Yay for electrical problems!

[LetItSnow]

FSM that I've seen doesn't offer much on where the thing is, or I'd have found it myself by now. Seems it's batched up in the cabin fusebox area. If you find it, send pictures!

[kwren]

Our svx’s are very complicated to test when we have an electrical problem for several reasons. We have little or no information and sometimes what little we have is lost in the translation.
Both our lo beam headlights function on a single relay. The hi beams also both function on a different single relay. The fog lights function on as a pair with 2 relays. Yes, 2 relays are involved to complete the circuit to only allow us to only use the fog lights when the lo beam lights are on.
The relay systems are excellent systems but hard to get to and hard to check. I doubt that a relay is the problem with the fog lights. It would be possible, for only one relay to be the problem, even though 2 are in the circuit, because the relay that works the lo beams as well as the fog lights is obviously fine and dandy if your lo beams work! Both the relays that function to control the fog lights are located to the left of the brake petals.

The combination switch at that is in the dash for fog-security-cruise, is certainly the easiest thing to start with. Like Letitsnow said yellow and white at the switch are the toggle switch wires!
To test the fog light switch, on my car, I had to know this fact. The wires that are soldered to the switch in the dash are not the same color wires as the wires on the rest of your car! At least on mine they aren’t. Where they are plugged together about a foot of wires is all you will get with “those” colors. The other side of the quick disconnect is a whole new world. On my car the wire colors on the Subaru wiring diagram are correct, but not on the actual switch just past the quick disconnect. If you haven’t already, move to the other side of the quick disconnect to do a test.
If you disconnect it there you will be able to check for continuity with your multi-meter on the ohms setting. Better with the ignition switch off. Possibly for safety for other terminals, not for this test.
If you use the disconnect the terminals to test for continuity with the fog lite depressed will be #’s 6 and 13.
Looking at the terminal block, hold it so there are 6 terminals on the top. Left to right the end one is #6.
There are 8 terminals on the bottom, so #13 would be not the farther to the right, but next to it.
(14 would be on the right at the end.)

[Trevor]

Originally Posted by ridered777

And Trevor, multimeter is the term I've been looking for . Though it would seem you mistook my statement of "When set to ammeter, it is almost no impedance, because you run the circuit "through" the instrument, that is how one measures amps." to mean that I thought there was absolutely no impedance, when I said almost. I am aware that a small amount must be produced to measure amps with - Ohms law of course. However, this amount of impedance should not affect the circuit or its operation drastically, hence the statement of "almost no".

The rest coincides with what I know, with the exception of the history lesson on previous voltmeters and "VTVM"'s .I was not aware of this, and am pleased to have acquire yet more knowledge from your seemingly limitless databases.

And as a note, my statement of "I'm just checking... if I have a voltmeters operation down wrong, then they certainly screwed up teaching me about inductors, capacitors, and transformers! " was meant to have the interpretation of that, the teachers made an error in JUDGMENT to deem myself READY to learn about aforementioned (more complex) electrical components and systems. I acquire my knowledge from a very well respected college and a more than adequate teacher- I hold no doubt the information presented was pristinely accurate.

Craig,

My post #3, was intended to answer your query:-

“Threw a voltmeter on it, and I got .2v... I'm not sure what the reading is supposed to be, but I expected to find 0v, and it would mean a wire is loose or shorting. What could be causing it to read only .2v?? Any ideas on fixing it?”

My reply:-

“It would a appear that you are using a high impedance digital instrument which will give a reading as if volts are present, due to inductance or very slight leakage. In which case take the reading as indicating no voltage on a practical basis.”

Your reply #4 :-

“As far as the type, its an older radioshack voltmeter/ammeter/impedance measurement device. I can understand negligible interference from the device if I was picking up something minute in the circuit - less than 1/10th of a volt say. But given the accuracy of the device in the past, I don't think it is the device - perhaps there is a partial short somewhere?”

My reply #6.

“I was not suggesting that there is anything wrong with your meter, but rather that you could be using a one with a high input impedance and therefore of high sensitivity, typical of a digital multi meter. If you are using a low impedance analogue instrument, this could be indicating an existing series resistance but not a short circuit to ground.”

Your reply #7, which can have no other purpose than to query my advice and was read accordingly:-

“I thought, or I was taught at least, that any voltmeter is high impedance only in a series circuit. When set to ammeter, it is almost no impedance, because you run the circuit "through" the instrument, that is how one measures amps.”

