Replacing Coil

[militarypotts]

I've got to replace my coil I believe. Stupid me left my ignition switch in the on position, after showing a friend the truck. It is my understanding that even if the truck restarts after charging the batteries, the coil still could go bad in a week or two. Any tips I might need, or comments on this situation would be greatly appreciated. I've got the new coil, just alittle cold to work in the garage. Not a daily driver, so no big hurry. Seems like this is a fairly cut and dried procedure. Thanks.

[bump_r]

simple job, some have internal resistors, some external - I beleive they're interchangeable.

Someone oughtta move this to the "stock" topic...

[brute4c]

If it had an external resistor and you go to one with the resistor in the coil, get rid of the external resistor.

If you did not have the external resistor and the new one needs one, it will be marked on the side of the coil, then you will need to add one into the circuit.

[hiker]

Most of the later M-series coils have a built-in internal resistor. The older M-series coils that have the external resistor, will have it underneath the coil when you remove it. It looks like a disk (the same diameter as the coil) with two wires coming out of it.

[militarypotts]

Thanks for the info. I'll proceed with the operation.

[militarypotts]

The disk under the coil, isn't that called the ballast? Is this to be left in, or taken out. I'll have to look at my coil again, but I don't believe it says anything on the sides or bottom, which leads me to believe it has a internal resistor. Does this then mean that the ballast needs to be removed? A little confusing to me.

[hiker]

After removing the old coil, compair the length with the new one. Coils that require the external ballast resistor are much shorter. If the old coil is one of those, remove the ballast resistor and install the longer internal resistor coil that you bought. You'll see a noticeable difference between the two styles. The internal resistor coil will not fit into the distributor housing with the ballast resistor still in place.

[militarypotts]

Thanks Hiker, that clears things up. Compare the length of the new coil to the old. Basically, a shorter coil needs the ballast plate under it. an internal resistor coil would be to long for the housing. Got it! Thanks alot.

[militarypotts]

One other question Hiker, should the need arise to remove the ballast, does it just lift out, or is it mounted in some way? I'm very mechanically minded, but as you can tell, not so much in electronic workings of the vehicle. Thanks for your help again.

[brute4c]

It is just sitting in the housing...you can pick it up with the wires, if so equipped.