Electrical Quandary

Nomake Wan · #1 04-18-2007, 01:24 AM

Since things have somewhat come to a head lately, I figured I'd do a full update on the electrical gremlins plaguing my SVX.

First off, the battery and alternator are perfectly fine. I've checked and re-checked them and they are fine. However, if the car sits for a while (week or more) then the battery discharges. Something's drawing. I don't know what, though. It's not the power seatbelts, they work fine and I don't get the trademark clicking sound from the computer. I'm not sure what exactly is drawing.

But then today I did a full checkup on what works in the cabin and what does not.

What works:
Wipers, Climate Control, headlights, foglights, parking lights, brake lights, clock, cigarette lighter, lights in dashboard gear indicator, light on window switch, lights in climate control buttons, temperature selector lights, "on" light on cruise control, "on" light on foglights, hazard lights, turn signals, dome light, ignition light, dash warning lights, door key light, door lights, air conditioning, cruise control.

What doesn't:
"on" light on defrosters (side mirror/rear window), "on" light on parking light, "on" light on security switch, security switch, sun visor lights, instrument panel backlights, backlights for every single switch (what lights up the text on every single panel including the center console and gearshift)

I have not yet checked the wiring on the cigarette lighter or sun visors, but I suspect the sun visors most. They droop and I have a feeling they were never checked.

Just today, though, I noticed some peculiar activity. If I turn on a turn signal, all the lights in the car dim (except the clock) whenever the turn signal is on, then return to normal once the signal is off, then dim again for the next "on" in the cycle. However, if you turn on the hazard lights, this dim still happens... but it's not nearly as profound. I would think that having both sets of blinkers on would draw more power, but apparently not.

I then noticed while sitting in a drive through that my clock had gone out. I still had a response from the cigarette lighter and climate control though. When I popped the hood I found that the 10A fuse in the main fuse box for the clock was blown. Now, I had just replaced this fuse two weeks earlier (with all the other fuses) because the ones that were in the boxes were the wrong ratings.

The car is (hopefully) going under the knife today electrically, getting all of the wiring behind the dashboard inspected. There are remnants of an aftermarket security system in the car, so I highly suspect that it was not installed properly and is causing most of the problems. However, murphy's law states that removing these foreign elements will not solve the overall problem. Does anyone recognize my symptoms? If so, please help!!

ItsPeteReally · #2 04-18-2007, 02:56 AM

Quote:

Originally Posted by Nomake Wan

However, if the car sits for a while (week or more) then the battery discharges. Something's drawing. I don't know what, though. It's not the power seatbelts, they work fine and I don't get the trademark clicking sound from the computer. I'm not sure what exactly is drawing.

It doesn't have to be much, there's a 168 hours in a week, so a 200-300 mA drain will flatten your battery in about that amount of time. To narrow down the search put an ammeter in series with the negative terminal lead from the battery and the battery post. Hopefully you will see a significant current drain. If you do, pull the fuses one by one until the drain goes away (or at least seriously reduces) if you are lucky you will find one massive source of leakage and not 5 smaller ones!

Quote:

Originally Posted by Nomake Wan

Just today, though, I noticed some peculiar activity. If I turn on a turn signal, all the lights in the car dim (except the clock) whenever the turn signal is on, then return to normal once the signal is off, then dim again for the next "on" in the cycle. However, if you turn on the hazard lights, this dim still happens... but it's not nearly as profound. I would think that having both sets of blinkers on would draw more power, but apparently not.

There would appear to be a high resistance somewhere causing a voltage drop, possibly in the indicator switch itself or associated wiring, but the hazard warning system and the indicators do use separate fuses, so the problem could just be a poor contact at the fuse. Use a meter on the volts range to find where the voltage drop is occurring.

Quote:

Originally Posted by Nomake Wan

I then noticed while sitting in a drive through that my clock had gone out. I still had a response from the cigarette lighter and climate control though. When I popped the hood I found that the 10A fuse in the main fuse box for the clock was blown.

