Parasitic draw before fuse block. (1 Viewer)

[SteadiCruiser]

I'm getting a significant 11 amp parasitic draw from the battery.

I've narrowed it to the single positive line heading from the battery towards the fuse block, but it seems to be happening before the fuse block.

What might be the most likely culprit?

Ignition switch?

I did reinstall the instrument cluster recently and ignition switch /column during the restoration.

Amp meter shorting or touching something behind the panel?

Thanks for any pointers.

 

[1969FJ]

What year FJ40 ? Is harness all stock ? Any accessories ?

 

[pb4ugo]

Start pulling 1 fuse at a time that are hot without the key on until the draw stops. Then the reat of the fuses 1 at a time. Probably with the key off. Do you have any added accessories. Then maybe the alt wires.
I usually check batt voltage with it disconnected. Then hook up possibilities lead and use a voltmeter, post to Ned lead and negotiate lead to batt post and see if there's s difference in voltage, then do the fuse thing.

 

[ToyotaMatt]

I'm getting a significant 11 amp parasitic draw from the battery.

I've narrowed it to the single positive line heading from the battery towards the fuse block, but it seems to be happening before the fuse block.

What might be the most likely culprit?

Ignition switch?

I did reinstall the instrument cluster recently and ignition switch /column during the restoration.

Amp meter shorting or touching something behind the panel?

Thanks for any pointers.

if you have parasitic drain between battery and key switch , then your internal rotary contacts are worn and touching each other

OEM Toyota GENUINE PARTS Ignition Switch Key Lock Column Type Fits 1973 - 1984 FJ40 , FJ55 FJ45 84450-60070 Direct Interchangeable # 84450-36011 , 84450-60050 - VintageTEqParts.com

OEM Toyota Ignition Switch Key Lock Column Type Locking And NON-Locking Column Fits 1973 - 1984 FJ40 , FJ55...

vintageteqparts.com

 

[middlecalf]

11 amps is beyond parasitic.

 

[SteadiCruiser]

Thanks for all the responses.

11 amps is beyond parasitic.

Feel like an idiot with the new meter in the garage.

That's now .11 Amps.

Is that within FJ40 standards?

Still seems a little high and I did have a dead new battery which started the search.

Should have also clarified that it's a stock 74 truck and restored harness with the 30 amp gauge in the cluster.

I was able to make sure it was nothing beyond the fuse block (the way pb4ugo's pointed out helpfully) and the winch, starter and alternator have been tested and ruled out as well.

Great suggestion Matt about the ignition switch but I feel I can rule that out as it's fairly good condition and the draw is the same even with the ignition switch disconnected at the connector.

Makes me think it might be the amp meter mounted wrong or touching something it shouldn't in that cramped area behind the cluster.

Michael

 

[middlecalf]

0.11 amps is a lot better than 11 amps, for sure . But there shouldn’t be any parasitic power draw on an OE rig with the ignition off. If something non-OE was added (like a clock or radio with presets) then that’d be different, the draw specs would be specified in that equipment’s specs. If the amp meter was accidentally grounded, you would be in the 11+ amp realm but there’d be something burned up then .

 

[1969FJ]

It was mentioned in this thread to pull one fuse at a time. I would pull all fuses and see what you have. If drain is gone , one at a time until circuit is found.

 

[ToyotaMatt]

it's a SHORT in the ROTARY switch

Thanks for all the responses.



Feel like an idiot with the new meter in the garage.

That's now .11 Amps.

Is that within FJ40 standards?

Still seems a little high and I did have a dead new battery which started the search.

Should have also clarified that it's a stock 74 truck and restored harness with the 30 amp gauge in the cluster.

I was able to make sure it was nothing beyond the fuse block (the way pb4ugo's pointed out helpfully) and the winch, starter and alternator have been tested and ruled out as well.

Great suggestion Matt about the ignition switch but I feel I can rule that out as it's fairly good condition and the draw is the same even with the ignition switch disconnected at the connector.

Makes me think it might be the amp meter mounted wrong or touching something it shouldn't in that cramped area behind the cluster.

Michael

if your 30AMP meter was touching something , your cowel harness would be ASHES instantly , as that's full battery voltage going in to and thru it

 

[whitey45]

You should have no more than a 50 ma draw. As Paul mentioned there is nothing on a 40 to cause a draw? The way I check for a draw is to hook up your meter on the neg post( disconnected in line and set to ma. Then you can start pulling fuses, anything electrical really. As a german car tech, I have found many draws. One weird one comes to mind and could be your issue. It was on a porsche 911. It had a big draw and could not find it after a couple hours! I finally had it on the rack and noticed a weird glow by the starter. It turns out the main starter power wire was touching the heater pipe( aircooled porsche uses hose with wire to extract heat from the exhaust)( its like a covered slinky! Well the wire was glowing and causing the draw!! So you never know what might cause a draw!