battery drain 1985

[surfboard]

I have a battery drain on my 1985 with all the fuses pulled.I have the FSM on PDF from Bishko and trying to trace it down on the hot at all times.The PDF copy of the power distribution leaves something to be desired .I have checked with the headlight disconnected at the hood which did not help.Does the isolation relay hot at all times?I know the power seat is hot at all times but can't see the others from the FSM.Is there a others that are hot at all times? I also did the alternator check and that was O.K. .

 

[air1jpg]

Did you also pull the fuses under the hood?

 

[Marv02]

I had a bad starter once do the same disconect it and see if that fixes it.

Have you disconected the battery and let it sit over night hook back up and see if turns the car over This will tell you if you have a bad cell in the Battery.

Are you sure it charging when it running.

 

[boomdriver]

I have a battery drain on my 1985 with all the fuses pulled.I have the FSM on PDF from Bishko and trying to trace it down on the hot at all times.The PDF copy of the power distribution leaves something to be desired .I have checked with the headlight disconnected at the hood which did not help.Does the isolation relay hot at all times?I know the power seat is hot at all times but can't see the others from the FSM.Is there a others that are hot at all times? I also did the alternator check and that was O.K. .

Your drawing is not detailing the whole elec system...

half your power pathways are NOT thru the fuse panel. They run off the jumper post thru fusable links under the battery then to destination...ECM, cabin assy, engine bay, chassis...all over the car.

D/C at the source, not the fuse panel.

 

[surfboard]

I am doing the draw test at the battery with a dvom. I pulled all the fuses at the fuse box first but still have the draw. I also disconnected the alternator.I was trying to see where all the always hot were and its the post you are talking about.The jumper post is what I'm looking for.Its that part of the Power Distribution schematic that is unclear.Is it behind the battery on the firewall?

 

[gmjunkie]

I am doing the draw test at the battery with a dvom. I pulled all the fuses at the fuse box first but still have the draw. I also disconnected the alternator.I was trying to see where all the always hot were and its the post you are talking about.The jumper post is what I'm looking for.Its that part of the Power Distribution schematic that is unclear.Is it behind the battery on the firewall?

Down low behind the battery,Between the Battery and A pillar!~!!

 

[WRECKER88]

Battery Drain

Get a test light and disconnect the negative battery cable. Now connect the test light to the negative terminal and the other end to the negative battery cable. If you have a draw the test light will be on. Start pulling fuses and disconnecting things until the light goes out. This is a easy way to find your problem.

 

[surfboard]

Thanks for your help on the location ! The FSM leaves alot of mysterys.

 

[surfboard]

:eyerole I took a look and couldn't find it.Does it look like a stud with a nut with wires to it? Also I did find a minor drain from the alternator only when I removed the two wire plug from the regulator with the battery A terminal still connected.Bad alternator too? its got a very minor 35ma draw but I don't think there should be any draw.

 

[boomdriver]

Your JUMPER POST is the small stud with orange and red wires bolted to it. Just follow the batterys POS wire to the post...easy. Then follow all the wires from there..thru the links to destination.

You have to remove the battery and support tray to access all the links. The jumper is supplied by a single wire that runs from the battery pos terminal.

 

[surfboard]

Thank you for the help.I'll have another look.

 

[surfboard]

Here is a link to a great Fluke meter PDF for electrical auto testing. assets.fluke.com/appnotes/automotive/beatbook.pdf. When I do the alternator test I get 35 ma.I guess there a problem.

 

[avp0713]

Battery drain 1985

I had a battery drain on my '85. Finally realized it was the "door open" button in the door jamb on the passenger side. While the door WAS closed, it would just not push the button in far enough to turn off the light. It is possible not to notice the 2 courtesy lights. I replaced the door jamb button to resolve the issue.

 

[surfboard]

Thanks for all the replys.My power distribution looks a little different but I can't read mine as well because certain areas because it's the PDF of a copy from Bishko of the Factory service manual.Mine is in Black and white.The color one would be a great help for wire tracing.My battery B+ for the alternator goes straight to the battery from the alternator. I think I might have a diode starting to go bad as I have a 35 ma draw from it.Not much but it's not supposed to be there.Plus I have a 18ma draw that stops when I disconnect one of the fusible links by the battery and will have to trace one out. I am going to have to go under a disconnect the hot leads at the starter like you said as I might have a minor draw there also looking at the diagram you posted which I appreciate you posting.Might have a minor draw from the soleniod which can happen.All these minor draws add up to alot more than the 35ma that the FSM allows so I think that what is draining the battery over 4-5 days sitting.

 

[boomdriver]

Don't the early cars have the power feeds direct off the starter Pos terminal?

I can't speak to which yrs or exactly when that might have changed, possible 85-86? I know my 87 has layers of protection between battery and fuses/ servos.

Battery has single cable to starter. No dist from there to anything else.

Red wire to jumper post where fusable link "A" then takes power to the fuse block...and a series of other 'tagged' hot wires go directly to other things, headlite doors, fans etc, underhood stuff.

The "A" wire from the jump splits (in harness) to lead to everything else...cabin, light switch, ign switch, fuse block, aux fuse block.

So, the fusable links can interrupt power to everything including the fuse panel...(which I did not know until now). I always assumed the fuse panel was on its own source, but its also downstream from a fusable link like everything else on the 87.

I know that I recently learned the value of clean jumper connections when I restacked the terminals on the post and failed to properly clean each. Car ran poorly,. misfired, alt voltage was low, poor over-all condition. Going back to the last place that was touched, I cleaned all the wire terminals on the post and reassembled and it was a different car. Even the alt runs about 1v more than it used to at all times. It used to dip below 12v with everything on at idle...no more. Idles at 14.7 after start-up...then settles to 13.9 to 14.3 with lites or other assy running...at idle. I gained about 1 volt by simply cleaning contacts.

Regarding the 35ma drain the OP sees at his alt, thats not alot but the alt CAn drain a battery if the diodes are blown. All it takes is ONE spark from a cross or a bad battery jump to do that. Then the alt turns into a drain for the batterys stored voltage. let it 'drip' long enough and its emply.

If the OP wants to see some improvement in his charging/starting system he has to do the work and take the battery and tray apart and inspect the links and clean the terminals. Next would be the ground bundles under the car.

 

[surfboard]

I haven't hit the jumper post yet but I'll let you know what I find.Again I appreciate every ones help with this.As far as power leads to the starter solenoid I'll look at that too.My power distribution diagram
in the area of the starter leaves a lot to be desired.can barely see one of the power branches from the battery + side which are twne side looks like a poor copy.I can see two points of power connection on one side an S202 and an S203 both with red wires.Maybe one of these are the power post.Will let you know.

 

[surfboard]

Here is another great link I found about battery drain.Testing battery and charging system

 

[surfboard]

I removed the battery tray and there isn't any power stud .There were no power wires to that area. Cleaned the ground lug with 2 terminals while under there. Looking again at the manual there are power feeds off the starter solenoid. Will check and clean them. with such a small draw reading on some internet posts about the draw dirty or corroded terminals can produce a small draw.

 

[boomdriver]

Well, if you do not have a small jumper post with about 5 terminals stacked on it, behind the battery near the door jam, then you have the system that Vetteoz detailed in the drawings he posted. I can;t be of much help there since mine is so different.

 

[surfboard]

I probable would have put the battery tray back on without cleaning the ground terminals if not for reading your post about good clean contacts.More than likely the contacts for battery power at the solenoid are dirty also.A valid point that bad connections can cause problems.I wouldn't step off the soap box yet!!