Not Getting 12 Volts at Coil

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Yep, the sound you hear is the advance weights.
When my car was acting up, it had a real week spark when it was turned over with the starter with a plug out. But when I turned the dist. over slowly by hand, it had a much brighter spark. The only differance was the starter. Took it out and had it tested. It still turned over but had a short in it.
It sounds like your on the right track replacing the coil pickup.
 
Bob, did you have a mechanic or an electrician test your starter? I plan to have mine tested looking for a possible short.

Thank you for your help. I'm narrowing this down.
 
I took my starter to a Murry's auto parts store to have it tested. I think an Auto Zone can do it also.
 
i didnt read all the posts but iread enouh if the car ran before it was painted and before it sat the first thing I would look at would be all the grounds or if you put that orange box on thy are junk ive had 3bad ones but the GROUNDS are very inportant.. just trying to help.........
 
No orange box. It looks just like the original MOPAR box (black) that came on the car in 1974 when I bought it. I learned today the Mopar boxes are made in China and are junk. I ordered a Standard Bluestreak ECU. Should be in tomorrow.I think I have checked my grounds. Instructions on testing grounds from some of you would help.
 
Wow!! Could this be that the cap and rotor are not working together, Is the rotor to short and or is the cap to tall. This is weird, Good luck DartSport.
 
I have all old mopars with points, condenser and coil. some of your newer type ignition systems did away with the coil. You aren't running electronic ignition through a coil that isn't supposed to be there are you? just a stab in the dark that somebody else may know more about.
 
out of old book my truck just did the same thing tryed a new ecu nothin changed my pickup coil fired right up

copy good.jpg


copy.jpg
 
I previously posted the results of testing my coil. I asked if the results proved the coil good or bad. Here it is again. Someone???????

Checking Primary Resistance
20k - 0.00
200k - 00.0
200 - 2.0
2000 - 002

Checking Secondary Resistance
20k - 9.22 to 9.23
200k - 9.1
200 - Nothing
2000 - Nothing


Is the coil good or bad?
 
1974DartSport said:
Is the coil good or bad?
Click to expand...
Those numbers seem okay. Have you swapped in the new ECU? I've been reading over this thread for a bit and I'm not sure what hasn't been suggested. One thing that bears repeating: make sure you have good grounds.

I'll kick this around in my head and pop back in with any "Oh crap! That could be it!" sorts of things. Electrical issues drive us all to the brink of madness. Hang in there.
 
I towed the car to a local mechanic this morning who said he was good with electrical problems. I have spent many months tracing wires, changing parts, and I still don't have spark at the plugs. I'll let you know what he finds.
 
Well the Dart has been at the shop for a week now. I drive by every day and I've stopped in twice. I know the owner and his assistant are working on it. He hasn't gotten it running yet, however he told me "you have a hell of a problem here." I already knew that.

When it runs, I'll let everyone know.
 
Use process of elimination...
Take out the ECU and electronic ignition distributor. Put in and wire it up for a points distributor. See if it will fire.
 
Kudos for taking such a thorough approach to diagnostics., and not that you need "one more opinion" but...

When the car ran for a few seconds, did anything happen to kill it? At this point I would have begun to suspect that the timing had jumped or valves stuck open, compression gone for some reason, etc... except that your diagnostics pointed to a real problem. No spark on some of the wires. That is the most critical item to correct and it was never resolved. It appears the shop is having issues with this also. Did you ever test the old pickup, or put in a new one? (btw a brass feeler gauge is just to keep the gauge from "sticking" to the magnet for ease/accuracy of checking gap). If the pickup is good and the coil has 10+ volts, then the only other animals that could affect "some" of the spark is the distributor (metal trigger star damaged or shaft warped so much that the gap is too wide to trigger on one side and maybe too close on the other), the cap(cracked), the rotor(unlikely if you get spark on at least one wire), or the brain box. If the dizzy is damaged you may have had other internal oh-no's. If you have voltage issues to the coil, you may have issues with feeds too/from the brain as well. I don't know if this could have created the problem you have but it would certainly manifest somehow.

The mechanical "hot wired" distributor approach may circumvent the problem if electrical, and I am sure it would be great to have it running… or at least prove that the problem is elsewhere, but there is still an issue with the electronics that would have to be addressed.

’74 Sport is correct. Use the "process of elimination" approach but be sure you follow each trail to the end, verifying every component in the chain and stating with the most simple and inexpensive items first. You started out on this path with the electronics but may have abandoned it in frustration just as you were closing in on the solution. It may be the shop’s problem now and I hope it doesn’t come back to you broken still, but there is an answer no matter how obscure (or simple) it turns out to be.

I will be waiting for this one’s resolution.
 
fstfish66 said:
that makes me think,,its gonna be pricy to get it back
Click to expand...

