legacycentral bbs

The 1st part of the problem started about a month or 2 ago, and I assumed it was the radio getting old. When the wipers were being used the radio volume would drop, then build up again, then drop again when wipers engaged.

Then the radio went out altogether, sometimes from using the wipers. I figured it was a fuse, but couldn't find any. The radio came back by itself after a day or so, but the presets and clock were still set.

This happened a few times, then the plot thickened. I noticed also that only sometimes while driving after a short space of time, as if to build some kind of electrical momentum somewhere, on stepping on the brake the dash lights would dim, a little anyway. This may or may not be a symptom.

Then the wipers would cut out when the radio cut out, but come back after a day or so. Again, radio time & presets fine.

Lastly, & this is the big issue - wipers, radio, power in cigarette lighter, mirrors, horn, windows, moon roof, and taillights and front parking lights out, but not headlights or turn signals, hazards. Parking light switch on column will still light them up, but not headlights switch. Cabin lights and dash lights all fine, brake lights fine.

Mechanic friend suggested that a 50 amp or larger fuse that runs those subsystems was loose and making bad connection.

I've been looking for a schematic but can't seem to find one. Also, for some reason I'm thinking there's a fusebox located behind the glovebox? I don't know why that's stuck in my head.

Not having much fun as moon roof was stuck open and now it's cold and wet, so of course that's when it happens. Screwed if it rains, b/c I have no wipers. Jeeeezzzz!

1994 legacy wagon ej22t 4eat

Hi,

Someone with experience with this problem will hopefully answer you soon.

But from my 1990 wagon manual:

Main fusebox (M/B) is under the hood, between battery and wiper fluid.
Other fusebox is in passenger space, on the left sidewall below the side mirror control. There is a light (that comes on when you open the door) on this fusebox, but bulb might be dead.

Radio has two power sources, and power antenna a third.
Wipers are fed from ignition only.

Radio and wipers run thru ignition switch, fed by SBF-4, a 45 Amp fuse that lives in the fusebox under the hood.

I will look at the rest of the devices later.

Also, most heavy loads are fed by a relays, whose coils are fed by a different path.
Your problem is a loose connection, which can occur many places: fuseboxes, relays, switches, etc.

Dale

I didn't finish, but my ramblings indicate the ignition switch, or the line to it which supplies 12 volt power.

According to my schematic, a connector named B63 mates with ignition switch. It carries lines which feed the dead devices. It also has 2 lines that go to the main fuse box.

Tracing back to battery:
The other end of this cable (2 lines) is B25.
B25 mates with F46.
The other end of F46 is connector F38, which plugs onto the fuse box in the engine compartment.
The fuse it connects to is SBF-4.

Radio and Front wipers are fed thru B63 pin 2, which is hot in 'Acc' and 'On' key positions.
Windows and roof are fed thru B63 pin 5, hot only when key is in 'On' position.

If it is the ignition connector, either:

connector is falling off, or:
connector terminals are in a death spiral.

Could be the ignition switch contacts are in a death spiral.

Someone (Josh, I think) has posted schematics someplace.


Radio: FB-13 link is switched but MB-8 is not; keeps presets.

I meant to mention before loose connection has 50% prob of being chassis Return "Ground" (not germane to most recent analysis).

I will respond to all questions you might have.

D

Thanks D for the reply. Very good info in that.

Didn't get a chance to check any connectors, but did do a quick check to make sure all sbf's were seated well.

New wrinkle popped up its head tonight. Now auto shoulderbelts have stopped working.

Briefly had power windows and power in sun roof, along w/power in heater blower motor. Horn, taillights, cornering lights, cigarette lighter power, power mirrors, radio, wipers still all dead in that brief spate.

I will check to see if ignition switch connector is perhaps loose. Also have spare ignition switch so might try swapping that out.

I will hunt around to see if I can't find the schematics you mentioned.

I would like to get this straightened out because, among other reasons, I have to remember to engage parking lights @ night or else its ticket time. So after working late tonight I of course forgot. Nobody needs an avoidable ticket in this day and age w/insurance rates being what they are.

Thanks again,
sc

It sounds like you've got a bad ground, possibly a chassis or engine ground. Or possibly a short some where. My suggestion would be to check all (or as many as you can) of the chassis ground locations. Check to make sure you have near 0 ohms between the negative terminal of the battery and the ground point. It may not also hurt to add extra ground leads.

Another thing that might help is to get the alternator & battery tested to make sure they are working properly. If you do all this and you still have the problem, you've likely got a short. The easiest way IMO to test this without super fancy tools is to pull all the SBF's in the main fuse box. One by one, insert the SBF's and see how things work once each SBF is inserted in the fuse box. If everything works ok, and then all of a sudden doesn't when a new one is put it. You know that the short or issue is in that circuit. You can use the wiring diagrams to narrow down the circuit and can do the same thing if there are multiple fuses in the driver's foot area fuse box.

The service manual link/info is in the stuff you need to know forum.

Thanks for the help. I believe that these two diagrams should be what I need:

http://surrealmirage.com/subaru/files/s ... uting2.jpg
http://surrealmirage.com/subaru/files/s ... uting1.jpg

Only real problem is this is my 1st shot reading wiring diag's and it sorta looks like Chinese to me.

Until I puzzle it out a little bit it's a fun game of which electrical component in my car is not gonna work today.

I'll post the results once I locate the culprit.

Thanks again to all for the help, and thanks Josh for making the diagrams available to all.

You are fortunate in that you have wide-spread failure! That will make finding the fault easier.

