Electrical Quandary

[Nomake Wan]

I actually don't have a light in the trunk. The trunk's pretty much a goner. But I'll check the wiring back there once I've finished with the rest of the checks.

[Nomake Wan]

Well, I checked those two fuses in the interior. They registered a 1.55 and 1.35 mA reading. Now I'm not sure why the door lock circuit is constantly energized (especially since I don't currently have a security computer) but maybe that's a Subaru thing. As for the EGI+AT fuse, it hit me why that's drawing power. Durr, it's the ECU. The ECU has to remember what it's learned. For it to remember it needs power. Else it wouldn't forget if you leave the battery out of the car.

So I've concluded that none of the interior fuse circuits are at fault.

I took apart the dash and pulled the instrument panel. Surprising to me, only one of the bulbs in the gauge cluster looked bad. Are the bulbs in series? That would explain why every light in the cluster except for the backlights work.

The rear of the dash switch assemblies all looked fine. A little shocking to see that the wires are just soldered on, but all of the wires were intact and no connections were crossed. I put the dash back together.

I also tried replacing the flasher unit. All that did was alter my flash pattern, not fix the strange power loss when the turn signals come on. The wiring for the flasher unit is all intact and good too, so the flasher unit's out too.

Which just leaves the turn signal stalk, or wiring from the under-hood fuse box.

On the other hand, it did make me wonder... the ECU needs only 1.55 mA to remember all of its settings. But my clock is taking 10.72 mA to remember the time? Maybe if the clock were actually on when the car is off (like in my dad's Capri) I could understand a draw that high. But is that seriously what the clock draws? Can someone confirm this on a working SVX?

Now I gotta go look up how to inspect the turn signal stalk. Figure I gotta take apart the steering wheel. Bah.

[Nomake Wan]

Well, I was out getting some late-night snacks for my mom, driving alone, and got to thinking. It just bugs me how... consistent the lighting outages are. All interior lights and indicators function properly. But the backlights for everything (the instruments, the shift column, the climate control and all the switches on the dash) do not illuminate when the headlights/running lights are activated.

But it's confusing me. When I switch to headlights, the clock, gear indicator and temp indicator dim as they should. The driver's window switch and the buttons on the climate control light up as they should. And the "active" lights for the switches on the dash work as they should... only the backlights are out...

Is there a good way to test if any of these lights are getting power? The problem is they're all stuck behind other things...

Grah, I guess I'll look over the wiring diagrams to see if they cover the instrument lighting...

[ItsPeteReally]

But it's confusing me. When I switch to headlights, the clock, gear indicator and temp indicator dim as they should. The driver's window switch and the buttons on the climate control light up as they should. And the "active" lights for the switches on the dash work as they should... only the backlights are out...

This may seem a silly question but .........

What effect does the panel lighting rheostat have?

[Nomake Wan]

None at--...

...

...oh my god.

As soon as I'm conscious again I'm going out there and taking apart that damn control stalk. That sounds so simple yet so obvious that it just might be it. I mean, the panel lights don't come on and the turn signals cause funky power issues. That stalk is probably what I need to peek at.

Thanks man. Can't believe I overlooked that.

[Trevor]

Originally Posted by Nomake Wan

Well, I checked those two fuses in the interior. They registered a 1.55 and 1.35 mA reading.

Please confirm that with the fuses removed, you could read a current flow in milli amps with the meter connected across the fuse holder terminals. This could be acceptable as simply leakage.

Now I'm not sure why the door lock circuit is constantly energized (especially since I don't currently have a security computer) but maybe that's a Subaru thing. As for the EGI+AT fuse, it hit me why that's drawing power. Durr, it's the ECU. The ECU has to remember what it's learned. For it to remember it needs power. Else it wouldn't forget if you leave the battery out of the car.

So I've concluded that none of the interior fuse circuits are at fault.

I took apart the dash and pulled the instrument panel. Surprising to me, only one of the bulbs in the gauge cluster looked bad. Are the bulbs in series? That would explain why every light in the cluster except for the backlights work.

No, but a common connection or ground could be open. You should check each bulb for continuity using your ohms range. Appearance will tell you nothing. Put this aside until the power loss problem is attended to.

The rear of the dash switch assemblies all looked fine. A little shocking to see that the wires are just soldered on, but all of the wires were intact and no connections were crossed. I put the dash back together.

I also tried replacing the flasher unit. All that did was alter my flash pattern, not fix the strange power loss when the turn signals come on. The wiring for the flasher unit is all intact and good too, so the flasher unit's out too.

