75' starts runs for a few minutes then dies

[EWHOLTZCLAW]

Ok I can do that in the morning. If I'm not getting power to the coil what could that mean?

 

[EWHOLTZCLAW]

Just curious what else it could be so if it's cheap I'll just get it at the parts house tomorrow

 

[Slowleak]

It could be your ignition switch, the pickup coil, or it may just be a bad/loose connection.

 

[EWHOLTZCLAW]

Ok so I just checked and I have no power to my coil when it's in the run position but I don't know about the start position cause I don't have enough hands to get That done right now. So what does that mean

 

[Slowleak]

If you have an early Duraspark system, the voltage to the coil is cut when the ignition module senses that the distributor is not turning. You would have to turn the key to start to get voltage. Duraspark II would have voltage with the ignition in run and the engine off but a Duraspark I would not. I am not sure which is in a '75.

Check your connections to the ignition module. Look for voltage at the coil when cranking. If there is no voltage when cranking then I would change the pickup coil. Ignition switch would be next on the list.

 

[EWHOLTZCLAW]

Ok cool thanks

 

[Seventee]

The pickup coil shouldn't affect whether or not there is voltage at the + side of the coil. Have you checked fuses?
Another quick test would be to run a jumper wire from the positive battery terminal to the + side of the coil. If it runs you know you have a wiring or connection issue somewhere.

 

[EWHOLTZCLAW]

I have no power at coil in run or during start and I just ran a jumper between battery and positive side of coil and it will not start

 

[Slowleak]

The pickup coil shouldn't affect whether or not there is voltage at the + side of the coil.

On early Durasparks the pickup coil tells the ECM that the distributor is spinning. The ECM then switches off power to the coil if it is not.

Jumper to the coil is a good test.

 

[Slowleak]

Could still be the pickup coil or bad connections to the Duraspark box.

 

[Slowleak]

This may help. I don't have any manuals on the 75 models and my 77 is different. http://classicbroncos.com/forums/attachment.php?attachmentid=264123&d=1341361815

 

[Seventee]

I have similar documentation, however I believe the current is controlled via the green wire on the "DEC" side of the coil through the 1-second timer, and there will still be voltage on the "BAT" side of the coil w/key on.

http://www.supermotors.net/getfile/189101/original/duraspark.jpg

 

[Slowleak]

You may be right. It puzzles me that the jumper did not work. If he is not getting power in the red wire to the coil then there is probably no power to the ECM. I'm still questioning wiring from the switch.

EW - with it switched on are you getting power thru the red wire going into the Duraspark box?

 

[EWHOLTZCLAW]

I'll have to check it out in the morning I'm at work now but it seems like if it's jumpered from the battery it shouldn't matter. Maybe I'm not understanding it right tho

 

[Slowleak]

Seems like it, but it has to get power to the box to start. If the box is getting power, then it gets really confusing because it should have started when the coil was jumpered. You may have a bad wire to the box or to the coil.

 

[EWHOLTZCLAW]

Right on I'll check it out in the morning and report back!

 

[EWHOLTZCLAW]

Ok the red wire has no voltage with the key on and the green wire has 7.2v that's going to the ignition module

 

[Slowleak]

Do you have one plug with three wires and one with four going into the box like the diagram below? Wire number 4 on the end, which shows as blue, should have power.
http://www.ford-trucks.com/forums/attachment.php?attachmentid=48601&d=1328618683

 

[Slowleak]

If that wire on the end is not getting 12v then i would check the wiring back to the switch and voltage to the switch.

 

[EWHOLTZCLAW]

I have 1 plug with 2 wires and 1 plug with 4 wires