Battery drains down overnight

Good afternoon.

If you disconnect the radio, does the drain drop to 50-75 milliamps?

Roy

Roy thanks for the quick response. I will try to disconnect the radio for I am not that limber any more to get the radio. I will let you know when I accomplish this task.
John

You are welcome.

Keep me updated.

Roy

I have looked into removing the multi wire connector going to the radio and see that the dash has to just about be removed. Can you suggest a way of getting to the 12 volt connector on the back of the radio in a more convenient way? Thanks for the advice.

Oh, while I have your attention what is the diode on the under the hood fuse block for?

Procedure for removal.

It is for the AC clutch.

Roy

REMOVAL PROCEDURE

CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices.

1. Disconnect the battery negative cable.
2. Remove the instrument panel accessory trim plate.
3. Remove the radio mounting screws.
4. Remove the radio.
5. Disconnect the electrical connector and the antenna lead.

INSTALLATION PROCEDURE
1. Connect the electrical connector and the antenna lead.
2. Install the radio.
3. Install the radio mounting screws.

Tighten
Tighten the screws to 1.9 N.m (17 lb in).

I guess I will put my cutting torch down and do it the way your recommend. Have a great weekend.

Kep me updated.

Roy

Roy, I surely will keep you updated to my solution. Right now I think I am going to replace the radio with an up to date one seeing this one is about 20 years old. I will see if the current drain problem is solved when I take the old radio out.I see so since in pulling the old radio for troubleshooting the problem without just going ahead and replacing it. If it is the problem it needs to be replaced and if it is not the problem it is replaced by being too old. Just like me.

I'll keep you informed of my findings. Thanks for the assistance.
John

You are welcome.

Always glad to help.

Roy

Roy, I should have realized about the diode for I have placed many Peak Inverse Voltage diodes in test equipment that uses small relays. We put them across the coil in reverse polarity and the eliminated the driver transistors being blown by the PIV generated by the relay coil. I had to replace several alternators in a 62 Plymouth Valient due to the diodes being blown out caused by an aftermarket air conditioning unit in the car. People did not think about this seeing this was the first car to use an alternator,
Thanks for the reply.
John

You are welcome.

Roy

Well here I am back again. I disconnected the radio as well as an aftermarket CD player and still have this 475 mil battery draw. Do you have any more suggestions? Any and all will help.

Did you remove all the fuses one by one? If you did, then it has to do with something not fuse controlled such as the alternator.

Roy

I removed each fuse one by one in the fuse compartment under the hood as well as inside of the car on the left side of the dashboard next to the instrument panel. When the fuse which controls the constant 12 volts to the radio and the instrument cluster this 470 mil amp drain goes away. I removed the connector going to the radio and the current draw is still there.I have replaced the alternator. When I replace the fuse the tachometer, speedometer and I think another gauge jumped. How and where is the control for these items? I am about to change the radio power to another fuse and put an on off switch in the existing power to the radio and just turn off this ckt when I park the vehicle. I have noticed several inquires about this same problem but do not see anyone answering with a solution to the problem.
Thank,
John

What did the draw drop to when you removed the fuse?

Roy

What was the fuse number so I can find out what is on that circuit?

Roy

It is fuse number 19 in the lower-left position of the fuse bank and is labeled as RDO/BATT and is 15 amps

Okay, again, what did the draw drop to with the fuse out?

Roy

This is a confusing question. With the fuse out there would be no current in the ckt. When I put my amp meter in that is acting like a fuse and completes the ckt. The amp meter then reads 470 mil draw. With the fuse in and the radio out there is still the 470 mil draw. The fuse is labeled RDO battery but there has to be something on the line beside the radio..

I attached the diagram of what is on the circuit.

Still waiting on an answer on the draw after the fuse is removed.

Roy

With the fuse removed there is no current flow in that leg. With the fuse in and the radio removed there is the 470 mil flow. This would indicate there is something in the instrument cluster drawing this phantom current. Stupid question, where is the control for the instrument cluster or do I have to remove the entire cluster? Right now the dashboard is open due to having removed the radio. I am thinking about just putting a switch in to control the power to the instrument cluster and putting the radio constant 12v on another ckt. What do you think?

Oh, what is "in left seat harn" at junction "s266"? I had not thought of this being the problem.
John

First, you check the draw at the battery with the negative cable removed. Insert the amp in line with the cable and battery. You do not check at the fuse.