You quoted a voltmeter (Now explained as being in fact a multi meter as I had already assumed.) as being as being of HIGH impedance ONLy in a series circuit, i.e. as when being used to record current. When used to record voltage the meter is connected in parallel with the load. This opening sentence completely confused your overall statement.

As a result of text illustrating confusion, by way of sincere assistance, I went to considerable lengths to establish the true facts. However I remain in doubt as to whether even now you understand the answer provided in respect of your original question:-

“Threw a voltmeter on it, and I got .2v...” --- “ What could be causing it to read only .2v??”

N.B. For the very reasons involved, throw away the meter and use a test lamp which draws current, as a means of voltage indication.

I will pass off your last comments as simply unfortunate.

You should brush up on your English for when you are required to complete an examination paper, which requires a little more than simply ticking the pre written correct answers.

[Trevor]

Craig,

In view of the fact that the “ foglight indicator DOES light up,” the relay must be operating/closing and supplying a negative circuit to the switch assembly. (The indicator light receives a positive supply via the dimmer unit, so that full voltage may not necessarily be present at the light.)

This would indicate that the fault involves the negative circuitry from the relay to the fog lamps, or the positive supply via fuse No 4, and not the relay or the switches/circuit controlling same. All provided that the indicator light is connected correctly. You mentioned in your first post having delved in there.

You have indicated in post #4,
“Hmm. Well I inserted the (+) lead to where I disconnected the H3 bulb (positive lead from car to fog-light). I couldn't get a good negative in the socket, so I grounded it on the negative terminal of the battery”
Which I understood indicated you had no positive supply at the fog lamps.

There should be a positive supply to the lamps when ignition and all else required is switched on. Preferably use a test lamp which draws current when checking.

When the fog light switch is closed there should be a negative supply i.e. a continuity to ground. N.B. there is no permanent ground as the lamps are relay switched in the negative leg, as kwren has pointed out. This ties in with what you reported regarding your first test attempt. Again best to use a test lamp to battery. If not continuity and the lowest ohms scale and expect two or three ohms resistance in the wiring and switches. Hence the preference for a test lamp drawing current.

You must establish these two tests as being accurate. Surely from then on the path to trace the faulty circuit will be obvious.

I trust that you will now be fully aware as to my exact interest in your method of testing and the issue of impedance in respect of your original test and post.

[LetItSnow]

Originally Posted by kwren

Both our lo beam headlights function on a single relay. The hi beams also both function on a different single relay. The fog lights function on as a pair with 2 relays. Yes, 2 relays are involved to complete the circuit to only allow us to only use the fog lights when the lo beam lights are on.

Yow, that could be misleading.

The first relay that influences the fog lamps' functioning is the left headlamp relay. This is technically part of a separate circuit; I don't see that it should be counted in this fashion, kind of like counting your state when describing your apartment.

The second relay only indirectly allows the fogs to light. Whether the headlamps are on, whether the HI/LO switch is set to LO, and whether the fog switch is on are the real culprits. Removing the HI/LO switch from the circuit would allow them to be on when the hi-beams are on, and switching the +12 source from the headlamps to the marker lights would allow them to be on when any lights were on.

[kwren]

Quote:
Originally Posted by kwren View Post
Both our lo beam headlights function on a single relay. The hi beams also both function on a different single relay. The fog lights function on as a pair with 2 relays. Yes, 2 relays are involved to complete the circuit to only allow us to only use the fog lights when the lo beam lights are on.

Quote from LetItSnow:

Yow, that could be misleading
The first relay that influences the fog lamps' functioning is the left headlamp relay. This is technically part of a separate circuit; I don't see that it should be counted in this fashion, kind of like counting your state when describing your apartment.

The second relay only indirectly allows the fogs to light. Whether the headlamps are on, whether the HI/LO switch is set to LO, and whether the fog switch is on are the real culprits.

if a main component in a circuit that will not function with it can be referred to as "indirectly", then so be it. If you bothered to use my complete quote, i stated that in this case it wasn't relevant. Hope you weren't offended by my saying you were right about the yellow and white wires on the fog light switch?? Of course you were!

More LetItSnow quote
Removing the HI/LO switch from the circuit would allow them to be on when the hi-beams are on, and switching the +12 source from the headlamps to the marker lights would allow them to be on when any lights were on.

