Car electrics. Anyone here any good?!

[Cozzer]

What color are these wires, hopefully one is Red/Black and the others both black.

Nope.
B15 is red/black.
B16 is red.
B6 is.....difficult to say. "Pale"* (!) with a hint of a blue band around it, as opposed to a stripe.
Unfortunately I've just had to put everything back, as I need to be going out soon....

Right...layman's description of last night coming up, in my best Noddy fashion!

To recap present situation, the only things that aren't working are the 4 dial lights, and the audible alarm if I happen to exit the car, forgetting to turn the lights off.
That's it.
It seems everything else works. All the other "warning" lights on the dash - for example the seatbelt reminder, full beam when on, indicators, handbrake et al - work. Ironically the odometer rectangle now lights... I say ironically as it was one of the 2 failed bulbs which started this whole thing off.
All exterior lights are working fine. The radio, the 12v output (aka cig lighter!) fine. The interior light comes on with the door open.

Last night I removed all the bulb holders, which leaves a hole (!) with a strip of solder, top and bottom. When you insert the bulb holder, you twist clockwise in order for the holder's copper terminals (and therefore the bulb) to connect with the strips of solder.
With the multimeter set for continuity, I checked each port, top and bottom solder, while probing the cluster's blue male socket, making a note of which pin "connected".

Each dial gave the same results - with one multimeter probe held against the "top" solder, I ran the other probe along the socket pins... B6, B15 and B16 responded.
I then switched to checking the "bottom" solder, and did the same socket pin check....same again, B6, B15, B16.

I'm not sure where all this actually gets me, but when I tell that I owned the car for 5 years before I found the secret picnic table, perhaps you'll not be surprised!

* EDIT.
The wiring colours above.... forget the "blue band" reference for B6.
In daylight, I think the blue is actually grey, but I suspect it's sort-of glue residue from the loom wrapping. It's on some other wires as well.
Comparing B6 to others, it's not white...nor is it yellow, as I can see others that claim those colours, so God knows what it is!
Incidentally, B7 right next door, is indeed black....

 

[Dibs-h]

To old, this was when vehicle electronic's had not become all encompassing. The cluster is pretty basic, old school with multiple wires and not a CAN bus which would then be a nightmare and expensive to resolve. I purchased a 2006 mark 2 CRV even though I could have got a much newer one for the same price because it uses basic wiring and not multiple modules that control everything. Old school is you operate a switch and an item receives power and works, newer technology is you operate a switch then some module decides if it is ok for that item to receive power and then may turn it on for you. All ok until a module gets a blip in the software like my last Peugeot where the body interface module decided to do it's own thing, you would even lose hazzard lights and brake lights as well as indicators which is a real safety concern, then you could not turn the engine off or operate the electric windows. This was a new module, download the vehicle configuration file then recode the keys all an expense, well no more with my Honda

I don't know much about Hondas or Japanese cars to be fair. The wife's old 2003 Fabia and all VAG cars from 2000 (at least) onwards, the immobilser was\is in the cluster and swapping means\meant recoding it & a visit to the dealer. The Fabia had nothing in the way of CanBus tho.

Much later VAG cars, even the "basic" ones started going CanBus.

 

[Spectric]

You must be very close to finding the answer, the Red/Black is the supply from the tail light relay and if you get 12 volts between this and ground then you have narrowed the problem right down. When testing that wire for live use a decent known ground such as the aux power socket.

"Each dial gave the same results - with one multimeter probe held against the "top" solder, I ran the other probe along the socket pins... B6, B15 and B16 responded."

Are you saying that the top is connected to all three, B6 B15and B16? If so then where does the bottom bulb pad connect to?

 

[Cozzer]

You must be very close to finding the answer, the Red/Black is the supply from the tail light relay and if you get 12 volts between this and ground then you have narrowed the problem right down. When testing that wire for live use a decent known ground such as the aux power socket.

"Each dial gave the same results - with one multimeter probe held against the "top" solder, I ran the other probe along the socket pins... B6, B15 and B16 responded."

Are you saying that the top is connected to all three, B6 B15and B16? If so then where does the bottom bulb pad connect to?

Ah.
Yes, I could've tried to explain better - sorry.
I checked all 10 bulb sites, but paid particular attention to the 4 dial areas.
For example, the socket nearest the fuel gauge : when the top pad was probed, pins B6 and B15 "beeped". When the bottom pad was probed, pins B6, B15 and B16 beeped.

The bulb covering the area around the tacho gave B6, B15 and B16 from the top pad, with the same result from the bottom pad : B6, 15 and 16 again.

