vipernicus42

iTrader: (4)

Hey Guys,

So I've aparently developed a slow drain in my electrical system. If the car is left 2 or more days on its own the battery gets discharged so bad that I need to put it on a charger for a few hours.

So since I didn't have this drain last year, I outlined the things I've changed this spring in the electrical system. Now I have to figure out how to troubleshoot them.


Things I've changed:
- Added FC Fuse box (unlikely to cause the problem, simple install, no real room for errors)
- Added e-fan (possible, it works on a constant +, and a ground-switch)
- Trimmed passenger wiring harness to remove rat's nest connectors and a few others (most likely, I just cut them at the connector).


And there's a very *slight* possibility it's the alternator, because I ran a new constant 12v wire for the terminal that needed it. Shouldn't make a difference though. Last year it was a wire going to the + terminal on the battery, now that same wire goes to the + connection where the battery cable meets the FC fuse box.


I have a digital multimeter, but the only "current" setting it has maxes out at 10amps and it's unfused, so if I go above 10 amps it'll blow my multimeter.

So how do I go about testing? Any suggestions?

I'm pretty sure it's coming from the main fuse, because if I remove the main fuse, it doesn't drain, but if I only remove the fan fuse, it still seems to drain. (fan is on its own seperate constant 12v fuse from the fuse box).

Jon

85 FB

Sounds more like an e-fan problem. Wiring up an FC fuse block wouldn't do anything, just because of the fact that a fuse block of course requires constant power. I'd double check the connections on the e-fan or possibly the alternator. Mine has the power wire looped on itself, as you've seen from the pictures, and I've had no battery drain whatsoever when it's been sitting. You could try that, see if that works.

With the e-fan, the only reason I could see for it to be on a constant power source is if you had a 3rd Gen setup where the fan will continue to run after the engine has been turned off to help cool the engine down. I'd start with the e-fan first and then the alternator if that still doesn't fix it.

vipernicus42

iTrader: (4)

Good idea. At least it would let me eliminate the alt as a possibility for now.

Yeah, I was thinking e-fan... so here's a question:

The e-fan has it's own fuse. IF the fan is off, and I put a voltmeter on the fuse, should it show 0v? (cause it isn't grounded)

Jon

gsl-se addict

iTrader: (3)

Hey Jon,

I would take a look at that FD alt. If it is wired incorrectly, it will cause the battery drain that you are having. It should not use both stock alt wires. Needs one to constant battery + and one for the alt warning light. It sounds like you did it correctly, though. If you keep having trouble, have the alt tested. If it is bad, it can cause drain.

Perhaps some wire that you cut are grounding out? Is the battery okay? Maybe get it tested to be sure. On my SE, the current used when everything is off is about 20mA (about 120mA while the light for the ignition cylinder is on, drops to 20mA once it goes out).

Good luck.

85 FB

If the e-fan is on a constant power supply, having it on the fuse will still show current. I THINK. Why is your e-fan on constant power? I've never installed an e-fan so I don't know if the setup requires a constant power or not. In my opinion, I could see it being beneficial on switched-power but then again, I don't know if there are any switched-power connections inside the engine bay.

And, after thinking it through, I'm thinking that that may be the problem. Something is constantly draining that battery and usually when that happens, it's a bad wiring setup, not an alternator.

Hope this helps. Give any more information you come across, I've had my fair share with electrical setups and whatnot. I love me some wiring.

64mgb

iTrader: (1)

If all else fails, start pulling fuses, one at a time, and see if the drain goes away. This will take some time because you have to wait for a couple of days. Or, you could put your ammeter in series with the positive lead on your battery and measure the current draw (nothing on, just sitting there). Typically, this should be very small, maybe unreadable, depending on what you have on your car that is under constant power (clock?), although I've never checked to see what any of mine read. If you get a reading, then start pulling fuses, one at at time and watch for the current draw to drop. If it does, you've found the circuit causing the problem. The it's a matter of tracing back to everything on that circuit.

Hope this helps Jon...good luck!

Rich

gsl-se addict

iTrader: (3)

So, the e-fan is without a relay? Or is it on a relay with a switch to the trigger? Anyway, shouldn't matter. The fuse will show voltage (referenced to the car's ground), but there will be no current as the path is broken by the relay (or switch). The e-fan is probably fine unless there there is some wiring issue.

If you are worried about testing current with your meter, you could wire an inline fuse to make sure the meter is protected. The other option is to wire a resistor inline (say a 5-10 ohm power resistor from RadioShack). This will limit current to 1 ro 2 amps. It will throw off the current measurement, but that doesn't matter. You are mainly trying to see if a circuit is drawing 0-xxmA or drawing closer to 1A or more.

trochoid

iTrader: (6)

The e-fan will only drain the battery if it is on. I have the power to mine coming from the FC fuse block, but I have it relayed, with the relay pulling switched power from the + side of the trailing coil.