Your quest switch a 12 volt power supply from the headlamps to the marker lights is already covered. the hi and lo beam head lights, the fog lights, the marker lights, brake lights, etc already have the 12 volts necessary to cause them to function applied when the ignition switch is turned on... some before.
They are ALL just waiting for the relay circuit to be provided a ground to make it close to provide a ground for the actual light. The 12 volts is just sitting in the lamps waiting! In them all, even the fog lights!!

It would be necessary to know about the 2 relays in the fog light circuit on the rare occasion that you needed to completely trace the circuit and the component that you classify as "indirectly allows the component to work" happened to have a wire color change when the circuit goes through that component. Actually, the wire colors do change in this situation. tracing a complete circuit is easier if you know both where it goes, and where it goes from there.

Please don't start a war with this. My subject line says I was just trying to help, which is always the case.

Keith

Ohhhhh, about this remark............
"kind of like counting your state when describing your apartment."
You know a lot about me LetItSnow. I consider my home... not my state... but my world!!
Take care
_______

[LetItSnow]

No war implied nor intended... I was aiming for clarity, not correction. See you at the next color question.

[Trevor]

Originally Posted by LetItSnow

Yow, that could be misleading.

The first relay that influences the fog lamps' functioning is the left headlamp relay. This is technically part of a separate circuit; I don't see that it should be counted in this fashion, kind of like counting your state when describing your apartment.

The second relay only indirectly allows the fogs to light. Whether the headlamps are on, whether the HI/LO switch is set to LO, and whether the fog switch is on are the real culprits. Removing the HI/LO switch from the circuit would allow them to be on when the hi-beams are on, and switching the +12 source from the headlamps to the marker lights would allow them to be on when any lights were on.

Unfortunately also misleading and is incorrect.

There are two headlamp relays in the main distribution system. One for left and one for right, so as to provide twin fused positive circuits by way of security. Both relays become energised and closed when the ignition switch is in the accessory position, (positive leg.) and the lighting switch selects head lamps, (negative leg).

There is a third headlamp relay controlled in the negative leg by the dimmer switch. This relay switches the negative supply leg of both high beams, both low beams being permanently grounded. The dimmer switch also provides an interlock which allows the fogs to illuminate only in the dim position.

As kwren has noted, the circuitry is overly complicated and in fact involves some very poor electrical engineering particularly in the use of negative switching. A lady horse of the night.

[LetItSnow]

Apologies, I left out any mention of the high beam relay and right side headlamp relay, but I found them to be outside of our scope, and thus not worth mentioning... AFAIK, neither of them should have any effect on the operation of the fog lamps, but that's drifting from the topic.

Too much text, too few schematics.

[ridered777]

Wow. Well the biggest thing you guys have all helped me to come to understand is that there is no way I can solve this one - just getting to all those relays won't be happening till spring. And even then, I doubt I can track down the problem.

This circuit is very complex, and certainly over my head. I'll just need to try and find someone who knows about this stuff who isn't too far away to try and help.

Thanks a million for all the info guys - I'll probably be printing this thread out for reference down the road, a ton of good information in here.



Oh and Trevor, my English, and subsequent semantics, are not up to par - I've never had a theory or lab circuits test that involved anything other than multiple choice and possibly a drawing or two! Just about everything is multiple choice, to be selected after several calculations.

[kwren]

Originally Posted by LetItSnow

Apologies, I left out any mention of the high beam relay and right side headlamp relay, but I found them to be outside of our scope, and thus not worth mentioning... AFAIK, neither of them should have any effect on the operation of the fog lamps, but that's drifting from the topic.

This is true... the drifting thing that is!... the main headlight relays are a part of an interesting and complicated system, but as Trevor also pointed out, the fog lights get their power from an independent fused source that is not related to the headlight relays. I thought it was also interesting that their those fog lights are only fused and the 12 volts are at the fog lights even with the ignition switch off. It is ok, but just a bit interesting to me.

For our friend that is trying to make the fog lights work, don't give up.
You will probably end up finding that through all the maze of "interesting information" there will be a simple solution to the problem. Seriously, there are but a few possibilities!

Too much text, too few schematics.

Check the attachment please for "a bunch of schematics" for anyone that doesn't already have this information.

Take care,
Keith

[kwren]

Originally Posted by ridered777

Question for the electrically inclined on the board....