That's definitely wrong. No clock takes over 10 amps! But seeing as the clock circuit is powered all the time, I'd suspect that the aftermarket security system tapped into this supply and the additional redundant wiring is occasionally shorting out somewhere.

Nomake Wan · #3 04-18-2007, 03:00 AM

You should've seen what the wiring looked like before I had a go at the fuse boxes. Someone had removed the cover to the fuse box in the cabin so they could splice wires DIRECTLY into some fuses. I didn't note which fuses were being abused, I just yanked the wires out and replaced the fuses with new ones. This whole car has been something of a nightmare.

I'll do the meter test. I, too, hope that it'll be one massive short and not a bunch of small drains.

Thanks for the response!!

Nomake Wan · #4 04-18-2007, 04:00 PM

Well, I was right.

Getting rid of all the trashy wiring didn't solve the draw or short problems. In any event, the mess is gone and the radio cage is in. It doesn't fit. Oh well. I'll have to take a careful look at what exactly is causing my problems.

I have this sinking feeling that whatever it is that's shorting out has also blown all the bulbs that don't light, and the security module...

ensteele · #5 04-18-2007, 04:25 PM

Which bulbs don't light? Could they have just burned out?

Nomake Wan · #6 04-18-2007, 04:29 PM

It is a LOT of bulbs, ensteele. A lot.

ALL of the backlights do not work. This includes the instrument panel, and every single button on the dashboard and center console.

The only lights that DO work are most of the "ON" lights in the switches, the warning lights on the dash and the gear indicator light in the instrument panel.

SVXdc · #7 04-22-2007, 11:01 PM

It's very common for the instrument panel button illumination bulbs to burn out. On mine, I think the hazard button's bulb is the only one still working. However, all of the illumination on my A/C control buttons still seems to be working.

I seem to recall reading that another common problem is the visor wires shorting.

If you can narrow down the current draw to one or two fuses, that will definitely help point to where to look further.

Nomake Wan · #8 04-23-2007, 01:36 PM

Thanks. I already cut the visor wires (they were indeed worn out, but fixing them didn't solve my current draw problem) to rule that out.

It's just weird that the turn signals would cause such a loss of current, but I guess I never asked. Do your turn signals cause all your lights to dim?

And what else is on the turn signal circuit? The more I mess with the car, the more I think that my test method (turning on a turn signal and checking for loss of power) is in fact what's causing the phantom draw.

Thanks as always. Am finally getting this car cleaned up and fixed up. Still makes me grin whenever I drive it.

SVXdc · #9 04-24-2007, 10:16 AM

Quote:

Originally Posted by Nomake Wan

Do your turn signals cause all your lights to dim?

No. That's definitely abnormal.

Sometimes a turn signal or brake light bulb will blow and become shorted. Usually when that happens you'll see the blink rate change, though. But I'd still suggest taking a close look at all of those bulbs.

Does this happen when the engine is running, or just on battery?

Quote:

And what else is on the turn signal circuit?

Gee, I just noticed that the wiring diagrams for 92 through 95 are missing the turn signal page. Or else that circuit is cleverly hidden within another page.

Going by the 96 diagram, it looks like the output of the flasher module connects to just to the four outside turn signal bulbs and the two indicators on the dash. The flasher is powered by fuse #1 (inside).

Fuse #1 also:

Powers the back-up (reverse) lights
Is one of the supplies going into the A/T shift lock control unit

The hazard switch powers the flasher module from fuse #22 (under the hood), and bridges both the L and R side bulbs so they all flash together.

The shift lock solenoid and key lock solenoids are two good candidates for things that might be stuck 'on' and draining the battery.

Nomake Wan · #10 04-24-2007, 11:22 AM

Excellent.

As said before, the hazard lights do not cause this effect anymore. Not since I cleaned the battery tirminals and the loom connectors.

This occurs whether the car is on or not, and even happens when the revs are way above idle (3000 RPM even!!). It appears to only be the turn signals though.