Seriously, don't get too bogged down by the schematics - the problem is something significant - not some tiny out-of-tolerance condition.
Turn the ignition to Acc or On; with the radio and wipers switched on and start moving things: wiggle the big things (wire harnesses, etc.) with your hands. Use a small mallet or the handle of a screwdriver to tap the small things.

Work your way from the ignition, under the dash, to the inside fusebox (my fuse is slowly burning up: stoplights died), (I would remove the 5? screws and drop down the panel below the steering column) then to the firewall. Then pop the hood, work your way to the other fusebox.

Grounds (chassis power returns): the first seven devices in your first post have 7 different ground-points (ring terminal lugs bolted to the chassis) mostly close to each device.

If you must mess with the "grounds", limit yourself to making sure they are tight-don't loosen them. Subaru uses a double internal and external -toothed washer- your chances of getting it back in place exactly are small.

If nothing turns up, expose the ignition switch and poke at it. (you said you had a spare - has it been worked on before....)

I did the following table to determine the common point for your failures. The manuals are more than complete, but you have to jump around to trace something, and it's easier to make a chart to keep track. Working upstream toward battery, looking for the point they have in common:

========================================================================================================


Alt Alternator
FL Fuse Link (a piece of wire)
PSR Power Supply Routing
SMJ Super Multiple Junction (connectors so huge they are held together with a 4mm diam. bolt- 10mm head)

You have chosen the two schematics involved, and most of my chart comes from them. The rest comes from the the two pages which follow the schematics in Section 6, the figure for each device, and the wire harness layout drawings (the last pages in Section (Book) 6). The "Ground" points are also on these pages.

I stopped doing the chart when I saw everything was coming from Ignition Acc or On. The few apparent exceptions answer some riddles: the radio has two connections; one direct to the main fusebox and one switched. Logically, one would not want the clock and presets to vanish when you removed the key. Also, the power amps appreciate more direct connection to the battery. (ramble ramble...)

The inside fuse box would be my second choice.

I've given up on making my chart a table - I'll post it somewhere else and add the URL here.

Post your questions- I'll check periodically.

Very good info and help. Thanks for sharing.


Other thing to note is that those diagrams you posted are from the 90 factory manual. You may want to use or at least compare those to the info in the 92 manual, since your car is a 94. The 92 is 100% complete on the electrical. I have additional scans from the 90 manual that are complete, which may at least lead you in the right direction, even if all the wire colors & pins aren't exactly the same.

http://www.main.experiencetherave.com/s ... and_Elect/

http://www.main.experiencetherave.com/s ... agrams.zip

Wow, tremendous effort D. Thank you. Lots of information there.

As the underdash is already exposed and I have jiggled the connectors quite a bit I am leaning toward another solution.

You mentioned connectors being in a death spiral. Just to split hairs does that mean that electrical connectors can suffer from a type of metal fatigue, just like metal under strain? This is more an fyi question than anything else.

And yes, I swapped out the ignition switch once before when it turned out it was just loose connectors at battery. Can you say well duh? The 2nd switch was not new, but junkyard salvage. I'd say 2nd gen legacy as you don't see 1st gen's often.

I think my next move is to check that the connectors under the main fusebox are not loose. If that checks out then I will swap out the ignition switch again. Since the original was not faulty it will do as a test module.

Since the ignition and main fusebox are major connectors I will work upstream from them if it turns out that they are not at fault.

As the faults are intermittent and widespread I am leaning toward the ignition switch being the problem, but we shall see.

I will try to put what you posted in table form and resubmit it when I do. As I said, a lot of good info there and I am often easily confused.

Josh: As far as the diagrams being for a '90 I did a quick and dirty hail mary and grabbed the 1st thing I could find. Thanks for pointing me toward a more complete set of diag's. and the tips about the grounds and sbf's and all. Will check them out as well.

I appreciate the time and effort of all and will post my result once the problem is resolved in the hopes of adding to the knowledge base.

In all likelihood it will turn out to be something simple. It's just my habit to panic to keep life interesting.

I appropriated the term "death spiral" from another discipline (aviation, I think). What I was referring to was heat, not metal fatigue. The connection generates more heat than it can dissipate at ambient temperature (through conduction, usually), and its temperature rises until dissipation equals generation. Of course, chemical and metallurgical degeneration accelerate at higher temperature. This causes increased resistance, and more heat. Unless a major change to the connection is made it's only going to get worse. Goes for electrical (switch) contacts, too. We have all seen examples of it, I just used a morbid term to describe it. BTW, metal fatigue can be involved in some cases, I think.

Next topic:
Section 6-3 (Electrical), 1992 version does not have the Load Table found in the 1990 version. 1990_Legacy_Wiring_Diagrams.pdf // Page 18 & 19 // 6-3 [0501] Wiring Diagram and Troubleshooting.
The table lists the all the loads (devices) connected to each of the nodes (MB-4, FB-2, etc.) defined on the two pages of wiring diagrams you mentioned. It then gives the figure that each device is detailed/elaborated on.

Third topic:
From the second wiring diagram page, you can see that your failed devices (at least the first few) are supplied by either the Acc or On (or both) terminal of the Ig switch. The actual distribution of power to the devices is done in the interior fusebox. If the problem is the Ig switch, then failure should be 100% of the devices fed from a failed line. If that is not the case, it would seem to indicate the fusebox is suffering from some sort of breakdown.

Fourth topic:
Submit button eats spaces. Tables don't seem to be turned on. Code preserves white space, but the SELECT button scares me.

D