Member
I have recently finished slipping an S54 into my E46 Sport Touring. All is running well. A couple minor things need attention, but are not real issues. HOWEVER, Something is killing my battery. It is new, accepting charges, and passes load tests. In doing a current draw test, after the car is fully shut down, all interior lights fade out, and snowing a .26 amp draw for about 60 seconds, the draw drops to .06 amp. I have eliminated the alternator "bleeding" the current. How? I removed the smaller power lead at the positive cable at the battery, and the draw went to zero. That smaller cable goes forward to the fuses and relays in and behind the glove box. Tomorrow I will be chasing systems by pulling fuses until the draw goes away. Not sure if there is a better way at this point. The disturbing aspect of this is that apparently the condition did not exist before the swap.
Anybody seen such a thing?
Member
The car will never have a zero amp draw. Even when fully asleep, there are still electronics doing business. Acceptable draw for an e46 fully asleep is roughly 27mA(0.027A).
Common issues on e46's are blower motor resistors.
Member
The usual culprit in an E46 is the final stage resistor (FSR). It’s usd by the interior climate control to manage the fan. Go to E46Fanatics to find out how to see if it’s the problem.
Member
Originally Posted by DrewMontE36
Good info. But a followup question --- HOW DID YOU KNOW THAT ?!?!?!?!?
- - - Updated - - -
Really ??
Member
Their web site has been down since yesterday.
Member
Update ..........
The draw, after about one minute of "rest time" drops to .06 amps. After a half hour, no difference. Pulling F41 immediately drops the draw to .01 amps. This is the same value as my E36 M3 after shut down, and it can sit for a month and start right up. The E46 has a fresh battery that accepts recharge and passes load tests. I have removed the aftermarket radio with no change. The car is VERY LOW content (three options - Sport package, metallic paint, and wood trim) so "features are not an issue.
So ------ who is going to be my new hero ?!?!?!?
Last edited by shogun; 02-26-2018 at 08:10 PM.
Member
The car will take about 15 minutes to completely go to sleep. If it's an automatic, you can tell if the car's asleep because the orange light on the shifter bezel will no longer be illuminated.
So if after half an hour your draw is still .06(60mA), then something is staying awake. What is fuse 41? 60mA is still fairly small, shouldn't be killing your battery very quickly.
Member
Turns out I am going to be that person. Buckle up -- this is WEIRD. NOTHING original to the car was causing the problem, but it WAS in the radio system. I installed a Pioneer double DIN radio. Part of the installation was an item that is a parking brake sim that allows the radio to be adjusted (equalizer, features, etc.) that normally can not be done without the parking brake engaged. You know --- A nanny killer. As I was diagnosing the drain, I took the opportunity to pull the head out to inspect the wiring adapter, and since I was having reception sucked, check the antenna leads. To check the reception, I removed the adapter from the car's harness to the new head, plugged in the OEM radio, and had great reception. Separate issue, BUT, I checked the drain with the adapter removed. No drain. Plugged the adapter back in but did NOT plug IT into the new unit. The drain returned. Off to the store I bought the stuff from, swapped the adapter lead for the antenna for the CORRECT one, and we discussed the SIM, as that was the ONLY possible cause. "I have sold a ton of them with no problems", so which I said "Oh REALLY?". After snipping the ground (his idea which I did agree with), no change. He came out to car to see, and then I said I was going to snip the hot lead to the SIM. "That won't do anything". Response? "Well, ground can't leak, but power CAN". He looked at me, I looked back, and then snipped the power lead to the SIM. "Well, damn!!" I stared at him and smiled. He returned my $20 for the part.
So, NEVER ASSUME !!!!!!!!!!!!!!!!!!!!!
Last edited by snaponbob; 02-26-2018 at 09:38 PM.
shade tree mechanic
Moderator
Maximum closed current by vehicle: E31 50mA, E32 50mA, E34 40mA,E36 30mA,E38 50mA,E39 40mA,E46 40mA,E52 50mA, E53 40mA, Z3 30mA
Performing Closed Current Draw Test
• Select proper measuring device (DISplus, MoDic or DVOM)
-Remember amperage draw in excess of 10A will damage DVOM.
-Use inductive amp probe of DISplus when amperage draw is high.
-When using DISplus inductive probe, clamp on negative battery cable with arrow pointing away from battery. Switch off all consumers. (It is not necessary to disconnect B- from body when using inductive probe)
• Connect (-) test lead to negative battery terminal and (+) test lead to a known good ground.
• Ensure all systems are OFF !
• Be sure DVOM is on and set in proper mode.
• Disconnect battery ground lead from body.
• Observe meter reading, wait 16 minutes for vehicle to enter sleep mode.
• Identify faulty circuit by disconnecting fuses, relays, control modules or connectors, observing meter readings.
• Defective circuit is found when current is below maximum closed current for vehicle being tested.
use this link for more details http://www.e38.org/battery.pdf
Shogun tricks and tips for the E32 series are HERE!
Member
Nice!
Member
Sounds like another case of "Mechanic's Rule" that an item installed by other than the factory (you!), is the culprit.
Charlie
Your mission, should you decide to accept it, is to add value to these threads, either by pictures or by descriptions, so the next person with the same or similar problem stands on your shoulders.
Member
True. BUT ....MY "rule" may be even more appropriate --- Just because a part is new does not mean it's any good.
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