88 FJ62 Battery Drain

[php74]

This is going to be very vague, but my battery drains when the vehicle is off. The battery is new and the alternator is working because after I jump it and then drive it, it will start up again. Then when it sits for a couple of hours it is dead. Is there any common cause in these vehicles? Thanks.

 

[Texx]

Lots of times it's an alarm system, either current or left over from a previous owner. Have the new battery checked for a dead cell.

 

[bigbertha]

regulator

You might also check your voltage regulator. I had the same problem in the 60 and thought the alt was shot. After breaking out the FSM, I tracked it down to the IC regulator. No brainer fix. All is well.

 

[php74]

Thanks a lot, I will check those out. I appreciate it.

 

[Wile E Coyote]

After you find out that those weren't the problem, try this......
Pull the radio and FI fuses, close all doors, turn off all accessories, etc. Remove the NEG battery cable and let it lay loose. Place a multimeter, set on amps, and connect between the still connected POS terminal, and the LOOSE CLAMP, NOT battery post, but the loose CLAMP, and read the current load.
Do not read current (AMPS) from pos to neg on the battery terminals with your run-o-the-mill meter. It will immediately fry.
You still may get up to 0.5 amp load, but anything higher than that, (With ALL accessory loads removed as described) means you have a short somewhere. Give the meter a break to cool ( only read load for 10 secs at a time every few mins) and then start the real fun.
Get a buddy to make things quicker. Start pulling fuses and CB's one at a time, watching for the meter to fall to zero. When it does, that's the curcuit that's causing the drain, and the one you should focus your attention to. It may feed the iggy, the radio, the int. lights, or a dozen other curcuits, but at least you'll have narrowed it way down. If all the fuses and CB's are pulled, and the drain remains, then it's on a curcuit directly to the battery and bypassing the fuse panel. Added any relays, lately?
Sounds fun, huh?

 

[SmallManBigMouth]

Wile E,

Great advice. Do you think I might be able to diagnose the source of the problem that causes my two rear door locks to not operate using the same method you outlined? I'm pretty sure it's an electrical issue as I've taken both door panels apart to clean and lube everything. It's been suggested that it's a resistance issue, but I haven't been able to determine the source.

Thanks,


s.

 

[Wile E Coyote]

No, you would use it to narrow all the other possibilities of a SHORT to the rear door lock circuit. Then you would be able to focus your efforts on that particular circuit.
In your case, you already know the offending circuit.
What are your symptoms, and what have you done so far to correct them?

 

[loeky]

After you find out that those weren't the problem, try this......
Pull the radio and FI fuses, close all doors, turn off all accessories, etc. Remove the NEG battery cable and let it lay loose. Place a multimeter, set on amps, and connect between the still connected POS terminal, and the LOOSE CLAMP, NOT battery post, but the loose CLAMP, and read the current load.
Do not read current (AMPS) from pos to neg on the battery terminals with your run-o-the-mill meter. It will immediately fry.
You still may get up to 0.5 amp load, but anything higher than that, (With ALL accessory loads removed as described) means you have a short somewhere. Give the meter a break to cool ( only read load for 10 secs at a time every few mins) and then start the real fun.
Get a buddy to make things quicker. Start pulling fuses and CB's one at a time, watching for the meter to fall to zero. When it does, that's the curcuit that's causing the drain, and the one you should focus your attention to. It may feed the iggy, the radio, the int. lights, or a dozen other curcuits, but at least you'll have narrowed it way down. If all the fuses and CB's are pulled, and the drain remains, then it's on a curcuit directly to the battery and bypassing the fuse panel. Added any relays, lately?
Sounds fun, huh?

this is awesome info for everyone on the board - we should post this in the sticky. i'm gonna PM Mike and ask.

 

[Wile E Coyote]

Nah, just follow this link to the 'bible' for many things automotive electric:
http://www.madelectrical.com/

 

[SmallManBigMouth]

Wile E.,

Thanks. Mad Electric has great info.

The symptoms of my rear door locks are basically that at resting charge (engine not running) they don't actuate up or down. I can hear the locks and actuators attempting to work and if I give them "help" by pulling or pressing a bit, they'll work. At full charge(engine running above 2500rpms) they work great, but that's of little help to me when I'm trying to lock the doors at night when I get home. I've taken the door panels off and looked at the guts and everything is clean and lubricated.

Any ideas would be great appreciated!

 

[Wile E Coyote]

This only affects the rear locks? No headlight/dashlight brightness, or wiper speed varying with rpm's? Nothing else? That's an interesting one.
Well, I'd help ya out if you were a Fugazi fan, but a Minor Threat fan?