You need to disconnect the components one at a time until the draw drops to 50-75 milliamps. If you disconnect it all and there is still a draw, then you have a wiring issue.

Roy

Roy, I have done all of that and narrowed it down to fuse 19 which feeds the RDO/Batt ckt. I have disconnected the radio and there was an aftermarket CD player on that ckt and I have disconnected that. This confuses me for the past 20 years everything has worked fine and then one mysterious night I had a dead battery. I replaced the battery and that did not solve the problem, then I replaced the alternator for this was causing the digital odometer and trip indicator along with the radio freq indicator and clock to have what I call a twinkling of the display. I had the same thing in a Caravan and replacing the alternator solved the twinking problem but the battery still drained overnight. I started investigating by removing the battery cable and check the ignition off state and saw the 470 mill current draw and by checking each fuse ckt I came down to fuse 19. Removing the radio and an associated CD player did not solve the problem. Now looking at the wiring diagram you sent, the only thing left is the hook up to the instrument cluster and "front seat harn". What is this front seat harn and can it be disconnected? I guess I will look under the seat and see if there is a connector. I know there must be a connector to a sensor that senses when the seat belt is engaged. and I will look for that.
John

The cluster and the HVAC controls are the other 2 on that circuit.

Where did you see this seat harness?

Roy

My bad, I was interpreting the diagram incorrectly. This might be a location definition for junction 266 showing all items are in the "left seat harness" where ever that might be. My climate control is the old fashoned knob adjust not electronic control. I have eliminated the radio so this leaves the instrument cluster. I would assume this has an electronic control for all and I guess this would be IN the instrument panel. I will look into how this is connected at least there is no flexible cable going up to the speedometer to disconnect.
John

Do not dismiss the control head for the AC. Disconnect that as well.

Roy

It is the label S266 in your diagram in the vertical line between the fuse and the instrument cluster. Oh, I will definately go and check the AC Control Head. Thanks,
John

Well the gremlin seems to have left my car overnight. I started to check the temperature control head and the stand by current draw has dropped to 70 mils. I went ahead and removed the connectors going to the temperature control panel one at a time and the current draw remained at 70 mils. I even disconnected the lights on this module and still 70 mils. Tonight I plan on leaving the fuses in as normal and see if the battery can sustain this 70 mil draw. This is a lot better than the 470 I started with. I will keep you posted but I really do not know what fixed the problem if it is fixed. Thanks for the assistance oh now to put my dash board back together.
John

Okay.

Roy

Roy, I thank you for your assistance with this problem. Well, I did some investigating and did not find the problem What I did was place a light bulb (back up bulb) in series e with the fuse. This was when current was being drawn it would light the bulb and alert me to that fact. The bulb was big enough to easily handle the ckt current draw. I also changed out the radio and the bulb comes on at about 1/4 brilliance. This I expected. Oh, when I first hooked up everything and the radio was not on the bulb would show a pulsating current draw. On for a second and off for a second. Before I inserted the bulb I had an amp meter in its place and it showed there was a 470 mil amp draw. Now with this jerry-rig where I can easily monitor the phantom current draw. I am going to leave this monitoring set up in place for a week or so and see if the phantom comes back to haunt me. I will let you know of any more happenings.
Have a Merry Christmas and a Happy New Year.

All in all I do not know what is causing the 470 mil current draw when all is turned off.

You are welcome

Keep me updated.

Roy

Roy,

It has been a month since I last communicated with you. Well, it looks like the instrument cluster was the problem. I got one from a large salvage company who goes by three initials and put it in the car. The phantom current draw went away along with the 470 mil amp pulse.Now only a few days will tell if this really solved my problem. Thanks for all of the help in solving this problem. Oh and to boot the instrument cluster came out of an S10 and it has the gear selection up on the cluster where my Jimmy SLS did not have this.

Well Roy, the sun is up on a new day and the old problem is still there. I tried to start old SUV this morning and the battery is almost dead and the SUV would not start. I will get back to trouble shooting the problem and let you know what I find.

Sounds good. Check the current draw again.

You may also have a bad battery.

Roy

I replaced the battery in November along with the alternator.

I would still check it to be sure. Do not dismiss it if the current draw is correct.

Roy