84 CJ7 258, now-- no click at solenoid, no crank. (Was hard start and engne cut out when warm)

When are you finding that 2.8 volts, with the engine running or with it off and the ignition switch on?

I'm trying to picture the wiring diagram and everything I've seen before has battery voltage, (lets say 14.0 volts) applied to the resistor, then current flows through it to the coil primary where the voltage will be lower, through the coil where we would like it to be real low, then through the module which takes the place of the breaker points. It's a switch.

If you're measuring that 2.8 volts right after the resistor where it connects to the coil, that may be fine. 2.8 volts across the coil doesn't sound like much, and not enough to build a nice magnetic field, but that isn't done with voltage. It's done with current. Doing the math, if you have 14.0 volts on one side of the resistor and 2.8 volts on the other, that's a drop of 11.2 volts. Using Ohm's Law, current equals voltage divided by resistance. 11.2 volts divided by 1.1 ohms equals 10.18 amps. That's a pile. Knowing the current we could also calculate the resistance of the coil and module but that is irrelevant. If that was a breaker point system the contacts would be red hot.

If you're measuring that 2.8 volts on the control side of the coil that connects to the module, not where the resistor is connected, we'd have to include the coil's resistance which is typically about 1 ohm or a little less. Lets say the resistor and coil together totaled 2.0 ohms. Current would be 11.2 volts divided by 2 ohms equals 5.6 amps. That's still a real lot but not quite as dramatic as before.

Next, you have to remember that if that 2.8 volts was measured with the engine running, the module turns the current flow off when it wants a spark to occur. That 0.0 amps gives the resistor, coil and module time to cool down until the module turns back on to build the magnetic field for the next spark. If that 2.8 volts was with the engine not running, the module is keeping the current flowing and it's waiting for a signal to turn the current off and make a spark. I could see 2.8 volts at the module but the 5 amps is a lot to expect from that sad little switching transistor in it. Current makes heat and transistors hate heat.

I wish I had the exact diagram to look at. Without one is like trying to drive cross-country with no road map.

I have my fingers crossed. Do you still have the same 2.8 volts with the engine running?

I'VE NEVER RUN INTO THAT ISSUE, I RECKON I SELDOM SEE A FACTORY TACH, AND NEVER ONE MESSED UP CAUSING THIS

......BUT I DID VERIFY THE SITUATION WITH A FACTORY MANUAL

OK HERE'S THE DEAL---MORRIS 4X4 HAS SQUARED US AWAY...........I HAVE THE PAPER ONE FOR A '79. JUST TO KEEP "ME" IN DEMAND, I USUALLY SHARE THIS INFO AS A GOING AWAY PRESENT TO ANOTHER JEEP GUY

https://www.2carpros.com/articles/mitchell1eautorepair-car-repair-manuals

I HOPE THIS MIGHT HELP YOU.....IT SURELY WILL AID ME

THE MEDIC

I will be very happy if this solves the problem but I'm going to throw a clinker in the works. Actually, it's just to realign your thinking to avoid some confusion. Early '70s Fords also ran the tach in series with the ignition coil. You have that right but it is not triggered from the positive coil terminal. That is the logical assumption since one of the tach wires goes to it, but you will find steady battery voltage there, as it should be, not voltage pulses. The clinker is the tach is not triggering off voltage pulses like aftermarket add-on units do. It's triggering off voltage pulses that RESULT from the current pulses through that circuit. The ignition coil primary current flows through the primary side of a small transformer inside the tach. Its resistance is so low it acts like another ignition resistor so for all practical purposes it's not even there as far as the ignition coil and module are concerned. Still, when the module is turned on and current is flowing through the primary winding in that transformer, the current pulse generates a voltage pulse in the secondary winding just like in any transformer for a cordless phone charger and stuff like that. THAT'S the voltage pulses the tach triggers on. Since it is indeed wired in series with the ignition coil, it could just as easily be placed between the coil's negative terminal and the ignition module and it would work just as well.

There's two reasons to have the tach come first in the circuit. One is that the 12 volts coming from the ignition switch is already right in that same area so only one wire has to run through the firewall to the coil instead of two wires. Second, people who know how tachs work could be confused if they found it tied to the negative coil terminal. They would incorrectly assume the other tach wire was supposed to go to ground like the aftermarket units do. When they see it tied to the positive side that they know has steady battery voltage, they will figure out this is wired differently and works differently.

My cousin had a '73 Mustang, (currently owned by Jamie McMurray's pit crew chief), that had this problem. Being a tv repairman like me, he unwound that transformer and rewound it with new wire. That solved his intermittent no-start problems. After all these years I would be more inclined to suspect bad solder connections on the terminals of your transformer or corroded plug-in terminals.

GOOD DEAL!

I'VE NEVER COME ACROSS AN INTERMITTENT FUSIBLE LINK. EITHER THEY WORKED OR THEY WERE DEAD. GENERALLY WITH A BAD ONE, THE INSULATION LOOKS "BUBBLED" OR IF YOU TUG ON IT, THE INSULATION STRETCHES OUT LIKE A RUBBER BAND

I RECKON I'LL SLING THAT INFO OUT NEXT TIME.I DO HAVE A POST WITH PICS, WHERE I EXPLAIN THE FUSIBLE LINKS

MAKE SURE YOU REPLACE IT WITH THE SAME/ CORRECT LINK

THE MEDIC

CJ can you please! Send me the exact location of the ( Crankshaft Position Sensor ) on a 1996 Hyundia Accent SOHC 1.5 liter. I goggle it but nothing seems to come up thank you my friend

Send it in here or catafina the user-thank you again

You need to start a new question specific to your car. This question relates to a Jeep.

Unlike other sites where anyone can post a reply, here it becomes a private conversation between you and one or two experts. This shows up on our list of questions that have received replies already. As such, the other experts won't butt in or read your addition, so they won't have a chance to reply. That won't get you the help you need.

When you post your question, be sure to state why you want to find a part. Way too often people are going after a part that can't possibly cause the problem they're trying to solve, and we can make better suggestions based on the symptoms. Also, please be sure to list the engine size, mileage, and transmission type. We need the engine size to find the right wiring diagrams and when looking up parts locations. We use the mileage when making judgments as to the best suspects.