Hi everyone,
I've been suffering a parasitic drain on my 1999 4.0 TJ for the past year, and I'm totally dumbfounded as to what could be causing it.
It used to be my Dad's jeep, and unfortunately, I don't have his skills to keep it running.
I've read a number of threads on here and elsewhere, followed the youtube tutorials etc, but nothing seemed to help.
At the beginning of the year, I had problems with high rpm at idle and while driving – pulling at junctions and wanting to slow down even less than usual.
Took it to our local reputable garage and they replaced the TPS sensor, IAC valve, distributor cap and spark plug wires. Seemed to solve the problem temporarily, but it soon returned.
At the same time, I started having problems with the battery draining – took it back to the garage, and they replaced the battery and cleaned the throttle body again, but again the problem returned.
Tired of taking it back to the garage again, I read up more on the issue, and some people suggested the downstream O2 sensor – so I replaced this myself with an NGK part. It ran perfectly after I swapped this – until I left it overnight and the idle issues returned the next day. This time it would start with low revs, needing gas to stop it stalling. It would occasionally start fine but then fly up to ~1600rpm in park.
Putting the idle issue aside, I'd like to identify the parasitic draw.
I followed the tutorials on parasitic drains – disconnecting the negative cable, running a multimeter in series, with all doors closed, left off for 30 minutes etc... which resulted in a reading of 0.22 amps.
The battery reads 12.8V across the terminals with the engine off, 13.93V when the engine is running.
I have been charging the battery with a maintenance charger intermittently.
Following advice on here, I read the voltage across each fuse in the fusebox behind the glovebox and under the hood – nothing.
I pulled every fuse one by one, keeping an eye on the amp reading – but no change.
I pulled every fuse and relay all at once – still no change, still showing 0.22 amps.
I removed the interior lights, aftermarket radio and checked for any aftermarket alarm etc – still no change.
Further advice pointed to the alternator, starter or PCM, so I disconnected the wires to all of them – still the draw persisted.
Most recently, when I charge the battery and turn on the ignition, I can hear a relay under the steering wheel clicking on and off randomly.
Using a jump battery, it still starts, but it's rough as hell and stalling out without applying some gas – I assume this is because I am leaving the battery leads disconnected, so the PCM is resetting each time?
Any other ideas what could be causing this, or what I'm doing wrong?
Any advice is really appreciated. If anyone can recommend a Jeep specialist near Hampshire in the UK, that would also be appreciated.
Thanks
Craig
I've been suffering a parasitic drain on my 1999 4.0 TJ for the past year, and I'm totally dumbfounded as to what could be causing it.
It used to be my Dad's jeep, and unfortunately, I don't have his skills to keep it running.
I've read a number of threads on here and elsewhere, followed the youtube tutorials etc, but nothing seemed to help.
At the beginning of the year, I had problems with high rpm at idle and while driving – pulling at junctions and wanting to slow down even less than usual.
Took it to our local reputable garage and they replaced the TPS sensor, IAC valve, distributor cap and spark plug wires. Seemed to solve the problem temporarily, but it soon returned.
At the same time, I started having problems with the battery draining – took it back to the garage, and they replaced the battery and cleaned the throttle body again, but again the problem returned.
Tired of taking it back to the garage again, I read up more on the issue, and some people suggested the downstream O2 sensor – so I replaced this myself with an NGK part. It ran perfectly after I swapped this – until I left it overnight and the idle issues returned the next day. This time it would start with low revs, needing gas to stop it stalling. It would occasionally start fine but then fly up to ~1600rpm in park.
Putting the idle issue aside, I'd like to identify the parasitic draw.
I followed the tutorials on parasitic drains – disconnecting the negative cable, running a multimeter in series, with all doors closed, left off for 30 minutes etc... which resulted in a reading of 0.22 amps.
The battery reads 12.8V across the terminals with the engine off, 13.93V when the engine is running.
I have been charging the battery with a maintenance charger intermittently.
Following advice on here, I read the voltage across each fuse in the fusebox behind the glovebox and under the hood – nothing.
I pulled every fuse one by one, keeping an eye on the amp reading – but no change.
I pulled every fuse and relay all at once – still no change, still showing 0.22 amps.
I removed the interior lights, aftermarket radio and checked for any aftermarket alarm etc – still no change.
Further advice pointed to the alternator, starter or PCM, so I disconnected the wires to all of them – still the draw persisted.
Most recently, when I charge the battery and turn on the ignition, I can hear a relay under the steering wheel clicking on and off randomly.
Using a jump battery, it still starts, but it's rough as hell and stalling out without applying some gas – I assume this is because I am leaving the battery leads disconnected, so the PCM is resetting each time?
Any other ideas what could be causing this, or what I'm doing wrong?
Any advice is really appreciated. If anyone can recommend a Jeep specialist near Hampshire in the UK, that would also be appreciated.
Thanks
Craig
