OK guys, im on my 3rd ignition module in 6 months, I have been told that this is not uncommon because some ignition modules go bad quick and some a bad when you buy it. My question is, do you all think that this is normal, and could there be somethiing else wrong with my jeep causing the modules to go bad????????????
Ignition Modules!!!!! UGH
- Thread starter xxjas12xx
- Start date
I have heard the same thing. I just bought one yesterday at autozone for $54 with a LLT. I might suggest that.
Are you having them tested at azone or some other part shop to see what is failing? I watched it yesterday go through 5 or 6 test. It failed one. At least if you see which one is failing you could compare to the next one that goes bad and see if it is consistant. Then try to track down what is causing it.
Almost forgot. I had him test my new one before I left the store. Had him do the old and the new 3 times each in a row to be doubly sure.
Are you having them tested at azone or some other part shop to see what is failing? I watched it yesterday go through 5 or 6 test. It failed one. At least if you see which one is failing you could compare to the next one that goes bad and see if it is consistant. Then try to track down what is causing it.
Almost forgot. I had him test my new one before I left the store. Had him do the old and the new 3 times each in a row to be doubly sure.
jay79cj7
New member
Grizzly wheels, stock suspension (pics)
What kind of jeep do you have? I have heard of this happening on CJ's and maybe YJ's when people unwittingly remove the ballast wire. I did it myself and fried my coil after I did the TFI upgrade. Check to see if you are getting a full 12 V at the coil/module or something lower. It should be lower from what I hear.
What kind of jeep do you have? I have heard of this happening on CJ's and maybe YJ's when people unwittingly remove the ballast wire. I did it myself and fried my coil after I did the TFI upgrade. Check to see if you are getting a full 12 V at the coil/module or something lower. It should be lower from what I hear.
jay79cj7
New member
The wire either coming to or from the coil (maybe both) should have some resistance to it. I think the voltage at the coil is supposed to be 9 V. I don't really know for certain because I tore mine out before I knew this. I ruined my coil, supposedly because of the higher voltage. Per some advice from Derff96963 I used some Radio Shack resistors to lessen the voltage at the coil. But I have only run the CJ for about 5 min total since I did this, and since it ran fine for several hours before it failed, I can't say that it was an effective fix yet. He said that he was blowing ignition modules before he put in the resistors and he is fine now. Check your voltage before worrying about this through.
derff96963
New member
Yes you did get that right. You are only supposed to have about 9 volts on the coil. It should have reisitance wire from the ignition switch to the coil. It looks just like normal wire so the only way to know is to get a Multimeter and check the voltage on the positive terminal of the coil. The other thing to check is make sure your module is grounded properly. If it is loose where it is mounted it could cause it to fry too. I had gone through three modules in like lest than a week until I put the resistors in. It had been a while now with no problems and the same module.
Yes you should only have 9 volts to the coil. If you do not have a resistor between the coil and the ignition module you are drawing to much current through the brain box and are causing a failure. Nothing against whoever said to get resistors from Radio Shack, but you should really get a ballast resistor from an auto parts store. They do not cost much and come with male spade ends. Also the resistors from Radio Shack are only maybe 1 watt as the ballast is at least 5 watts and will handle the constant current going to the coil.
jay79cj7
New member
The Radio Shack resistors he advised me to use were 20 watt, 8 ohms, low impedance. About 2 bucks apiece. I used 4 in parallel, so the effective resistance is 2 ohm. Got just the right voltage drop for the coil, and 4 x 20 watt should be plenty of dissipation. However, I am worried about how robust it will be to have these things under the hood taking the heat and vibrations. The good thing is with 4 in parallel, if one ages to destruction, there shouldn't be too much of a difference. Any advice on what model car/truck to get a ballast resistor from if I were to go that route long term?
