Continuing to track down source of no voltage to coil while cranking

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shanker

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Car I'm working on is a 75 Duster 360. (5 wire ECU w/ Dual Ballast)

It has an intermittent issue that'll cause it to crank and them immediately fire off when the key returns to the run position.

Yesterday I replaced the ignition switch and hoped that it would solve it as it was the last piece of the ignition system that's not recently either replaced or tested on another vehicle for function to verify it's good.

Because the issue is intermittent I am thinking it's a connection issue. Attached is a picture from the 1975 FSM showing the wiring diagram, the two arrows " >> " according to the legend indication a connector, but can someone shed some light onto what "CE 2" may reference? (My pliers are being used as a pointer in the picture)

IGN Wiring.jpg
 
The brown wire that comes out of the ignition switch powers the coil during "start". The brown wire bypasses the ballast. As soon as you let off the key, power jumps to the blue wire that comes out of the ignition switch. Since you said the engine starts when you release the key, this means the problem is on the brown wire. Since the ballast is bypassed during "start" the problem isn't there. Start testing all the connections on the brown wire. Start at the ignition switch connecter, then both sides of the bulkhead. The brown wire ends at the ballast.
 
J2 DBL* is probably the feed wire. I'd guess CE2 is the bu;lkhead multiconnector. If so there is a seperate diagram just for it.
 
This may be a situation where the problem can be narrowed down with continuity tests.
It can be done with an ohmeter/continuity tester or a test light.
I'll assume the first.
Disconnect the battery neg and positive!
1. Clip one lead to battery feed wire (at positive terminal or at the starter relay) and the other lead to the J3 14 Brown wire. It does not have to be connected to the 1/2 ohm ballast resistor.
Turn the key to start and hold it.
Is there good continuity (zero resistance) ?
If not, then do the same test for J3 at the bulkhead.
If yes, reconnect J3 14 Brown to the 1/2 ohm resistor. The clip the tester to the other side of the 1/2 ohm resistor. Turn the start key and hold it long enough to measure the resistance or prove continuity.

Continue following the wires and testing in which ever direction there is no continuity.

One question I have. Where does J3 16 Brown connect?

OK two questions. Did the ammeter show anything unusual when you where attempting to start the car? It should have shown small movement - maybe 5 amps discharging. Less would suggest power is not going through to the ignition. More would suggest a short drawing power away from the ignition coil and ECU.
 
Mattax said:
One question I have. Where does J3 16 Brown connect?
Click to expand...

That diagram is somewhat confusing. The brown wire(J3 16) should start at the ignition switch and should end at the output end of the ballast.(bypassing the ballast during start) The brown wire should connect directly to the blue wire at the ballast. The blue wire then runs to the coil.

That is how I've always seen them. The brown wire changes to blue at the ballast and then runs to the coil. Maybe they changed it in 75? Can the OP post a picture of the ballast and all the wires that are attached to it?
 
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J3 14Brown is the heaviest wire, so that leg is almost certainly the feed.
Two wire junctions at the terminal crimps are common, but it sems that when 3 wire junctions were needed they would often use a splice rather than two, two wire crimps at terminals.
 
My 886 Power Wagon ran fine parked it for 3 or 4 weeks # went to crank it and nothing but when u released ignition switch it would fire.
Doesn't make sense and some will say BS but I noticed voltage regulator melted and popped a fuse replaced both and been running fine ever sense !
 
J3 14 br leaves ignition switch and goes to first splice, branch goes to seat belt starter interlock page 14-18 cordinates 17 E. Next to CE 2 bulkhead connector ,Next is 3 way splice page 14-15 6 E as seen in your picture
 
Bugman said:
J3 14 br leaves ignition switch and goes to first splice, branch goes to seat belt starter interlock page 14-18 cordinates 17 E. Next to CE 2 bulkhead connector ,Next is 3 way splice page 14-15 6 E as seen in your picture
Click to expand...
Makes sense but starter interlock on a '75 ? Could be. I'm just asking. I had a '75 without.
 
3 way splice to coil postive and ignition ballast resistor,third branch circuit change to J3 18 BR goes to starter interlock switch, 14-17 15 B all possiable fail points
 
Other than little "glitches" like an early early 75 with a 74 interlock (who knows) the ignition switch/ start/ run/ bypass stuff always worked the same

The "usually brown" IGN2 comes off a contact in the ign switch and is ONLY hot during start. It goes through the ignition switch connector, the bulkhead connector, and off to the coil + end of the ballast. There should not be much in that circuit.

I was unaware that the ign2 ever went through the interlock. It has always been the "start" wire (normally yellow) I see in the diagram that the brown is branched off to the interlock box to provide a signal, but it should not be series/ broken by anything there

OP: The oval symbols with CE-x, CI-x etc are connector numbering. Go on several pages in the manual past the diagrams, and there are some charts in there. They show what those connectors look like and how they are wired, and a location description
 
The path. According to my diagram, J3 comes off the coil, goes through connector CE-37, then branches off three ways

One branch goes to the ballast, One goes up to (I can't read) either CE30 or CE39, the starter interlock switch, but that goes TO it it is not series broken there. One continues to CI38, the seat belt interlock box under the dash but it goes TO that and is not series broken
branches off and continues, finally, to CI-1, the ignition switch connector.

So it seems to me you are fighting a bad connector, most likely either ignition switch, bulkhead connector,

NOTE THAT THE PREVIOUS MENTIONED CE-37 IS THE MUCH DREADED ignition harness connector, normally white, in the engine bay that separates the engine from the rest of the underhood harness. Member Redfish has pointed out a number of times that THESE ARE TROUBLE



CE-37.jpg
 
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CE2, the bulkhead connector This diagram in my book is on page 14-31

Connectors such as CE mean, "connector, engine bay" and CI either mean "interior" or "instrument panel"

ce2.jpg
 
FOUND IT! and I feel like such a dope, I read every reply to this thread twice, made some notes in my own FSM and even drew out the wire trace with a brown sharpie. I feel like a dope because I started in the engine bay and worked backwards checking continuity as suggested and didn't find an issue until I got to the ignition switch connector.

Luckily I've got the terminals to rebuild the dash harness side of it which I've done.

Ignition Switch Wiring 01.jpg
 
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