electrical alternator issues
Thread Starter
|
Junior User
Joined: Aug 2007
Posts: 73
Likes: 0
electrical alternator issues
Hay guys I have a brain twister, My batteries keep draining on my 1991 IDI 7.3 international. Some one told me if I disconected my battery cables the engine should stall out, meaning that the alternator is shoot and that is my issue.
So I did this and the engine kept running but my question is with a IDI diesel should it keep running regardless. ???
So I did this and the engine kept running but my question is with a IDI diesel should it keep running regardless. ???
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Have you had the batteries load tested?
In a semi dark place so you can see any small sparks, unhook both batteries from the positive cable.
As you unhook the last battery look for a small spark.
If you see one, or if the spark is not so small, start pulling fuses till it stops sparking.
the last fuse you pull is the problem circuit.
Also feel the alternator when the truck has not been running for several hours.
If the alternator is warm, the alternator is causing the problem.
I am not and never have been a fan of unhooking both batteries while the engine is running.
Some systems can be damaged that way.
Bad thing is, it don't really prove anything, it takes a very small amount of electricity to keep the fuel shut off solenoid open.
If the alternator was putting out about 1 amp at 6 volts, the engine would keep running.
But the truck would never start, and the lights would not work.
In a semi dark place so you can see any small sparks, unhook both batteries from the positive cable.
As you unhook the last battery look for a small spark.
If you see one, or if the spark is not so small, start pulling fuses till it stops sparking.
the last fuse you pull is the problem circuit.
Also feel the alternator when the truck has not been running for several hours.
If the alternator is warm, the alternator is causing the problem.
I am not and never have been a fan of unhooking both batteries while the engine is running.
Some systems can be damaged that way.
Bad thing is, it don't really prove anything, it takes a very small amount of electricity to keep the fuel shut off solenoid open.
If the alternator was putting out about 1 amp at 6 volts, the engine would keep running.
But the truck would never start, and the lights would not work.
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
The unhooking of the batteries only does one thing.... usually destroys the alternator. Those days you speak of were when we had generators........
As Dave stated do the fuse test..... but if you have a test light use it between the disconnected terminal and the battery..... if the fuses are removed/replaced one at a time as suggested with no effect, keep going until the light goes out. That is the offending circuit.
As Dave stated do the fuse test..... but if you have a test light use it between the disconnected terminal and the battery..... if the fuses are removed/replaced one at a time as suggested with no effect, keep going until the light goes out. That is the offending circuit.
Moderator
Joined: Jan 2001
Posts: 56,976
Likes: 2,733
From: Virginia
Here's how to hook up the testlight. Make sure you take one of the batteries loose though, since lots of people hook add-on equipment to both batteries. Speaking of which, you need to disconnect any wiring added to the batteries too, to see if the light will go out.
If all the extra wiring to the battery is disconnected, and none of the fuses makes the light go out, then I would disconnect the alternator and see if the light goes out.
If all the extra wiring to the battery is disconnected, and none of the fuses makes the light go out, then I would disconnect the alternator and see if the light goes out.
Trending Topics
Thread Starter
|
Junior User
Joined: Aug 2007
Posts: 73
Likes: 0
Ha HA I did it back wards, not surprising to me you should see some of the silly things Iv done whille learning about this engine.
thax the picture always helps. I have two batteries but I think there is no issues here with your picture.
thax the picture always helps. I have two batteries but I think there is no issues here with your picture.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
Junior User
Joined: Aug 2007
Posts: 73
Likes: 0
OK I ended up pulling both blacks, to which I asume each havin a groung to the engine bloke. I hooked up my AMP probe ,one leed to the battery post the other to the - cable or blackk as I call it. Right away I got 12 volts which I wondered if I was doing it properly , so I continued to pull the fuses and a 15 Amp fuse fot the interior step and drivers door caused the Amp to come down slightly. {the bus is not runnning} So I concluded that this waas the issue and at pressent just left the fuse out until I drive it a little longer, Can any one give any input to what I have do hear. Thax
Moderator
Joined: Jan 2001
Posts: 56,976
Likes: 2,733
From: Virginia
You should not be getting "12volts". If you are using an amprobe hooked in series like you described, you should be getting an amp reading. Using an amprobe, you have to determine what is good and what is a bad reading, since there is always a radio memory or something puttng a small drain on the battery. I would say if you are over 35ma, you are in trouble.
That's why the testlight works so well. It's a little crude, but the small normal drains you get won't light it up very bright.
That's why the testlight works so well. It's a little crude, but the small normal drains you get won't light it up very bright.
Thread Starter
|
Junior User
Joined: Aug 2007
Posts: 73
Likes: 0
yep, I'v been thinking about this not only was I using the Amp probe incorectly I had the drivers door open when I was pulling fuses to which would mean the inside light would be on and It only makes sence that the probe would move a little when I pulled it. I'll go buy a light today unless u know of a way u can make a home made one .
Moderator
Joined: Jan 2001
Posts: 56,976
Likes: 2,733
From: Virginia
If you have a small 12 volt light laying around, you can certainly hook it up and make a testlight. It may not have the fancy probe and alligator clip, but all you need are wires hooked to the bulb, and you can use it for the same purpose.
Thread Starter
|
Junior User
Joined: Aug 2007
Posts: 73
Likes: 0
I have some taillight bulbs Ill give it a try Thax
When I put my battery booster to the batteries this morning, it seemed that in fact the batteries did not drain over night but I'm still going to do the test light on it.
When I put my battery booster to the batteries this morning, it seemed that in fact the batteries did not drain over night but I'm still going to do the test light on it.
Elder User
Joined: Aug 2007
Posts: 728
Likes: 0
a 180 ma maximum draw is acceptible but thats for a luxury vehicle with all the bells and whistles , if the bus has an automatic electronic controlled tranmission the processor for it like the radio also has keep alive power so it has a continuous draw , the two most overlooked items are the under hood light and the glove box light either one can remain on and has a high draw
Senior User
Joined: Dec 2006
Posts: 344
Likes: 3
From: Byron New York
I have not seen it yet in the posts is your Altenator Charging? I just had one draining my batteries when the truck was shut off. The altenator was luke warm to the touch in the morning. It would charge when running but when I shut it off the next day I would be reprogramming my radio stations.
Changed the altenator it was back to working order batteries are only a year old. No problems since. Fingers crossed!
Changed the altenator it was back to working order batteries are only a year old. No problems since. Fingers crossed!