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79 CA Hall Effect Ignition

Posted: Tue Jul 09, 2013 9:14 am
by airkooledchris
[Edit: from the July 6 & 7 thread in the 2013 Itinerary Forum, a technical discussion was born, starting here:]

is there no troubleshooting process for the hall setup?

Is the problem on the distributor side, or the firewall mounted portion of it?

Can it not be looked at and corrected by Philbin like any other rebuilt distributor?

Throwing away the new technology and going back to the old just because the newer stuff is less understood?
that's how FI busses end up with center mount Webers :rabbit:

Re: Utah July 6 & 7

Posted: Tue Jul 09, 2013 9:36 am
by Amskeptic
airkooledchris wrote:is there no troubleshooting process for the hall setup?

Is the problem on the distributor side, or the firewall mounted portion of it?

Can it not be looked at and corrected by Philbin like any other rebuilt distributor?

Throwing away the new technology and going back to the old just because the newer stuff is less understood?
that's how FI busses end up with center mount Webers :rabbit:
Oh my . . . .

There is a troubleshooting procedure for the firewall mounted ignition module AND a very brief troubleshooting test for the Hall Effect pick-up unit. Our troubleshooting test squarely put it on the module which was not delivering any voltage to the coil. Philbin cannot save a module. No one can.

Our philosophical discussion centered on the crazy places we find ourselves in our VWs. What would you do with your family in the middle of a hot outback if your CA-only ignition system failed? Would you put in a spare distributor with points and condenser and a blue coil? Hello.

My thinking in no way represents a "lack of understanding of the newer stuff". I have diagnosed and repaired coil pack Motronic M-60 BMWs and I still have this Electronic Everything Lexus. My last tow truck ride was with my 1994 VW Passat which up and died dead (under warranty, thankfully).
I don't like tow truck rides much.

I asked rallybug if he wanted the old air-cooled VW recipe of being able to repair on the road, and his answer was "yes". Me too! BobD stranded me in Los Alamos for fifteen minutes when the Pertronix let go with poisonous fumes of melting polychlorinated biphenyls. I am back to points and condenser and they are fine.

In my opinion, the Hall Effect electronic ignition system on the 1979 California VW bus was not an "integral part of the Volkswagen Bus mystique". It was VW's very last gasp effort to pass a single state emissions requirement.
Your thoughts?
Colin

Re: Utah July 6 & 7

Posted: Tue Jul 09, 2013 3:19 pm
by dingo
I think youre being way too reactive about the hall effect Ignition system. Its extremely durable and reliable.I have used it succesfully for years without problem. Its bulletproof and dead simple to diagnose. The module does have to be well heat-sinked...(the spare wheel cowling works for me) and well grounded.
I carry a couple spare modules but have never had to use them

Re: 79 CA Hall Effect Ignition

Posted: Fri Jul 12, 2013 11:17 am
by airkooledchris
im all for ditching this if they are known to be common failure points (pun intended), but this is the first thread ive read (within the past 4 years) where one of these units was working and then failed.

of the 5 warnings they list with this setup in the Bentley, I ignore 3 of them completely.

#3 - do not replace coil with the wrong one. ok, that makes sense - don't replace part A with part B or it won't work correctly.
#4 - don't connect a condenser like you would if you were using points. OK - another obvious one. you should also not cram points inside of the distributor since it doesn't use them.
#5 - do not connect a quick-charge battery charger for boost starting for longer than a minute. long operation with excessive current will damage electronic components of the ignition. since ive never done this to any vehicle ive owned I probably won't start now.

FWIW ive broken rule #1 many times without a problem and #2 is a non-issue for me as I have a push button I can use to crank over the motor with the ignition off.



All that said, the unit IS old at this point. Perhaps they will all start failing soon as they reach the end of their expected life cycle. Perhaps it IS a good idea to keep your spare coil/distributor/points in the toolbox when on a longer trip. (ive done this on both of our Maupin trips, but otherwise I leave it at home.)

Re: 79 CA Hall Effect Ignition

Posted: Mon Jul 15, 2013 9:01 am
by airkooledchris
Is there any valuable data to be had for those who run these systems?

Other than they work extremely well most of the time, but if it happens to fail - your screwed without a backup coil/dist/points Vs the more easily swapped out points?

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 9:01 am
by rallybug
My contact here didn't have a Fed distributor (021-905-205 P/022-905-205 S) and Busted Bus want $199 for one, which isn't on the cards right now. I checked TS classifieds and nothing currently, so ended up ordering a new ignition module from Bus Depot to try and get me back moving until the dizzy appears.