I had a blown fog light, so I replaced them. Just before replacing them, I pulled the switch panel that has the fog-light switch among other things... This was in late fall. I wanted to see if I could get at the bulbs in there, the little green ones, you know.

Well anyway, since doing those aforementioned things, my fog-lights don't want to work. Pulled the new bulbs to check the filament, and they look fine. Threw a voltmeter on it, and I got .2v... I'm not sure what the reading is supposed to be, but I expected to find 0v, and it would mean a wire is loose or shorting. What could be causing it to read only .2v?? Any ideas on fixing it?

Its not pertinent... it's just bugging me, and when I have a warm day I want to go out and tinker with it. I was hoping someone might have experience a similar problem...?

If you check the fog lights for voltage from the connectors on the filaments to ground and do not get 12 volts with your fog light switch on the dash off, you probably have a blown fuse.
reason.......... there is always a 12 volt supply to the fog lights, even with the ignition switch off.
Don't give up on this thing!!
Keith

[Trevor]

Originally Posted by ridered777

Wow. Well the biggest thing you guys have all helped me to come to understand is that there is no way I can solve this one - just getting to all those relays won't be happening till spring. And even then, I doubt I can track down the problem.

This circuit is very complex, and certainly over my head. I'll just need to try and find someone who knows about this stuff who isn't too far away to try and help.

Thanks a million for all the info guys - I'll probably be printing this thread out for reference down the road, a ton of good information in here.

Oh and Trevor, my English, and subsequent semantics, are not up to par - I've never had a theory or lab circuits test that involved anything other than multiple choice and possibly a drawing or two! Just about everything is multiple choice, to be selected after several calculations.

Craig,

I and I am sure others, are disappointed that you have chickened out. A lot of time and effort has been expended by several members in providing you with clear information.

As I have shown after much research, the fault appears to be beyond the point of relay control. You have claimed expertise and have been shown how the first basic testing does not require accessing any relays, but have reached for the too hard basket.

I am finding that many find it easy to post a query. without much thought or effort, expecting others to do their donkey work. Refer sticky heading this section.

I am now becoming much less inclined to offer assistance, particularly as very often money is later shown as not being a problem.

[Trevor]

Originally Posted by kwren

Check the attachment please for "a bunch of schematics" for anyone that doesn't already have this information.

Take care,
Keith

Thanks a million Keith,

I have the official electrical section of the US SVX Subaru manuals, kindly mailed by a member here. The wiring diagrams are in a different format and alarmingly in actual substance. The relay arrangements are quite different.

I have printed yours out for future reference. As a matter of interest, where were they published?

You will recall that there was confusion within another thread and it was shown that the actual hardware is often at odds with the diagrams. On this one we are clearly up the creak with no paddle is sight.

[ridered777]

Originally Posted by kwren

If you check the fog lights for voltage from the connectors on the filaments to ground and do not get 12 volts with your fog light switch on the dash off, you probably have a blown fuse.
reason.......... there is always a 12 volt supply to the fog lights, even with the ignition switch off.
Don't give up on this thing!!
Keith

Keith, I will check the fuses, that I know I can do.

Trevor, I states in my original post that it "is just bugging me, so I thought I would weight some ideas". I made no false statments about spending countless hours hunting down this electrical bug - they're just foglights for crying out loud. I really wanted to fix them, because I want to swap them over to HID's to match the low-beams. I will quote my original post "Its not pertinent... it's just bugging me, and when I have a warm day I want to go out and tinker with it. I was hoping someone might have experiance a similar problem...?".

You have yourself commented several times in this thread on my general incompetence regarding electrical components and terminology. I never claimed any expertise in this field - if I felt I was an expert, I would not have asked anyone else's help!

I'm sorry if I make people feel cast-aside with my decision, but I already know that this electrical system is way over my head - I like working on the old 60's cars, before even EFI, I can do that kind of electronics. Looking at the wiring diagram for this car makes my head spin, I have but one year of Electrical Engineering at the college level, under my belt.

I will check the fuses tomorrow when I have sunlight, thanks for the tip. Unfortunately, I think the problem might be deeper - If I had a blown fuse, wouldn't the "indicator" light not light up on the switch? It is certainly worth a shot. I will also keep my eyes out for things that could be ary with the system. But if it is this in-depth, I am not ripping apart the interior of my only car to track down an issue with the foglights - perhaps when I do the 5spd swap in the summer.