battery drain in multi-purpose fuse box

[jrbach]

After reading what seems like 100s of threads through the search, I was happy to find a great description of the proper testing method using a test-light in series. I also found the list of components that go through the 10A "Room" fuse in the multi-purpose fuse box (let's call it the MPFB for short). Less than 1/3 of the people looking for help ever bothered to come back and post results, making the "required job" of searching first a long drawn out pain.

With the neg cable off...I removed the wires going to the 80A fuse (in the box front of right strut tower) at the battery. The light went out, so I removed the wires from the alternator side of the 80A fuse. The light stayed on, so I studied the schematic to see that power feeds not only that 80A fuse, but also a power rail. A wire from there goes to feed the MPFB, which is when the fun started. When I pulled the 10A "Room" fuse (I believe it's denoted as #19) and behold the test-light went out. There's quite a long list of items on that fuse...thanks DSM, for putting all that on one fuse.

The manual I have does a pathetic job of showing anything, especially since it's really cramped under the dash. I removed the left side panel and then the 10mm nut at the base of the MPFB. It must be held up above somewhere, but I can not tell where. I'd like to get the MPFB turned around so I can determine the offending circuit. It would be great if they were connected by a plug so I could jumper each circuit to find the offending one. Any good descriptions on how to remove and work with the MPFB to nail this problem down? Cheers

 

[92AWDHX40]

it does comem off pull it from the top after you removed the bottom nut i replaced my entire one with antother, its just going to show plugs. but whats the problem, thats a lot to tacked the one fuse to other items, 10 i belive its the room and linked to the radio, possibly others. not sure exactly what your looking for. 80 fuse is for the altenator, it goes to the battery and the fusebox outside the car it gives your fuse box power.

 

[jrbach]

iugrad92turbo...thanks. You wrote just "pull it from the top". How is it connected and where do I pull from? There are relays, etc, directly above what looks like the fuse box frame. I can't tell where it ends (where the "top" is) or where it connects at, so pulling on it from the top is a bit unclear. I'm hoping not to snap the frame and quadruple my problems. Any chance you know exactly how it is attached?
I thought I was being perfectly clear that something connected to that 10A Room fuse would seem to be what's causing the drain. If I can get that box turned around...there's got to be a way to test which wire is the cause, rather than just start chasing each and every connection, hoping the offending wire is found first and not last.

Any chance somebody has a picture of one out that shows it complete with how it attaches at the top?

 

[luv2rallye]

Unless you're absolutely sure the short is in the MPFB, disconnect each item from the list of items on that fuse and watch the light to find the failing component.

 

[jrbach]

luv2rallye...thanks, it was your "how to test" that I read...nice job.
I don't believe I ever wrote that "the short is in the MPFB". I did write that the offending component must somehow be attached to the ROOM fuse. What I did ask for help on was...how do you detach the MPFB? I removed the nut holding it on at the bottom, but I have different answers as to how to remove its upper connection. I have received one suggestion for just "pull it from the top". I have another suggestion that there's "a plastic clip that holds onto a metal bracket. You have to stick a flathead in between the clip and it slides easily out of place."

Ideally (IMO), there would be a connector on the back that I could simply disconnect and then jump from the supply-side to each component's pin to find the offending one. I'm not opposed to disconnecting all the wires feeding from the ROOM fuse and attaching them to a multi-pin connector whereby easy testing of each could be made in the future. It seems like a lot more work to run down each circuit instead of quickly finding the offending one. Especially when a different bulb (or whatever) could cause the same problem the very next day.

Any chance somebody has a picture of one out that shows it complete with how it attaches at the top?
Thanks

 

[luv2rallye]

I haven't seen the 1g inside fusebox's guts but if it's like the 2g one, it has a metal junction block circuitry inside that you can't see which connects various connectors pins to other connector pins. So you would have to first identify which outbound connector has the short - probably by unplugging them 1 at a time and watching the light. Note that you can replace the problem fuse with the light (it doesn't have to stay at the battery).

 

[jrbach]

luv2rallye...thanks, with a light, mirror and reading glasses (owned it since 93...eyes are 17 years older...)
I've since realized what a noob I am, as there's no good way to tap into that fuse box to do any tesing. Moreso with the lack of verified info as to how to remove the fusebox.

