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Electrical woes

2K views 12 replies 5 participants last post by  JeepHammer 
#1 ·
So I am tooling down the road thinking " Man! My new (old) CJ rocks!" and I get to work, park the beast, shut her down feeling everything was right in the world. I jump back in the Jeep (it had been raining all day) try to fire her up and she is deader than dead. I try to jump it and nothin'..I put a new battery in and as soon as I connect the positive cable POOF! the fuse wire between the solonoid(sp?) and alternator blows. Crap..:brickwall

I had this happen many years back with a different vehicle and it was a faulty solinoid. I replaced it and POOF! Now I'm tapped...My mechanical abilities are pretty low but I do take direction well. Could it be the volt regulator in the alternator that is bad (the alternator is a AZ Duralst). I bypassed the alternator to see if I could get it to turn over and it did but no spark..

Any ideas for this clueless but well meaning CJ owner?

Thanks,

Chris
 
#4 ·
Sorry, I didn't read your whole post very well. The solinoid could be bad or a bad ground is very common. The solinoid is grounded by the screws into the fender. Make sure those are claen. Dirty connection at the battery cables is another place to look. The alternator is grounded using the alt bracket. Sometimes this rusts. You can run a dedicated ground from the alt to the neg. battery. Also make sure that the ground from the battery to the engine has a clean connection.
 
#5 ·
You don't say what flavor of Jeep, but...

When the alternator shorts out it can kill the battery dead.

When you hooked it back up, it blew the fuse link, it also likely blew the fuse link to the ignition or the fuse to the ignition. My 86 alternator excite is factory tagged to the ignition power so a short can blow lots of things.

A multimeter will tell you if you have power to the coil when the key goes to 'run'.
 
#6 ·
Thanks much Mike,

I did indeed find that the ignition fuse was blown. I took the alternator off and took it to one of the local parts stores to see if was still good--that was a disappointing experience to say the least. They said it was fine but also said they coukldn't tell if it had a short..what kind of answer is that?? I am way to new at the mechanics game but I figure a diagnostics machine would do exactly that--diagose. Ah well, I will order a new alternator tomorrow and see what happens.
I replaced the solonoid, battery, fuses, cleaned the mount screws, battery cables, and checked for bare wires. I am really hoping it is the alternator. I didnt forget your tip about the multimeter its just that..er..well, I am reading up on how to use one.

Thanks again for all the help,

Chris (BTW-its a 84 CJ 7 w/ a 258)
 
#7 ·
Ok, thowing the towel here. Replaced the battery, solenoid, numerous fuses, and now the alternator. All that and the fuse link between the alternator and solenoid is still popping whenever I hook up the battery..Grrr. I'm sure it a stupid loose wire making contact where it shouldn't but I cannot find it to save my life. Any last pieces of advice before I tow it down to the local wrench?
 
#8 ·
OK, the only other things on that circuit are the coil and ignition module.

I would put an inline fuse holder in in place of the fuse link and try it with the ignition module unplugged and then with the coil unplugged.

Maybe even start with the coil or check it's resistance. They do short out.

The meter should be set on resistance or ohms. You then check from the positive post to the negative post on the coil and the reading should be 1.13 to 1.23 ohms when cold. Then you check the center spark wire socket to the negative. That should be 7700-9300 ohms cold.

The pickup on the distributor could also short. The resistance between the orange and purple wires going into the distributor should be between 400-600 ohms.
 
#9 ·
I read Mike-from-the-North's advice and went out to the CJ, took off all the wires, put them back on, hooked up the new in line fuse holder (30amp), then hook up the battery terminals--cringing all the while. No poofs, no tell tale smoke! I kept my fingers crossed and turned the key--it cranked right over..(sigh) It was a moment to savor.
Now the down side..I let it run for about a minute when I saw the voltmeter drop. I checked under the hood and the fuse blew. The beast turns over and starts great now (thanks a million Mike) but that gremlin is still lurking in there somewhere..
 
#11 ·
I would take a wild guess and figure a 60 amp alternator would put out 60 amps under full load. ;-) I think mine does 65A.

That blown fuse might not not be an issue at all. You can get larger fuses or maybe put two 30's in parallel (side by side) for testing.

Some new vehicles actually use a large fuse instead of the fuse link wires.
 
