jordan96xj

I'll try to make this as concise as possible.

At rest, I have too much amp draw coming from the battery. About 170-200mA

I ran through some testing, and narrowed it down to the following:

With the key NOT in the ignition...

1. Open driver door (amps of course go way up - dome light)
2. Green ignition illuminator ring comes on
3. Shut Door (dome light off - amps go down to proper range ~50mA)
4. After approx 10 seconds Green illuminator ring goes out automatically
5. When the illuminator ring turns off - the amp draw goes up to about 170mA

I looked through the FSM wiring diagram to try and make a connection between these things. But it isn't jumping out at me.

I'm not sure the illuminator ring is mentioned specifically in the diagrams at all. What I do know is that the door jam switch is what is causing it to illuminate.

In the FSM diagrams, I can see that the door jam switch does interact with the ignition switch. So for now I'm assuming that the ignition switch illuminator ring is also connected to the ignition switch as well.

In summary:

Any guesses as to why my amp draw would be normal when the illuminator ring is ON but then the amp draw goes high right at the exact moment that the illuminator ring turns off automatically.

djgrayxj

Note from DJ
Year of Jeep?
Any modification to the Jeep?
How do you lock your doors?
Alarm System Factory or Aftermarket and is it used?

jordan96xj

96 XJ Sport 59k miles
Manual locks, mirrors, windows
Stock stereo
No alarm system

DFlintstone

Meter Glitch? Radio memory? (pull fuse?)(is the memory wire fused?) .12 amps.mmmm

Side story. I have a nifty (cheap) led volt meter for my house batteries. Love it, reads to tenths and I can see it from across the room. Glitch is though, when I turn ON a 9 watt Led light, voltage goes UP 1/10th of a volt. Anyone's guess. At that tiny scale maybe some sort of resonance is messing with the meter.

jordan96xj

I'm starting to think it is a glitch. I can reproduce the numbers consistently. But I'm starting to think the numbers are high on the meter. I'm using an inductive amp clamp.

As a double check, I tested the battery at the end of the day for voltage at 12.66 then again about 12-14 hours later and it was at 12.56 volts. I think if I was actuall having the amp draw that the meter numbers were showing, I would have lost a lot more than that.

BlueRidgeMark

Hmmm. A general use amp clamp? It's probably not accurate at those low numbers.

Try an actual current test with the meter in line, and see what you get.

97grand4.0

Agree with the in line meter.
Mine had a draw that was related to the little switch on the back of the drivers and passenger door key cylinders, cheap little switch that breaks in the open position. bone yard part or $14 or so at some online retailers. Made the bcm think the doors were still unlocked. I know you say you have no alarm system, though.

jordan96xj

All signs point to my amp clamp giving me a high (but consistent) reading. I'll run another test with DMM in line (no clamp). I'll also check the amp clamp on a couple of known good vehicles and see if it struggles with measuring those low mA levels.

DFlintstone

87-90 Renix draws zero without the radio memory, ect.

BlueRidgeMark

Look up the model of clamp and see what it's rated for. That should give you an idea.

97grand4.0

DC amp clamps...I been licensed as electrician for 21 years, still don't have one. They are harder to come by $$$ than an AC clamp, but I do wish I had one. You certainly cannot rely on them at mA levels, though. Too much random interference.

BlueRidgeMark

That's about what I figured. Funny, in my 30+ years in telecom, I have never had occasion to mess with a DC amp clamp. I just figured from knowing the theory of them that you'd need something specifically made for that low range, or it would not be accurate.

97grand4.0

No. It's like trying to find a needle in a haystack. You have an wire through the middle of a 2 inch center of a ferrous metal ring, trying to sniff out the magnetic field produced by <10mA. Move the clamp a little, it changes. Guy next door starts his dishwasher, it changes. AM radio stations, tv, cell towers, etc etc etc, sunspots, moon gravity, all interfere at that level.

Beside that, an amp clamp is never completely accurate, only pretty close at best. You have to figure, it measures current by sensing the magnetic field, then using firmware to convert from magnetic field back to amps, thus introducing another (avoidable) layer of error. Better to just measure amps if it's accuracy you're looking for with an inline meter. Even those are subject to error, though some much less than others. Even the mid price digital volt/ohm/ammeters of the last 20 years are very accurate to within some spec that they publish.

Myself I have a $20 Sears meter works just great for measuring current in that range. Also a $5 meter I got at a farmers market, yet to try it, but I bet it's fine also.

BlueRidgeMark

If you have the right instrument, you can measure some pretty small currents. A young friend of mine is an engineer working on space defense stuff. He has an ammeter that will peg if you put it 10 feet in front of a CRT and turn it on.

97grand4.0

Cool. Yeah I was about to say, maybe some govt agency has developed a pretty accurate one but they have bazooka bucks. space defense would be where you'd find the extreme of that one, for sure!