I was told $1068.00. See below. Now you know why I was spent so much time asking for abodiesonly member's help. OUUUUUCH!

At 4:30 this afternoon, I received a phone call from the mechanic who has had my Dart for the past two weeks. Many of you who have followed my posts know the headache and time I put into getting this car to run. Unfortunately I could not get to the shop before 5:00 close, so it will be Monday before I retrieve the car.

The mechanic is Eric. He is in his early fifties and claims he is familiar with the 74 cars. The first thing he told me was the car would not crank because the ECU was dead. He had to replace it. Very odd. Two days before I took the car to him I put a brand new Standard Bluestreak 5 pin ECU on the car. This was the third ECU I tried in many months of attempting to get the car to run. He put in the fourth ECU and disconnected the wiring connector that plugs into the seatbelt interlock unit on the driver side fender between the ballast resistor and the wiper fluid bottle and the engine fired and ran. He told me he reinstalled my Bluestreak ECU and it would not fire. He seems to think the Bluestreak went bad because he thinks there is a short in the seatbelt interlock unit and I probably ruined the Bluestreak by many attempted cranks prior to taking the car to him. He advised me not to re-plug the interlock unit for fear it may short the fourth (good) ECU.

Does this sound correct? Could that damn interlock short out three previous ECUs?

He also changed the neutral safety switch. I'm not sure if it was the switch or the plug. I'll find out Monday.

One think that struck me as odd was Eric mentioned the car would crank yet not fire until he disabled the interlock unit. Many of you will remember that in 1974 (and a short time for the 75 models) you had to fasten your seatbelt in order to start the engine. If you turned the key off, you had to unfasten the belt and then fasten it again prior to cranking. Eric did not know this and he never unfastened and rebuckled the seatbelt. I used to hate that damn interlock, however I never disconnected it. I just plugged the middle passenger belt (bench seat) into the driver buckle to start the engine.

As strange as this may sound to many of you, I want that interlock unit to work properly. I want to reconnect it, however if Eric is correct that doing so will fry the ECU, then I will not reconnect it. Anybody know if Eric is right?
 
Ouch is right! I hope I am not wasting bandwidth here as I don't actually know how the interlock circuit is wired, but as tenatious as you were at the rest of the wiring I would suspect that a schematic and your multi-meter could "Verify" the circuit and components of the interlock are correct.

At it's heart there must be a relay of some sort that grounds with the buckle engaged but I don't remember the unbuckle-rebuckle being required, just that the buckle needed to completed the relay ground. I would guess that the positive side of the circuit kills the power to the ECU so it likely does connect to it directly in some way thus the warning to leave unplugged (or fix it to be correct) is advised.

Its a shame this was so expensive but hopefully once you get some road time in your car the memory of lost $$ will fade quickly.
 
well ive never heard of this inter locking unit,,makes me wonder why now with all the seat belt laws,,that that unit must of had a ton of problems,,or they would have them in new cars today,,,

how your mechanic ever found that my guess was by mistake,if you say he never heard of it,,after he told you he was familiar with the 74/75 cars,,,

so to unplug a plug,,,replace the ECU,, and a new netural switch 1 grand,,,,,holy crap,,i think ide try to bargan with him,,,sounds was out of line,,,unless he charges 250 bucks a half hour of labor,,,

go buy another ECU,, put it in the car,,reconnect your seat belt deal,,and try to start the car,, then disconnect it,,,and put the good ECU back in if it frys it,,, maybe look under the seat see where all this seat belt stuf is hooked up,,may be a frayed wire,,in the system,,at the fire wall of under the seats,,,my guess the wiring under the seat is where the trouble is ,,if its realy that causing all this hoopla,,
 
So. What happened!? Dang this was a good thread. I wonder if it was ever fixed. I wonder if the "Mechanic" took out all the "pointless" factory wiring and ran a 00 gauge wire from the battery to the coil, then on to the ecu with nothing more than a knife switch to disable the engine .
 

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Wow... I never even thought of the interlock. My '74 Cuda had one, it was disabled. Apparently disabling was common because a few books or groceries on the pass side seat would be enough to activate it. My apologies, I never even thought about it. It does sound like he had to do some digging to figure it out. It doesnt take too many hours to reach numbers like that. I do not believe the interlock could "spike" the module, but then again, I'm not very familiar with it or it's wiring. So that's more of an uneducated opinion rather than a definitive statement on my part... However, probing, grounding, or a surge in the positive battery circuit with the key on could pop a new one.
 
I read a long way thru this post wondering if anyone would mention the interlock. This is typical for these cars. First thing I check. Everyone I ever had went bad.
 
There is no damn way that an interlock system could damage the ignition system. Period. End. Stop.
 
From what I remember last night reading this... The car would crank but did not have spark. So, interlock would not be the issue. Right? The interlock prevents the starter from activating.
 
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