 

[swampymarsh]

I have had a simmular condition on my 88 FJ as well. Went out to start it after I got home late the night before and the battery was dead. Charged it up and drove it and the next day it wouldn't crank again . The battery was getting old so I thought that I'd replace it. Put the new one in and the Volt meter was going from 14volts to 8 volts and back. Heard a clicking noise at the same time. What has happened is the RR door switch was stuck on, and it was the thermo overload switch poping on and off. Any way fixed the switch and the problem was solved.

Don't know if this will help but it was an unusual condition......

Dave

 

[SmallManBigMouth]

Come on Wile E.,

Don't leave me sitting here IN THE WAITING ROOM. I might start SEEING RED.

Yah, my door lock issue doesn't seem to affect the wipers, headlights, etc. But, the windows are a little slow with the engine off. Import Silvia posted at one point that he improved the harness for the door locks and windows on his 62 by disassembling the whole harness and soldering all the crimp connections. I guess that'll be my next best bet, but it sounds like a PITA. So, I thought if any one had advice...

 

[Wile E Coyote]

High resistance is the best explanation thus far. raising the resistance( think WAy higher than norms) will up the amps delivered through the circuit, but drop the volts. Our 12v systems actually perfer around to 14v to operate a peak, so if the rear locks are getting 8 v (big guess there), that might cause them to not work at idle. Working only after revving the rpms up, well that fits right into our little explanation nicely.
Lets compare voltage readings: 1st, check batt voltage at idle. Pull those rear panels off AGAIN, and check voltage directly at the motor connections, then check at the circuit breaker (under the dash, hanging by itself amongst the other wires behing the fuse panel area).
If I'm right, you'll see a big drop from batt voltage to circuit voltage.

Edit: Try at the CB after the batt voltage check, if it's low there, it'll save pulling the rear doors apart, since the problem wouldn't be in the motors, but before.
I'll be sitting here, the pivot man in this Circle Jerk, waiting for your results.

 

[Wile E Coyote]

After rereading your latest post.........If crimp connectors are whats at the motors, then I'll bet dollars-to-donuts that's the problem. Crimp connectors are evil things, and dont belong on a car. 12v systems are too sensitive to voltage drops for them. ( bad connections cause high resistance, and well, you've already heard about that.)

 

[SmallManBigMouth]

Thanks again Wile E,

I'm off to get a voltmeter...(that'd be a good start, right)

I'll let you know what I find out tomorrow. No need to wait on LOCKDOWN, but thanks for the SUGGESTION.

 

[jmarsh1977]

If you isolate a circuit going to the battery itself...check the fusible link on the positive cable. A cheap part from Toyota and it solved my battery draw down.

 

[SmallManBigMouth]

Wile E. and Marsh,

Definitely not a fusible link issue. That was the first thing I thought of and promptly ordered a new set from CruiserDan.

So, got the voltmeter and went to work... At the circuit I'm getting a reading of 11.7-11.9. I pulled the panel off the rear driver's side door and measured there with a reading of 5.6-5.9 with the engine off, and 7.7-7.9 running at idle. So, something along the path is killing voltage. I may have some time tomorrow to work on it. I guess it'll probably involve pulling the door harness totally apart and checking/repairing connections and soldering. I suppose I know what I'm in for, but any advice, as usual, is appreciated and helpful.

Thanks.

 

[Ming89FJ62]

The only things inside the rear door are the window motor and the solenoid for the door locks - both controlled from the master switch on the drivers door. You might want to check the master switch for a stuck contact.

Harry

 

[baldredhead]

After you find out that those weren't the problem, try this......
Pull the radio and FI fuses, close all doors, turn off all accessories, etc. Remove the NEG battery cable and let it lay loose. Place a multimeter, set on amps, and connect between the still connected POS terminal, and the LOOSE CLAMP, NOT battery post, but the loose CLAMP, and read the current load.
Do not read current (AMPS) from pos to neg on the battery terminals with your run-o-the-mill meter. It will immediately fry.
You still may get up to 0.5 amp load, but anything higher than that, (With ALL accessory loads removed as described) means you have a short somewhere. Give the meter a break to cool ( only read load for 10 secs at a time every few mins) and then start the real fun.
Get a buddy to make things quicker. Start pulling fuses and CB's one at a time, watching for the meter to fall to zero. When it does, that's the curcuit that's causing the drain, and the one you should focus your attention to. It may feed the iggy, the radio, the int. lights, or a dozen other curcuits, but at least you'll have narrowed it way down. If all the fuses and CB's are pulled, and the drain remains, then it's on a curcuit directly to the battery and bypassing the fuse panel. Added any relays, lately?
Sounds fun, huh?

are you sure the multi meter doesn't go between the negative terminal and the negative clamp that is disconnected? connecting the negative lead to the positive terminal through the meter won't produce a voltage difference right?