The speedo gave top B6 and B15, same from the bottom pad.

The final dial gave top B6, 15 and 16. The bottom gave the same three.

 

[Spectric]

That sounds wrong, both sides of a bulb cannot be connected to the same pins because there is no circuit. You must be either testing incorrectly and possibly measuring via another load which is connected across live and ground so when you measure an empy bulb location it is effectively bridged by this other load giving you an incorrect result. Try putting 12 volts into the Red/Black and grounding the black but either use a current limited power supply or a 500mA fuse.

 

[Cozzer]

That sounds wrong, both sides of a bulb cannot be connected to the same pins because there is no circuit. You must be either testing incorrectly and possibly measuring via another load which is connected across live and ground so when you measure an empy bulb location it is effectively bridged by this other load giving you an incorrect result. Try putting 12 volts into the Red/Black and grounding the black but either use a current limited power supply or a 500mA fuse.

That's curious. I had the multimeter set for continuity, and measured them all the same way.
For example, the left indicator bulb gave B15 top, B11 bottom, but the right one gave B6, B15 and B16 at the top, but B12 at the bottom.
I'll try it again tomorrow in daylight.... This must be exasperating for you, so my thanks to you again. I've a feeling that the bank holiday will probably finish us both off, and I'll be searching for an auto electrician!

 

[Gerry]

That's curious. I had the multimeter set for continuity, and measured them all the same way.
For example, the left indicator bulb gave B15 top, B11 bottom, but the right one gave B6, B15 and B16 at the top, but B12 at the bottom.
I'll try it again tomorrow in daylight.... This must be exasperating for you, so my thanks to you again. I've a feeling that the bank holiday will probably finish us both off, and I'll be searching for an auto electrician!

Did you take all of the bulbs out?

Gerry

 

[Suffolk Brian]

So much of this added complication really does not benefit the customer, all they want is for the car to do what they ask of it and reliably. A lot of this has been to reduce the weight of copper used but over complexity can be detrimental to the economic repair of a vehicle, you only have to look in a local recycling centre and a lot of vehicles look very roadworthy but were deemed beyond economic repair. So what is more enviromentally freindly, a very clean car that last only ten years or one that is slightly more dirty but last for twenty years?

Weight of copper? Maybe but I don’t think so. For many years the thought has been this is simply to keep all the main dealers in highly profitable business, and shut down the independent who cannot afford all the expensive equipment or the licenses needed to run the right software.
the reason Land Rover kept the 300 tdi engine range going so long was the next generation engines were covered in electronics, and the African nations said if we cannot fix it with spanners in the middle of the jungle (with no electricity) then we ain’t going to buy it.
sorry, but this is drifting off post………..

 

[Spectric]

Weight of copper? Maybe but I don’t think so.

If you go back to the days when there was a british car industry the wiring was done in heavier gauge wire with a thicker PVC insulation, now it is what is termed thin walled hard core and they use a lot of 0.35mm. Even the heavy starter motor cables are now a smaller CSA because of the epicyclic gearbox used in the starter motor. You now can replace a bundle of wires with just a two wire CAN bus and the savings all add up. Weight is an important factor in that it helps the OEM get better MPG figures and performance whilst reducing their cost.

 

[Spectric]

This must be exasperating for you, so my thanks to you again. I've a feeling that the bank holiday will probably finish us both off, and I'll be searching for an auto electrician!

For me it is a problem that could be easily fixed if I were hands on, it is always difficult to help someone from a distance because you dont see the whole picture and having worked on electrical systems from buses / coaches to cars and HGV you can visualise the problem and fault finding process but conveying this to someone is the difficult part. Thinking about what you said regarding removing four bulbs, there are five bulbs which need to be removed.

This is what you have, five bulbs in parallel.

If you remove four and leave one in then when you measure from the top or bottom then you can still have a path to the other side via that bulb. With all removed you should then get just the two sides of the circuit with all loads open circuit..

 

[Cozzer]

For me it is a problem that could be easily fixed if I were hands on, it is always difficult to help someone from a distance because you dont see the whole picture and having worked on electrical systems from buses / coaches to cars and HGV you can visualise the problem and fault finding process but conveying this to someone is the difficult part. Thinking about what you said regarding removing four bulbs, there are five bulbs which need to be removed.

This is what you have, five bulbs in parallel.

View attachment 142413
View attachment 142414
If you remove four and leave one in then when you measure from the top or bottom then you can still have a path to the other side via that bulb. With all removed you should then get just the two sides of the circuit with all loads open circuit..

