Gen 3 Parasitic Draw- SOLVED

[sidecardog]

Hi Guys,

I have a parasitic draw issue and I am at my wits' end trying to fix it. Any advice would be greatly appreciated.

I have a 2002 Montero Limited. All of my electricals are stock with the exception of a CB radio with power tied in to my cigarette lighter, and installed 9 years ago. I have not had any electrical issues of any kind prior to this. I woke up one morning a few weeks ago and the battery was dead. I had it tested and it tested fine. After two more mornings of dead battery I ran a parasitic draw test and found that my hazards/blinkers circuit was drawing 3 amps with everything turned off. If I remove the fuse for that circuit the draw drops to .17 amps. This still seems a little high to me but I have not been able to find another draw.

I have disassembled most of the dashboard and removed the left fender to check the wiring. I have not found any evidence of wear or bare wires and all wires look in excellent condition. My temporary solution has been to take the fuse out whenever I park at home for the night. I have forgotten to do this on four occasions, and on one of those occasions, the battery did not drain. I cannot identify anything that I did differently on that night.

It is my understanding that checking the hazards and blinker relays is not an option because they are built into the ETACS unit. Can someone confirm this for me?

I have disconnected the hazard switch and there was no change to the draw.

I have disconnected the blinkers switch and there was no change to the draw.

Does anyone have any suggestions for what to check next? I know that I can add a switch to the fuse and turn off the circuit from inside the cab if I don't find a solution but was hoping that someone out there may have found a fix.

Thanks
Matt

 

[EpicPlanet]

Hello, sidecardog, and welcome!

Since you have your dash apart, maybe test the circuit(s) at different points to narrow down the search.

Can ETACS be reset with a full power drain? Disconnect both battery cables, then turn on everything to drain any component-level stored power, capacitors, etc.?

 

[Michael Brown]

If you don't already, grab an FSM from my signature. There are wiring diagrams for the vehicle which will help you.

You will need a decent multimeter which can check mV readings and possibly mA.
It may take a while for the ECU to go to sleep which will show some draw.

Watch both of these videos for the method to test the fuses and calculate amperage from voltage (mV) readings.

Note that the light diagnosis tools may skew readings as incandescent bulbs pull some power as well. This is shown in the second video when his draw at the device doesn't match the total draw seen on the battery.

 

[sidecardog]

If you don't already, grab an FSM from my signature. There are wiring diagrams for the vehicle which will help you.

You will need a decent multimeter which can check mV readings and possibly mA.
It may take a while for the ECU to go to sleep which will show some draw.

Watch both of these videos for the method to test the fuses and calculate amperage from voltage (mV) readings.

Note that the light diagnosis tools may skew readings as incandescent bulbs pull some power as well. This is shown in the second video when his draw at the device doesn't match the total draw seen on the battery.

Thanks everyone for the help.

I don't see a 2002 FSM on the FSM link in your signature. Suggestions? I'm reading thru the 2003 to get familiar with how to read the circuit diagrams in the meantime.

 

[Michael Brown]

2003 should be close, but the Pajero NM for the 6G7 series motor would be correct in everything but driver side.
The 2003 was mostly similar, but I wouldn't be able to tell you wiring differences between them. The newer 3.8L engine went to throttle by wire instead of cable so there are likely several differences for the engine bay.

Based one your diagnosis, there is likely either a short or something else is powered from that same circuit.

 

[sidecardog]

Problem has been solved! Thanks for your help guys. The service manual might have not been the right year but enough of the 2003 manual was correct to help me identify the source of the draw. The manual identified that the voltage regulator for the alternator draws power from the turn signal circuit. I unplugged the alternator and the draw instantly went away. So if I had checked this first I could have saved myself two days of tearing the car apart. Oh well, lesson learned.

The first thing I did when I discovered that there was a parasitic draw was to check the individual circuits in the under-hood fuse box to find which circuit it was on. When I saw that it was on the turn signal circuit I didn't even consider that the alternator might share the circuit. That being said, just about every general video about parasitic draw on youtube says to check the alternator first so I should have at least considered it. In most cases they point out that oil dripping on the alternator can get into the plug and make it draw current when off. My alternator was extremely clean so maybe the plug had come loose or had some random dirt in it. I blasted both ends of the plug with electronics cleaner and used a toothbrush wherever I could. That was a few days ago and I have not had a problem since. Thanks again for the help.