Help!!!!

[D69charger]

After driving the car for a short time... the positive and negative cables at the battery are hot to the touch.  I don't know where to start looking for the problem

[ottawamerc]

I would guess at a dead battery and it's drawing to many amps (shorted inside) or voltage reg? What does your gauge say?

Scott

[D69charger]

no the battery is not dead.  It will still start the car.  and the ammeter gauge inside the car doesn't really move.  it has drained the last battery in the car which is why I was pulling the battery cables off after I did a short drive.  The cables were pretty hot to the touch.

[Pete in NH]

Hi,

It sounds like you have a serious short circuit somewhere. I would leave the negative battery cable disconnected until you can track the problem down.

Do you have any type of a electrical test meter you can use to find the problem? Also, have there been any recent changes made to the electrical system in the car? These are fairly simple electrical systems and with a little simple trouble shooting I think the problem can be found. I can step you through the trouble shooting if you would like.

[D69charger]

both battery cables are disconnected.  After the motor rebuild I added a march serpatine conversion with a alt that is 1 wire setup.  I have electric fans for the rad.  They seem to work fine and only come on at the temp setting they are set for.  I have car stereo but have the positive cable for it disconnected as well.  there is a ground coming from the battery to the inner fender and to the motor. 

On the short drive I did yesterday it seemed like my stock gauges were not working properly.  Temp gauge seemed to be reading higher than it really was and oil pressure gauge was reading lower than I know the motor did on the dyno.  I also have a rad cap that has a built in temp gauge and it showed the temp at 180 while the gauge in the car was reading 220+.  after knowing of one battery that has been killed by this car... I went to remove the cables after my drive and they cables were pretty hot to the touch.  im figuring that I have a bad ground somewhere?  or maybe something with the dash gauges is the problem?  I am planning on getting mechanical gauges for temp and oil pressure and rely on those readings over the stock gauges.  but that doesn't explain why my battery cables are getting hot.  im confused on everything with this car.

[Pete in NH]

Okay, things are not quite the way the car left the factory. When you say the battery cables are getting hot, how warm are they getting? After running the engine a while everything under the hood will get warm. You can hold onto something around 140 degrees F after that you will pull your hand away. Are the cables warmer than that?

One simple test would be to reconnect the positive battery cable and make sure everything in the car is turned off, including closing the doors so the dome light isn't on. Then lightly touch the negative cable to the negative battery terminal. If you see a spark something is drawing current. It helps if you do this in a slightly darkened area.

Also, tell me more about that one wire alternator. How many amps is it and where is that one output wire connected?

With a factory electrical system we know it all worked at one time. With modifications we don't know if it ever worked correctly. So, since I can't be there in person to look things over, I'll have to ask a lot of questions to understand what is in the car. I might also ask for some pictures to help understand. But, we should be able to get things sorted out.

[D69charger]

well I can tell you with the test you want me to do that there is definitely a spark.  A while back with my old battery in the car I had the hood up as I was trying to start it and got a huge spark from the negative cable and then the whole car was dead.

the alt is a GM 160 amp I believe.  I will have to follow the wire to see where it is connected... I didn't install it.

[Pete in NH]

A 160 amp alternator is way too much current for the stock car wiring system to handle safely. So, the next step is to know where the alternator output wire is connected.

[D69charger]

im only guessing at 160... it might be a 120 one.... its a GM chrome alt

[Pete in NH]

120 amps is still about three times the current of the original alternator. We still need to know where the output wire from that big alternator is going. If it is going to the original dash wiring the ammeter is going to fry if something goes wrong.

[D69charger]

ill figure out tomorrow where it goes.  I have poor lighting in my garage and need a treble light. 

[c00nhunterjoe]

 Big alternator- electric fans- stock bulk head connector rated for 40 amps....... check for melted power wire at the bulkhead. And if your ammeter is not bypassed; bypass it before your car goes up in flames.

[D69charger]

how do you bypass the ammeter?  I for sure don't want to start a fire

[myk]

how do you bypass the ammeter?  I for sure don't want to start a fire

There're two wires connected to the back of the ammeter.  The "backyard" mechanic method of bypassing the ammeter is to join these two wires together with a machine screw, nut and wrap it up as best as possible with electrical tape, or something.  Anything more powerful than the stock 'alt with the ammeter connected and running 50 year old factory wiring is a fire waiting to happen.  Do the ammeter bypass, and then run a heavy gauge wire from the output stud on the 'alt to the starter relay...

