Help With Locating Ballast Resistor On '83

I've done a fairly thorough electrical check and found I'm not getting the roughly 6-9V hot into the ignition coil. This, of course, after I already replaced the ignition module and the distributor pick-up <_< I know the hot-into-coil circuit is the issue 'cuz running 12V hot from battery to ignition coil starts truck fine, but I don't want to run too long this way in fear of frying the coil.

My problem, I have no idea what the ballast resistor looks like/where it's located on this truck. And it's somewhat difficult to track the ignition switch circuit to coil since the switch is column located. Anybody have an illustration or digital image of what/where the ballast resistor is. Thanks!@

Check this post for diagrams:

ignition circuit

Seabronc is the expert on electrical stuff

The ballast resister is not a resistor on the Diraspark system. It is a resistive wire that is burried in the wiring harness. I wouldn't expect that this is your problem.

From what I understand, you can't get it to start without jumpering to the battery. the ballast resistor is not in the circuit with the key in the start position. If my assumption is correct, (you don't get 12V at the coil when the key is in the start position) there are several things that could be wrong. With the key held in the start position ( red lead off starter solinoid so starter wont turn over) probe the white lead on the ignition module located on the wheel well. If no 12V there, check the circuit shown in the attached diagram which goes back from the white lead to the ignition switch and on to the battery. Any one of the connections could be bad as well as the switch mounted on the lower column could be bad or out of adjustment.

If no 12V at the white lead, jump back to the large yellow lead to the switch, it should be hot at all times. If you get 12V at the yellow lead, check the( red/light blue) lead comming off the starter switch with the key held in start. If no 12V there then the column switch is bad or out of adjustment.

If 12V there, continue on, do you have standard or automatic? If standard there should be a wire with a jumper in it dangling near the column (red/light blue wire). If automatic, you could jumper it out and see if it starts, if so the switch on the tansmission is porobably bad.

Good luck,

>-

Last nights response wasn't too good. Sorry I was tired and the thought patterns wern't working well :blush: .

Let's try this again:

Does the starter turn over when you put the key switch in the start position? If so, then we know the circuit on the left of the diagram is good. Atleast to the start solinoid.

Do you have 12V at the coil + when the key switch is held in the start position?

(take the small red lead off the start solinoid to prevent the starter from turning over).

If the answer is No to both of the above, I would suspect the supply voltage to the ignition switch on the steering column or the switch itself. The supply voltage comes directly from the battery thru a fusable link, ( on the passenger side under the hood ), connected to a large yellow wire. If you don't have an amp meter it hooks directly to the left side of the solinoid. If you have an amp meter it is a little more complex and I'm including the diagram. The fusable links are all under the hood and on the passenger side. The two links on the right side of the diagram are burried in the wiring harness where it splits off the power for the blower motor on the wheel well.

If the answer to the first question is YES, and NO to the second, something is wrong in the lead from the ignition switch to the coil. Again the ignition switch could be bad or the circuit is open some place between the switch and the coil.

God luck,

>-

I have ignored the voltage supply connections to the ignition module since you said it will start and run if you jumper from the battery to the coil +. 12V is supplied via the white lead during start and the red lead in run. Jumpering in effect backfeeds these. That is also why I don't think the ballast is bad since it has to pass thru it to backfeed the red lead on the ignition module.

You are correct, [-X don't run long this way, because the ballast is bypassed.

The connectors C321 and C325 are the ones right by the ignition module.

Good luck,

>-

Thanks for all the great background and diagram's, Seabronc, you the man!

I'm looking at your page 18 start/ignition (duraspark) diagram. It looks like in key-start position, +12V comes directly to the +coil via wire 262 through 5216 through C325. What does the symbol at C325 mean, does that mean it's some sort of connection.

It looks like reduced voltage (<12V) comes in key-run via wire 16, through resistor wire to reduce voltage, then to 5216.

It seems to me that possibly wire 16(still not sure if it's a full resistor wire of an in series ballast resistor) is my source of problem, or connection C325. Do you agree?

I don't think the ignition switch is the problem beacuse the ignition module is still getting +12 through wire 20 at key-run(when I jumper +12V directly to coil truck runs fine)

I'll track back through system this weekend and try to figure these out and post result. Thanks for all help!

Oops, just caught your response that C321 and C325 are connectors by ignition module, thanks!

>- The ballast is a resistive wire. S216 is a junction point under the dash, close to the switch. The wire colors are also indicated on the diagram. From the start switch contact you have two wires, Brown with pink stripe and Red with light green stripe. Juncrion S216 is where the ballast wire connects. From there to the coil the wire is Red with light green stripe.

If you have 12V at the coil when the key is held in start, then yes, it most likely is in the connection of the (resistance wire) ballast. However, I would expect to have spark and attempt to start when the engine is turning over and then when you let go of the key it is like you turned it to the off position.

You can pull the connectors apart and use an ohm meter to see if you get a reading from C321 to C325, ( The White with light blue hash mark on C321 to Red with light green stripe on C325). With the connectors apart, the only path between them is the ballast resistive wire. If you don't get any reading, you are hot on the trail. Probable filures I can see are, the Ballast wire connections on either end, C325 connection ( located in an area with a high possibility of corrosion, I'd almost put my money on this area ), broken wire in start path, connection to ignition switch.

Good luck,

>-

Well, Seabronc, you nailed it. As it turned out connector C325 was in bad shape. Jumpered the red w/green stripe at that connection and she fired right up. /emoticons/[email protected] 2x" width="20" height="20" />

However, aother issue has presented itself. I wouldn't guess they're related, but odd to have another electrical problem at almost same time. Drove truck for a while and eventually battery died. I put another spare fresh battery in and checked voltage across battery before and during running and it's staying at about 12V. It's not jumping up to 14-14.5V when running, so first thought is alternator. I put in new alternator(after original supposedly tested bad at Advance Auto Parts) and no change?? The odds the replacement alternator is also bad have got to be pretty slim. I touched the battery output at the back of the alternator and it's reading 12V(when trucks running), what should this be?

I don't understand that alternator circuit very well, I've got 2 wires in back of alternator. 1 large one that runs directly to battery post on starter solenoid(I assuem this is the one that acts to recharge the battery?) and smaller one that runs from "FT" on back of alternator to "F" input into voltage regulator. Can you expand on function of these two wires, help!

OK.....I'm having almost exactly the same problem....but I had a few days of playing the shell game...where you try an find what she'll the pea is hidden under....after they shuffle them around

But some kept moving the pea..with my dome light shorted out...it threw all my test off... Goose chase...BUT THE ONE DIFFERENCE IS THAT....WHEN I RUN A JUMPER FROM a 12vlt lead...or the battery..to the coil.....it wont start....it shuts down the solenoid... Makes it click several times....then make anotherfunny noise....won't try that again don't want to burn somthing up....

OK, I don't see the diagrams that use to be attached to this subject, got lost in cyber space I guess.  So here are a few that may help you.

>-

Thank you these will come in handy