Important question. --- Does the power loss exactly fluctuate in accordance with the flashing rate, or is it constant? You may have advised on this back there somewhere, but please confirm..

I see from back in the thread that you identified the hazard/flasher fuse and it would appear that you checked the current drain at this point. Do so again, on amps range, with the flasher and hazard functions operated in sequence and check each for for excessive current.

This circuit must be drawing a very heavy current, or is somehow causing a short against some other circuit. You have now proven that the actual flasher unit is not the culprit. As I have advised, this is a step by step process.

If you detect a high current drain, remove the flasher unit and if the current ceases, this will indicate that the drain is within a section of the wiring past the flasher unit. I hope you are getting the hang of all this by now.

Which just leaves the turn signal stalk, or wiring from the under-hood fuse box.

If there were a resistive short here, it will be registered as current flow via the hazard/flasher fuse. Don't waste your time on any direct inspection at this stage.

On the other hand, it did make me wonder... the ECU needs only 1.55 mA to remember all of its settings. But my clock is taking 10.72 mA to remember the time? Maybe if the clock were actually on when the car is off (like in my dad's Capri) I could understand a draw that high. But is that seriously what the clock draws? Can someone confirm this on a working SVX?

The clock current is of no consequence and is not extraordinary.

Now I gotta go look up how to inspect the turn signal stalk. Figure I gotta take apart the steering wheel. Bah.

You do not need to do this, see above. Look back on what you have reported and you will see that you are in fact making progress.

[Trevor]

Originally Posted by Nomake Wan

Well, I was out getting some late-night snacks for my mom, driving alone, and got to thinking. It just bugs me how... consistent the lighting outages are. All interior lights and indicators function properly. But the backlights for everything (the instruments, the shift column, the climate control and all the switches on the dash) do not illuminate when the headlights/running lights are activated.

Are the headlights/running lights operating at normal brilliance, provided the hazard/flasher system is inactive; i.e. is a severe voltage drop preventing some lamps from illuminating only when the "power loss" occurs? Please always paint the full picture.

Alternatively wiring could be messed up so that backlights do not have a proper ground and get a phantom ground via the headlights, when these are switched off. We will tackle this later.

But it's confusing me. When I switch to headlights, the clock, gear indicator and temp indicator dim as they should. The driver's window switch and the buttons on the climate control light up as they should. And the "active" lights for the switches on the dash work as they should... only the backlights are out...

Is there a good way to test if any of these lights are getting power? The problem is they're all stuck behind other things...

Grah, I guess I'll look over the wiring diagrams to see if they cover the instrument lighting...

See previous post, first things first as all could be caused by the major issue.

[Nomake Wan]

Huge post, glad I decided to check on here again... here we go...

1.) Yes, I connected the multimeter across the fuse holder terminals and registered a current flow in the mA range.

2.) Noted, but generally incandescent bulbs can tell you a lot from their appearance. Should've checked continuity with the multimeter while I had it out, but silly me forgot it had a continuity feature.

3.) The power loss is exactly when the flasher comes ON, and power returns to normal when the flasher turns OFF. However the power does not fluctuate when the Hazard switch is turned on. To further clarify:

-Move stalk to left turn signal
-Left turn signal lights come on, and at SAME TIME the dash lights and headlights dim
-Left turn signal lights turn off, and at SAME TIME the dash lights and headlights return to normal
-Repeat until turn signal stalk is returned to neutral position

I will test for current with the flasher box removed, and test current load with the flashers on (though I have a feeling it'll blow the fuse again, haha) once I get out to the car later.

4.) All right, then.

5.) Noted.

6.) Further testing will hopefully weed things out as you say, but I'm not adverse to taking out the steering wheel anyway.

7.) Yes, the headlights/running lights operate at normal brilliance provided the flashers are not engaged. "Power Loss" occurs with use of the turn signals, and only affects lamps which are actually "on." The issue of backlighting loss seems totally separate from the turn signal issue, from my point of view. Under a "normal" night operating condition (straight line driving, headlights on) there is no backlit illumination. Backlighting does not come on whether the headlights or running lights are on (i.e., putting headlight switch in running light position does not make the backlights come on, nor does using headlight position)

8.) All things could be caused by the turn signal problem. However, I do not see a relation between the manifestation of the turn signal power drain and the complete loss of all backlit illumination. They manifest independent of one another.

Further testing is in order, of many things. Time to get back out the trusty multimeter...

[Trevor]

Thanks, the numbering is a big help.

3.) Is the power loss constant when the flasher is energised via the turn signal switch, or is it a pulsing loss in sync. with the flasher rate?