[Pete in NH]

What most people who make changes to these cars by adding big alternators and electric fans don't understand is the electrical systems in these cars were never designed to deal with the higher currents involved. To handle the big alternator and electric fans considerable changes need to be made to the electrical system.

Again, the first thing I need to know is where that alternator output wire in connected.

I also sense that you are  new to these cars and like many people new to electrical systems. There are people here on this board that can help you with what needs to be done. But, if you need to make changes in the wiring do you know someone who is more familiar wire automotive wiring that can help you make the changes?

[D69charger]

ill trace down where the alt is connected tomorrow.  Work was super busy today and I didn't get to it.  And yes I have a few friends that can handle the wiring side for me.

[D69charger]

it looks like the wire from alt is running to starter relay on firewall.  I had a friend over tonight and we checked out everything we could wiring related on the car.  There is a 3 amp draw somewhere on the system.  Taking the fuses out did not affect anything. We took one out at a time to see if anything on the mulitmeter would change on the output.  also the car has a alarm system that is not functioning at all.  Disconnected the power wire to the brain of the alarm box.  None of this did anything to stop the draw.  We then moved to taking one wire at a time off the positive cable of the battery seeing if we could pin point where the draw was coming from.  Again nothing happened.

With the car running the ammeter needle is leaning slightly to the right.  don't know if this means nothing or not.  I am getting seriously confused on where to look next.

[Pete in NH]

The alternator output going directly to the battery stud in the starter relay is the right way to hook up that big alternator. That will bypass the ammeter so that it will not indicate charging current.

The procedure you followed of removing one fuse or one wire at a time was a good one and what I would have recommended you do. So, at his point I'm a bit puzzled  as to what is happening here. The only other thing I can think of right now, is that the alternator may be in trouble and always drawing field current. With those one wire alternators the regulator is built into the alternator and gets its field current from the battery all the time. With an external voltage regulator system the field current is turned off with the ignition key. Try disconnecting the alternator output wire from the starter relay stud and see if the 3 amp draw goes away.

[D69charger]

so if the alt going to starter relay bypasses the ammeter... then how come the ammeter gauge is still working?

[Pete in NH]

With out seeing the wiring in your car I can only guess why the ammeter still reads something. My guess would be that someone left the original ammeter wiring in place and ran the alternator output to both it and a new wire from the alternator output to the starter relay stud. This would from a parallel path that would allow the ammeter to read full discharge current but only some small fraction of the actual charge current. As I said, this is only a guess without seeing the car's wiring. If it is wired this way there is a potential issue about adequate protection and fusing of both these paths.

On the 3 amp draw, I would look at the alternator fields current issue and then look for a trunk or glove compartment light that is on all the time. I would think pulling the fuses would have found that problem , so take a careful look at the alternator.

[D69charger]

I pulled the wires off the alternator and it didn't affect the draw on the multimeter.  Still haven't found the draw and its driving me insane.  The car seems fine when driving... just have to take the ground wire off the battery at night so the battery isn't completely drained the next time I want to go out.

[Cooter]

... just have to take the ground wire off the battery at night so the battery isn't completely drained the next time I want to go out.

If you've ever watched one of these cars burn to the ground, this ain't a bad idea.
I've been doing this very thing for the last 20 years.

[Troy]

... just have to take the ground wire off the battery at night so the battery isn't completely drained the next time I want to go out.

If you've ever watched one of these cars burn to the ground, this ain't a bad idea.
I've been doing this very thing for the last 20 years.

I never walk out of my garage with batteries connected in any of the old cars - and most have all new wiring! I also usually plug them in to a Battery Tender so that helps me to remember to disconnect them. My garage is NOT where I live so I don't want anything happening that I won't be aware of for hours or even days.

Troy

[suburbanfireman]

Is it possible that the battery has an internal short?  Older batteries have a series of vertical plates allowing the acid to flow between them - could one of the plates fallen over and is now touching another plate?  Disregard if you have a dry-cell battery.  I'm just throwing out an idea.......

[D69charger]

Is it possible that the battery has an internal short?  Older batteries have a series of vertical plates allowing the acid to flow between them - could one of the plates fallen over and is now touching another plate?  Disregard if you have a dry-cell battery.  I'm just throwing out an idea.......

no it has been doing this with a red optima in the car at first and now it has a new interstate battery in it.