Added the thermal paste to the back, attached it to the heat sink, plugged it in, attached the wire to the double relay connector, the connector to the side of the CA-spec distributor and tried to start. Nada, just turns over without catching. The ground wire is currently still attached to the block using the tinware bolt that Colin appropriated - not sure if that is correct, or if I've missed something out in re-connecting it all :scratch:

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 10:03 am
by Amskeptic
rallybug wrote:My contact here didn't have a Fed distributor (021-905-205 P/022-905-205 S) and Busted Bus want $199 for one, which isn't on the cards right now. I checked TS classifieds and nothing currently, so ended up ordering a new ignition module from Bus Depot to try and get me back moving until the dizzy appears.

Added the thermal paste to the back, attached it to the heat sink, plugged it in, attached the wire to the double relay connector, the connector to the side of the CA-spec distributor and tried to start. Nada, just turns over without catching. The ground wire is currently still attached to the block using the tinware bolt that Colin appropriated - not sure if that is correct, or if I've missed something out in re-connecting it all :scratch:
I am sorry to hear this. The ignition module is getting 12 volts from the connector that comes from the double relay? Try the Bentley troubleshooting test that we performed, the one demanding 12 volts to the coil, remember? It was the test that warned you to shut off the ignition if it showed low voltage because "things would happen". Check continuity through each of the three wires from the module to the distributor. Check the terminal fingers at the distributor plug.
I put up a post in the Electrical Forum, "'79 Hall Effect Ignition" where we might have some Hall Effect distributor troubleshooting tips for you. You can also PM dingo and ask him for help, I am only able to go as far as the Bentley manual.
ColinInHendersonNV

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 3:46 pm
by rallybug
So, 12v at coil with ht cable removed from distributor and grounded, 3-point plug removed:

Image

Pushed a panel pin into the middle (green/white) connector on the 3-point distributor connector and connected via test lead to ground, turned ignition back on, 12.5v again. Removed ground lead connection, voltage dropped to about 7v before going back to 12.5v (little pop when I removed the ground lead from the 3-point connector...).

That ends the ignition control unit test in the Bentley as successful.

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 4:10 pm
by rallybug
Checked the 3-point distributor connector and noticed that the outer two point had four fingers showing, but the middle (green/white) only had three:

Image

Teased it out with a pin, re-connected plug and tried to re-start. Still just turning over, not catching.

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 4:27 pm
by rallybug
Set multimeter to 2000ohms for continuity testing, unplugged the plug from the ignition control unit and put the multimeter leads on the appropriate connectors there and on the 3-point distributor plug.

Readout stayed as 1.

Tried the green lead connector in plug to coil, readout stayed at 1.

Unless I'm doing something silly, I think that means no continuity from the ICU plug to the dizzy or coil, doesn't it?

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 4:42 pm
by rallybug
So, I noticed something when checking the Bentley. Here's the wiring diagram for the ICU:

Image

It goes blank, green, brown, brown/white, green/white, red/black, black.

Now, here's my ICU plug connections:

Image

Granted, I'm holding it the other way round, but the connections go blank, green/white, red/black, black, brown/white, brown, green.

That seems messed up, doesn't it?

[Edit]Did the continuity test again, this time with the dust cap off so that I can see which color wire goes to which terminal on the ICU plug - green, brown, black and green/white all show continuity - red/black and brown/white do not. I checked with one probe onto the end of the wire at the plug (rather than the ICU end, but still no continuity.

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 9:34 pm
by Amskeptic
rallybug wrote: Bentley - blank, green, brown, brown/white, green/white, red/black, black.

my ICU plug connections
Granted, I'm holding it the other way round, but the connections go blank, green/white, red/black, black, brown/white, brown, green.
That seems messed up, doesn't it?

Did the continuity test again - red/black and brown/white no continuity.
We DID have a running bus enjoying our test drive with the California double relay newly hooked up. So however the wiring appeared at the plug to the module did work. Are there any terminal designations on the new ignition module where you can verify positioning? Exact same module as your old one?

I am much more curious about the lack of continuity with brown/white red/black through the harness??


PREVAIL!!
Colin

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 9:45 pm
by rallybug
Continuity search will be tomorrow's task, I think - the fact that it was running great leads to the Bentley diagram not being right for this bus, somehow, so I'm more inclined to believe the wire(s) at fault.

Re: 79 CA Hall Effect Ignition

Posted: Tue Jul 16, 2013 10:50 pm
by Amskeptic
rallybug wrote:Continuity search will be tomorrow's task, I think - the fact that it was running great leads to the Bentley diagram not being right for this bus, somehow, so I'm more inclined to believe the wire(s) at fault.
Here, some reading . . .

http://www.wellsve.com/sft503/Counterpoint3_1.pdf

Re: 79 CA Hall Effect Ignition

Posted: Sun Jul 21, 2013 7:43 am
by dtrumbo
Keep in mind that the drawings in the Bentley manual are schematic diagrams and not necessarily "blueprints". They are drawn for simplicity to show how one thing is electrically connected to another thing which is rarely how one thing is physically connected to another thing. I was fooled by this when I got my first bus and the fuse box diagram wasn't drawn as it appears in the physical world.

As Colin said, PREVAIL!