#13 ·
I get to work, park the beast, shut her down feeling everything was right in the world. I jump back in the Jeep (it had been raining all day) try to fire her up and she is deader than dead. I try to jump it and nothin'..
Was the battery dead, or did you have a bad connection or starter solenoid?
Did the solenoid 'click' or was there NO noise when you tried the key?

It's the no crank with jumper battery.
A completely discharged battery won't jump start, but the second battery (jump battery) should have made the starter relay/solenoid 'Click' when you hit the key...

If you have REALLY bad battery connections, and you hook jumper cables to the, "Not making connection" clamps, then the second battery is not making any more connection than the vehicle's battery was...

I put a new battery in and as soon as I connect the positive cable POOF! the fuse wire between the solonoid(sp?) and alternator blows. Crap..
Probably a starter relay, often called a solenoid... Mounted on the fender right in front of the battery...

Anyway, if the fusible link to the alternator popped, you probably have a grounded primary wire to the alternator.
This could easily kill your battery while at work, and fry when you clean the terminals and attach a second, fully charged battery to the grounded circuit.

Fusible links don't pop for no reason, something is seriously wrong with the primary alternator wire or in the alternator it's self...

I had this happen many years back with a different vehicle and it was a faulty solinoid.
Starter relay/solenoids are the 'Restriction' in the starting circuit, and cheap discount store solenoids cause even more problems.
If a starter relay/solenoid welds shut, and they do with amazing regularity, certain components can be energized even after you turn the vehicle off, and drain the battery...

That doesn't explain the fusible link to the alternator burning...
That fusible link has one job, protect that primary charging wire to the alternator, and has NOTHING to do with the starter relay/solenoid other than hooking up to the battery cable at one of the terminals...

I replaced it and POOF!
Replace 'IT' what?
The Fusible link, the starter relay/solenoid, the primary charging wire to the alternator, the battery?...

What are you referring to you changed and it went 'Poof' again?

Now I'm tapped...My mechanical abilities are pretty low but I do take direction well. Could it be the volt regulator in the alternator that is bad (the alternator is a AZ Duralst). I bypassed the alternator to see if I could get it to turn over and it did but no spark..
The 'Voltage Regulator' in the alternator pretty much means it's a Delco SI series that is internally regulated...

That means it CAN NOT be the voltage regulator...
Might be the AC to DC Rectifier in the alternator, but not the voltage regulator...

Any ideas for this clueless but well meaning CJ owner?
Yup.

First things first,

Disconnect the alternator large wire, the Primary charging wire that had the fusible link in it.
DO NOT hook that wire back up until you replace the fusible link!
A fuse is ABSOLUTELY MANDATORY!

Second, Remove the coil wire from the ignition coil,
Take a spark plug and wrap a stripped wire around the threads, and connect the other end of that wire to the battery negative terminal.

Have someone crank the engine and watch the plug for spark...

IF, you have spark, the ignition is working, hook the coil wire back up and remove the test plug.

IF, the test plug doesn't spark, you need to get a test light and check the negative terminal on the coil during cranking.
If the light flashes, the module is switching the coil, and you may have a coil problem.

IF, The test light doesn't flash, try looking for voltage at the positive terminal of the coil with the ignition 'On'.

IF, you do find voltage, it's probably the ignition module.
IF, you don't find voltage, it's probably the ignition fuse under the dash.

Look for the small terminals on the starter relay/solenoid.
One will have a blue wire and be marked 'S'.
This terminal should be 'Cold' (no voltage).
The blue wire should only have voltage when the key is in the 'Crank' or 'Start' position.

The other small terminal should have an 'I' and a red wire.
This terminal should be 'Cold' (no voltage) unless the starter is turning.
The red wire will have reduced voltage when the key is in the 'Run' position.

The starter cable terminal will be 'Hot' (battery voltage).
The Starter terminal should be Cold (no voltage) when the solenoid is at rest.
The only time the starter terminal should have voltage of any kind is when the starer is turning.

The best way to test your alternator is to take it off and have it bench tested...
Since it's free, have it tested at two or three places and get a consensus on it's suitability to be reused...
I've found that often the kids at the parts stores don't know how to work the testing machines, so have it tested in a few of the chain stores and that should tell the tale.

Do you need a wiring diagram of your starting/charging system?
 
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