If you're worried about blowing your multi-meter, add an inline 5 amp fuse to the + lead. If it's taking 2 days for the battery to drain, I doubt the drain is over 10 amps, but I'm and electrical idiot most of the time.

64mgb

iTrader: (1)

Yea, you're safe putting the ammeter in line with the battery lead, as long as you don't try to start the car with it there. If you were drawing over 10 amps it wouldn't take two days to drain your battery.

Rich

85 FB

Usually, when it comes to a drain, it's a wiring issue. Sometimes just a grounded connection, altho normally that'll spark something, but usually a bad connection. Double check your connections and their leads to make sure that they are going to where they're supposed to be going. Let us know how things work out. Troubleshooting is generally the best, and sometimes only, way to figure something out. As long as you have decent wiring connections and not a horrible rats nest.

vipernicus42

iTrader: (4)

AFAIK the FD alt is wired up correctly. It wasn't causing a drain last year, and yeah I do have one wire going into the stock harness, and the other one going to a constant 12v. The alt works, because even with the battery completely dead, I can give it a very small boost from another car, then mine runs for hours.

Yeah, wires that I cut could be grounding out. I've had the battery tested (it's still under warranty so I tried to return it the first time it died thinking it was bad) and it tests good once charged.

20mA isn't much, I'll have to check that on the main fuse.



My e-fan is hooked to a temp switch. It was either in the instructions or something in the way the previous owner had it that made me wire it that way. The fan itself has two wires, one for 12v+ and one for ground. The 12v+ always has power from the battery, and the ground wire goes to the temp switch, which completes the connection to ground when it's hot enough. It seems to work like a charm, but I want to see if that could be the slow drain.



Yeah there are only 2 fuses to pull. I *know* the drain isn't coming from the headlights or retractor motors, so that only leaves Main and E-fan.

For last week, I just pulled both of them every time I parked the car. That stopped the drain. Now I'm trying just removing Main, we'll see in a few days what happens.

But yeah, if it's on main, then I'll have to start pulling fuses in the in-car fuse box, and trace that back.



It's on a temp switch. I'll dig up which one in a bit


Yeah I figured that much for power-off, but I wanted to compare e-fan ON to e-fan OFF and see what it would do, but I *know* the efan pulls more than 10a when on.



Thanks for the help guys. I've gotta head out for a bit, but I'll keep you updated, and look up that tempswitch for your info later.

Jon

vipernicus42

iTrader: (4)

Okay, so with the car off, the MAIN fuse draws 260mA and the EFAN fuse draws 0.

So it's not my efan (thankfully).

260mA seems like more than double what someone else mentioned the draw would be, but it also doesn't seem like a lot to me. Is that enough to drain my battery in 2-3 days?

I guess it must be, unless I've got drain through my starter too (the only other place the + battery cable goes. Fuse box and starter).

So now I guess I go to the in-car fuse box and start pulling fuses. I've already pulled the 20a "ENGINE" fuse and it did nothing. Now to try the others I guess. Something tells me I won't find anything from that fuse box.

I'm going to try unhooking both the connector and the big + from the alt and see what it does.

Jon

64mgb

iTrader: (1)

I'm just guessing, because I've never measured current draw with everything off, but that seems high to me...1/4 amp is quite a bit.

Rich

gsl-se addict

iTrader: (3)

Jon,

You can remove the - battery cable and put the meter in series between the cable and the battry -. This will give the total current draw on the system. 260mA seems high, but I don't know if that is enough to kill your battery like that.

As a reference, mine is 20mA everything off. 120mA everything off except for the ignition key light. So your 260 mA would be equivalent to about 2.5 times what the igniton light uses (not too much). 260mA would be just over 3W of power. I know the small lights for the instrument cluster are 3.4W each to give you the idea of the power you are using.

Anyway, try the meter inline with the - cable. If it is the same, leave the meter connected and have someone start pulling fuses in the car until it drops. The you will have to go through that circuit to see what is causing the drain. It doesn't seem like 260mA would be enough to kill the battery that fast. It is more than 10x what my GSL-SE uses with everything off, though. Also, try removing the alt output cable as you mentioned. Good luck.

Kent

trochoid

iTrader: (6)

Here's a couple of silly things to look at. The hatch light, you won't notice it in the daylight. I don't remember is you have a GSL or not, check the wiper switch, front and back and make sure they are off, along with the dome lights.

vipernicus42

iTrader: (4)

Check, check and check.


I'll try putting the multimeter in line with the - terminal. Why the - terminal instead of the + terminal??


Jon

trochoid

iTrader: (6)

Always remove the negative lead first, it's safer. No fun arcing a wrench taking off the positive lead first.