If it IS constant and because all is OK when the hazard system is operating, this would indicate the fault is within the circuitry beyond the flasher unit.

6.) Depends exactly on the situation as 3 above.

7.) As 3 above, i.e. are the headlights constantly dimmed, or at the flashing rate. We will get back to the backlight issue later.

8.) All noted for later attention.

I think that, with half the world between us, we are not doing too badly.

[Nomake Wan]

I've always been a promoter of international technical assistance relations.

3.) It pulses with the flashers. It is not constant to activation of the stalk.

7.) Flashing rate.

[Nomake Wan]

Oh WOW. Trevor, once again your expertise in methodical diagnosis amazes me. I am humbled greatly. Here are the results from my latest test.

I connected the multimeter in place of the 15A Hazard fuse. With the car off, it registered 3.36 mA. I then opened the door to get access to the flasher module, but before going after it I had a thought and went back to check the multimeter. With the driver's door open, it read 7.52 mA! I then opened the passenger's door and this value raised to 11.45 mA...

Which is odd, considering that the door lights are on the Clock fuse (I assume this because when my clock fuse blew before, the dome light and door lights did not function).

Then I removed the flasher unit and closed all doors. The multimeter still read 3.36 mA with the flasher unit removed. So that means it's after the flasher unit, yes?

And here's where things get REALLY interesting. I reset my multimeter to the Amps range, then turned the ignition switch on so I could use the flashers. Activating either flasher resulted in almost NO CHANGE in the amperage. Since I'm in the Amps range, I couldn't be exact, but the change looked minute (when I initially turned on the flashers, it raised from 00.03 to 00.04, but after they were on for a bit it remained 00.03).

Then I turned the turn signals off, turned the car off... and pressed the hazard light switch. My multimeter went CRAZY! The numbers were off the scale! It couldn't even keep up with the current change, so I can't give you any number values.

So... where do we proceed from now? The short list is:

1.) Aren't the door lights on the Clock fuse? Why does opening doors cause the Hazard circuit to draw more current?

2.) Removing the flasher unit does NOT end the draw.

3.) Turn Signals do not register a current change, however the HAZARD LIGHTS register a gigantic current flow.

[Trevor]

OK --- You have now provided some interesting data to say the least, for me to analysis and this will take a little more time. Please be patient.

Something is certainly very much haywire and unusual. Digging and prodding, is not the way to go.

[Nomake Wan]

I will leave you to your thoughts before trying anything further with the car. But for thoughts, my dad had another idea.

The things causing strange draws... the doors, the hazard lights. The hazard circuit is wired into the security system, is it not? To alert arming and programming of the system? In the wiring diagram on page 10, Figure 8, segment C 28 and E 28, the hazard and parking light switches lead to fuse 23. Page 11, Figure 9, segment 35 A shows that the security system also leads to Fuse 23 (though it's listed as Fuse Block Pin D11). And the door lock system is wired into the security system as well, yes?

We're just trying to piece this together in our minds. For some reason, the door lock solenoids are constantly energized. For some reason, the hazard light circuit is drawing past the flasher unit. For some reason, opening the doors causes draws in the hazard circuit.

And for some reason, someone well before I owned the car removed the stock SVX security computer and attempted to install an aftermarket unit.

[Trevor]

It all does appear that the car has been messed up by a previous owner. Has the car always had these faults since it has been in your hands? If not, can you pin down anything at all which could have started the problems?

Silly buggers fitting after market security and audio stuff are a pain in the ass for sure.

[Nomake Wan]

I have had these problems since day one. It would appear that the previous owner either had these problems as well since his day one, or the problems occurred while it was in his possession. This is made clear by the silly little cigarette-lighter-powered lights stuck on the dash for night-time illumination of the gauge cluster which were there since I bought the car.

The radio was installed "properly" during the time I had the car. That is, it operates as it should. However, the installers did not realize how little clearance there is behind the cage, nor did they follow my instruction to use the harnesses I provided them. And so my cage is not in a proper position and cannot be adjusted without re-doing the entire install.

When I first got the car there were security components all over. Wiring, a dinky excuse for a hood release sensor, and a wireless receiver. But no computer. So I had the whole aftermarket system removed. Upon inspection, the method of removal was cutting any offending wire at its source. No wire is without insulation or shorting, but it's not as "clean" as I had hoped.

However, the problems remain unchanged before and after. No problem got worse nor better after the removal process. A few problems cleared up after I cleaned the battery and the harnesses (sticking auto belt, lack of engine power), but the serious ones remain.