Taking your advice...I started with the last job I outsourced: the radio (tore the whole thing out). It is possible I never let it sit for more than a couplel days since those goofs slapped my stereo system together. It has sit too long for a long time, and each time the battery was run-down. I just never had time to deal with it before and left the battery disconnected.

When I connect the test lamp now, I get a strong light that fades to nothing over an ~7 second period.

Anyone have the schematic for the original stereo wiring diagram for the 1G system? I couldn't find it in my Chilton or the online manual from the weblink supplied at this forum.

 

[luv2rallye]

When I connect the test lamp now, I get a strong light that fades to nothing over an ~7 second period.

Is this when you connect the battery? Because capacitors act exactly like that when initial power is supplied which is normal (although it usually doesn't take that long). Do you have a huge capacitor in an aftermarket high power stereo amp?

 

[jrbach]

luv2rallye...thanks...if when you write "connect the battery",you mean connect the test-light to the neg-cable...then yes. I have no special stereo/amp and the stereo is totally disconnected.

Originally, I was only touching the test-light to the neg-clamp, so I was only seeing it as a bright light and wasn't waiting to see that it would actually dim to off. When I attach the test-light in series between the neg. term and the neg. cable, the test-light starts bright and then dims over ~8 seconds, but it then goes out and stays off...so maybe not really a problem? Can someone please confirm that? Thanks

My fairly uneducated guess is that the interior light timer circuit gets activated and then slowly cuts the light off as it normally would (such as getting in and closing the door).

 

[luv2rallye]

Yes you are correct about the interior light timer circuit is what causes the test light to go from bright to off in 8 seconds. I thought this was only when you close an open door/hatch though. So are you saying it also occurs when you hook up the battery and the door/hatch is already closed? My Eclipse doesn't do that. Perhaps the 1g is different OR more likely because the power up state of the light timer circuit is unpredictable, yours just happens to go that way OR perhaps that is a result of a problem (you previously mentioned a buzzing sound in your previous post).

 

[jrbach]

luv2rallye...thanks...perhaps someone with a 1G can confirm the test-light coming on and then dimming out when connecting in series between the neg-post and neg-cable. After I'd written about the whir-buzz upon opening the passenger door, it occurred to me that the seatbelt is always retracted on the driver's side and that the passenger side seatbelt retracts when you open the door. I believe the motor was actually trying to retract that seatbelt.

I took an ampere measurement with the test-light still in series and it seemed low. I then remembered there's a surge when making the connection, so I left the test-light in parallel while connecting the ammeter, but forgot to detach the test-light.... I measured ~27mA, but this is without the stereo installed (which did appear to have the correct wires connected, but was just a really pathetic physical install). I'll rerun the tests again after I reinstall the stereo. I read that anything below 65mA is reasonable if there's stereo memory added to the ecu draw. If there was a problem (and not just my imagination creating one), it doesn't look like one currently exists. So...I'm going to hook up the battery, start and warm her up, drive around and then park her for a few days to see if the battery voltage drops.
Thanks for everyone's patience and help.

 

[92AWDHX40]

if i missed it you checked your alternator voltage?

 

[jrbach]

iugrad92turbo...you asked if I checked my alternator voltage...
Should I have checked the alternator voltage? My first test was with the alternator wire from the 80A fuse disconnected at the alternator and then again where the alternator wire attaches to the 80A fuse.

The battery had run down to just over 12V after sitting disconnected for a few weeks and running all the tests I mentioned. Upon starting...I measured 14.5 volts (at the normally higher idle after having the battery disconnected) across the posts. I'm going to assume the voltage regulator is working fine and am not suspecting the alternator. She started fine, warmed up and found idle, and then drove fine at all speeds. Everything (door locks, seatbelts, etc) seems to operate just fine. I've parked her and will see if the battery voltage drops to less than 12V after a few days. If all goes well I won't need to update other than to say this is resolved and to acknowledge that I'm a paranoid noob...
Thanks

 

[92AWDHX40]

Hey you live and learn, good luck..