the battery. If I had a module with the captured nut, I would test it out, but I don't have one handy.

I would try to do the test using the push buttons. You don't need to actually get any push buttons, you can just touch the wires to the terminals.

The second test setup of this link:
home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

So basically, yu just wire things up and leave G (and W) un-connected, then just very briefly touch 12v to the G terminal. The spark will happen immediately, or just after. But remember, you are only touching it briefly... less than 1/4 second.

If you have coils with plug wires attached, just put a plug into each wire, and rubber band the spark plug bodies together so they stay in contact with each other. Spark plugs don't have to be grounded, they just need to touch each other.

I just realized, I don't have the wells DR100 modules. I'm an idiot. My friend at the parts store bought me what he said was a better quality one. Maybe this is screwing things up? The package says it is a BWD P-Series. Module CBE4P. Is this different than the Wells module?

Do you know if this is different? Should I pick up two Wells units and try it?

I've tried quite a few (some Borg Warner CBE4P included), and they all worked about the same. Back when I first developed this mod, the Wells modules were still made in Wisconsin and were basically ubiquitous. Other brands were just putting their name on the Wells-made modules, so they were all the same. Now everything is pretty much made in China, by a bunch of different manufacturers (as they all look different). So there is a chance that there are some non-conforming modules out there. But we know what they have to connect to, so we know how they should behave, for the most part. I think I tested the CBE4P to be the same as the DR100 in operation. I just don't have any currently handy.

The fact that the G terminal was able to pull down the pickup voltage to zero volts is very puzzling since that should be a very high-impedance input (which should not be able to do what it is doing, even if the module was dead).

With everything turned off and unconnected, can you measure the resistance between W and G, and each of those to battery ground?

Resistance between W and G = 9,860 ohms
Resistance between W and battery ground = 10,600 ohms
Resistance between G and battery ground = 19,420 ohms

This is with everything disconnected, but still hooked up the ground on the bike

The W to G reading looks ok. That's expected to be around 10k.

The other ones are not so good. The older module I have measures about 50 to 60 k from each, W and G, to ground.

If I had to guess, I would suspect the W terminal has somehow shorted to ground, or something in the current limit section has shorted, thus causing W to appear shorted.

But there is still something we're missing because even with W shorted internally, the voltage on G should not be able to get pulled down to zero. That is because of that 10 resistance. So I still suspect something external is not right.

I still think a bench test may be the best way to trouble shoot the modules.

OK, so i did the bench test. It didn't react immediately to the touch of the wire on the G terminal. I held it for maybe 1/2 second, then let off of it, then did it again. It worked about every 2 touches and made fat blue spark on the respective spark plugs. Does this tell us that the modules are good?

The module is not necessarily good, but is capable of making spark. The output portion of the module seems ok, but the input side and/or the current-limit/detection portion may be broke. When you are bench testing it, with power on, but nothing connected to W or G, what are the voltages on the pins? If G and W are still 0.1v (basically this counts as zero), then I would try new modules.

Start with the bench test before putting them on the bike, and pay cloase attention to the G terminal voltage when testing the new ones.

What I think could cause this is if the wires going to the B and C terminals were accidentally swapped for a time, or if a very high voltage were to be applied to the W or G terminals, and probably a bunch of other ways I can't think of. The modules have proven to be very reliable when used with the Kz's, but accidentally connecting them wrong can blow them up (I've let the smoke out of a few of them over the years while testing out ideas) :laugh: .

So i tested the old modules with nothing hooked up to the W and G terminals, and the W and G terminals showed 0 volts. So I got two new HEI units and hooked them up the same, and got 0 volts once again on W and G terminals. What does this tell us?