Hi,
Jeep Cherokees (well the pre 1995 ones at least), use a ceramic ballast resistor to power the fuel pump through during normal operation. The resistor I believe outputs around 9 volts. They are found mounted to the wall of the engine compartment on the driver's side near the windshield wiper reservoir and air filter box. :mrgreen:
-Nick :!:
Jeep Cherokees (well the pre 1995 ones at least), use a ceramic ballast resistor to power the fuel pump through during normal operation. The resistor I believe outputs around 9 volts. They are found mounted to the wall of the engine compartment on the driver's side near the windshield wiper reservoir and air filter box. :mrgreen:
-Nick :!:
derff96963
New member
You mean Napa has a Ballast resistor for the 258. I looked everywhere but there when I had my problem and everyone said they don't make a Ballast resistor on a 258. I have first used 5 watt resistors from Radioshack and smoked them. I found the 20 Watt's times four should be more than plenty. As for the reliability those resistor are pretty strong. Pretty much as long an long as nothing hits them and breaks the ceramic they should be just fine. The only other Option you could do would be to get some resistance wire from a jeep dealer but I bet I don't want to know what they will probably want for it.
A ballast resistor is not used with motorcrap ignition. You have to buy one from another application. The Jeep used a resistor wire. It runs runs all over the Jeep between the brain box and coil. When you bypass this wire you need to install a ballast resistor to limit running voltge to around 9 volts. the main problem with ceramic resistors is they don't dissapate heat as well as a ballast resistor.
derff96963
New member
Just one Question. Aren't Ballast Resisots usually made of Ceramic. I work at Autozone and I have never seen a Ballast resistor that wasn't ceramic accept for the really small button style that go into the Dist. cap on some GM's. With the Setup I have, I have over 80 watts of disipation. There is no way that a normal Ballast resistor is more than that. I am not saying that one won't work for the coil. I am using mine slightly differently. I have them between the Coil and the Ignition Module. This Limits the current from the Module While still maintaining 12 V on the positive of the coil. Either way it prevents the excess current from being pulled through the coil.
I was not saying that ballast resistors were not ceramic, just that a ceramic style resistor doesn't have the surface area to disipate the heat like a ballast resistor does. If you have resistors wired in series between the ignition module and coil you do not have 12 volts at the coil. The resistors will cause a voltage drop before the coil. It does limit the current by raising the resistance in the coil curcuit.
Here is the reason for using a ballast and not a regular resistor.
ballast resistor: (BAL RES) A resistor constructed of a special type wire, the properties of which tend to increase or decrease the voltage in direct proportion to the heat of the wire.
This means that a ballast resistor will have little to no resistance when at startup. It will keep this low resistance until the current causes the heat to build up and cause resistance to increase the resistanceane then the resistance will decrase again as the current drops. This in effect will keep the brain box operating at max allowable current and not a constant lower current like regular resistors. They have used these since cars went to 12v and they must be doing something right.
Here is the reason for using a ballast and not a regular resistor.
ballast resistor: (BAL RES) A resistor constructed of a special type wire, the properties of which tend to increase or decrease the voltage in direct proportion to the heat of the wire.
This means that a ballast resistor will have little to no resistance when at startup. It will keep this low resistance until the current causes the heat to build up and cause resistance to increase the resistanceane then the resistance will decrase again as the current drops. This in effect will keep the brain box operating at max allowable current and not a constant lower current like regular resistors. They have used these since cars went to 12v and they must be doing something right.
derff96963
New member
Ok Fourtrial, I think we need to stop this. I am not going to say you are wrong and at the same time my way works too. There are more than one way to do anything. Why did chrysler use Ballast resistors and Ford Use Resistance wire? They both in essance do the same thing. They stop you from putting too much current through the coil. So lets just leave it at that.
Pic's of LED's installed
I was just trying to get as much info out there to help anyone that was having problems with their ignition. I myself have removed the ballast resistor from the ignition system of my jeep, points ignition. I don't mind changing points or replacing coils for the extra HP. It also will let you know if spark plugs are going to last. I have burnt them out in a matter of minutes.
Just trying to help.
I was just trying to get as much info out there to help anyone that was having problems with their ignition. I myself have removed the ballast resistor from the ignition system of my jeep, points ignition. I don't mind changing points or replacing coils for the extra HP. It also will let you know if spark plugs are going to last. I have burnt them out in a matter of minutes.
Just trying to help.
Similar threads