The rate of flashing isn't abnormal (had that happen in the Legacy), but I haven't actually checked all four turn signals to see if they're working. I'll go do that.

I know the back-up lights work, and the systems don't dim when I put the car into reverse.

What are the "shift lock" and "key lock" solenoids? How do I test/access them? These are things I haven't checked/heard of, so as you said... it's possible they're a culprit. Either that or something in the steering stalk with the turn signal switch.

Thanks SVXdc.

angrydan · #11 04-30-2007, 10:00 PM

Correct me if I am wrong, but if the Shiftlock solenoid is stuck open, shouldn't he be able to just put the car in gear without pressing the brake pedal down? If so, that would be an easy test.

Also, on a COMPLETELY unrelated note... do your automatic seatbelts work correctly? Have any of them ever got stuck in the wrong position or behaved erratically? I believe I remember hearing that a faulty control module for the seatbelts can seriously drain batteries.

Nomake Wan · #12 04-30-2007, 10:09 PM

The seatbelts work perfectly. The track on the driver's side is dirty/busted however, and thus I have to pull the seatbelt towards the outside of the car a bit to get it to travel. But there is no erratic motion; they work when they should and work exactly like my old Legacy's autobelts (save for the whole track thing). That was my first thought, actually.

The shift lock solenoid must work fine then, because I must step on the brake to take the car out of park. You can clearly feel something thump against the shift column when working the brake.

And my key comes out of the ignition, so I guess that means my key lock solenoid works too?

Car runs okay... save for lack of lights and the turn signal thing. I don't think the battery is draining anymore, but then again I haven't been keeping an exact record of voltages and have been driving it almost daily. No problems yet with not being able to start the first time.

On the other hand I am getting an intermittent Code 21 from the ECU... check engine light comes on, goes off... comes on later, goes off... can't really seem to decide. I have a replacement water temp sensor laying around, so I guess I'll replace it and see if that fixes the problem. Or maybe it's electrical. I can't seem to pin it down to an action, though--sometimes the CE comes on from a cold start, sometimes not. Sometimes it comes on while driving, sometimes not. I can't find a commonality in the lights.

Hopefully a new instrument panel will be here sometime soon, so I can test it. I know the lights on the new panel work, so if they don't light when I hook it in, I know I really do have a serious problem on my hands. That's the only thing I can think of to test that aspect of my electrics...

d4d330 · #13 04-30-2007, 11:02 PM

Our '92 SVX will drain the battery over night if the headlight switch is left in the on position, even though the lights do go out when the key is turned fully to the off position. Perhaps that isn't correct behavior as the main idiot lights stay on all the time when driving the car. Haven't had the desire to tear into the wiring yet...

Nomake Wan · #14 04-30-2007, 11:30 PM

Interesting. I've been thinking about the possibility that my problem is in the turn signal stalk. After all, it controls light activation. And lights not working is my problem. (though the lights which do turn on work properly..)

angrydan · #15 05-01-2007, 07:06 AM

Did you mention an aftermarket stereo had been installed? (Forgive these questions if they sound basic, I'm just trying to rule a few ideas out)

If you did the stereo install, are you sure that it got connected properly for the 12v lead to the ignition and the constant 12v lead to the battery? Did you tap directly into the factory harness, or did you buy the interconnect harness that is available from members on this site? If you didn't use the interconnect harness, you may want to consider undoing your wiring and using this harness. Finally, are there fuses INLINE in your stereo's wiring? (i.e. something like a 15amp fuse installed between the stereo's harness and the factory harness)

The reason I ask about that is because I installed an after market stereo in my brother's Firebird, and the car kept blowing the fusible link. What I was not made aware of was that the stereo harness I had was NOT the original intended for that stereo and did not have an inline fuse. I installed an inline 20amp fuse and the problem never happened again. It seemed beyond me that something as simple as that could cause such a huge problem (after all, the radio DOES have its own fuse in the fuse panel)!

Anyway, it might be something worth looking at. Good luck and let us know of any new developments!