Ah.
Gotcha.
That's this evening's entertainment, then!

 

[Cozzer]

Looks as if I'm going to have to open the unit up - all the bulbs are out, and the meter is set to continuity, but the two sockets I've tried so far are giving exactly the same results as last time.
Confess I'm a bit loathe to open it to expose the board- there are 12 different clips holding front to back - and it hasn't been opened since being closed on 5 April '04!
I'm going to borrow my neighbour's smarty-pants phone to take a few shots - I'll upload later.

 

[Cozzer]

In the meantime, a couple of photo's of the unit itself, and a large one of a socket, showing what I described as a "top" and "bottom" solder strip. The red circles on the unit show the sockets which remain empty - the group of smaller sockets relates to automatic transmission, and the single socket is the cruise indicator....

 

[Spectric]

This gives some details to your picture, refering to my post in 70 with all bulbs out and no load paths between the positive supply and ground then all one side of the bulbs should be connected and terminate on one connector pin and all the other side should do the same to another connector pin.

Now on further thinking don't assume that all one side of the bulbs are the same, in other words the positive supply might be to the top of one but the bottom of another, it is just how PCB's can end up to avoid tracks crossing which they cannot.

From this picture

it shows the two pads closest to the hole may be connected by a track, my vision of this type of bulb is a plastic holder with two copper wings that make contact to the track which is not depicted by the image, a picture of your bulb holder may help and are those two pads connected or are they two tracks running parallel out of sight?

 

[Cozzer]

View attachment 142460
View attachment 142461
This gives some details to your picture, refering to my post in 70 with all bulbs out and no load paths between the positive supply and ground then all one side of the bulbs should be connected and terminate on one connector pin and all the other side should do the same to another connector pin.

Now on further thinking don't assume that all one side of the bulbs are the same, in other words the positive supply might be to the top of one but the bottom of another, it is just how PCB's can end up to avoid tracks crossing which they cannot.

From this picture View attachment 142464 it shows the two pads closest to the hole may be connected by a track, my vision of this type of bulb is a plastic holder with two copper wings that make contact to the track which is not depicted by the image, a picture of your bulb holder may help and are those two pads connected or are they two tracks running parallel out of sight?

Not the easiest thing to photograph, but your description fits very well!
As regards the pads, unsure as yet. Chickened out taking it to pieces tonight - might do tomorrow!

 

[pe2dave]

From the photo of the bottom of the bulb and the tracks, it appears as if you've about 120 degrees to get the alignment right, hence power to the bulb? I.e. if you are really careful you could short circuit the pcb with the bulb!
If this logic is right, suggest install one at a time, rotate till it lights, then move on to the next one etc.

 

[Cozzer]

From the photo of the bottom of the bulb and the tracks, it appears as if you've about 120 degrees to get the alignment right, hence power to the bulb? I.e. if you are really careful you could short circuit the pcb with the bulb!
If this logic is right, suggest install one at a time, rotate till it lights, then move on to the next one etc.

Good morning to all....
I was going to write "Christ! That'd take hours!", but seeing I've been at it for a week already....!
Mr.Spectric's #74 post is interesting - the bulbs might not be polarised, but the holders might be....

Unfortunately I'm just having to go out for a while, so am just about to put the car back together (again), so more later.....

 

[pe2dave]

Good morning to all....
I was going to write "Christ! That'd take hours!",

I don't think so. You can see the orientation of the solder blobs, just line up the bulb with those? Once you've done one, the rest should follow?
If misaligned.... Are the bulb 'contacts' long enough to bridge the gap in the solder? Wondering what that would do, blow a fuse?
(Not a very nice design IMHO)

 

[Cozzer]

I don't think so. You can see the orientation of the solder blobs, just line up the bulb with those? Once you've done one, the rest should follow?
If misaligned.... Are the bulb 'contacts' long enough to bridge the gap in the solder? Wondering what that would do, blow a fuse?
(Not a very nice design IMHO)

I just wish I could follow your idea out of the car!
The thought of wrestling with the 2 clip-in connectors umpteen times while adjusting the holder x degrees at a time.... well, it's not the job for inside the car on a hot day!
Not sure whether I mentioned this earlier, but I checked every bulb was actually working even before getting the unit out. As someone mentioned above, these things are similar to push-in Xmas lights - just 2 legs, folded up against the body base of the bulb. I managed to ease the legs out a bit with a penknife blade, and then dug out a tiny A27 battery - 1" long but 12v! - to test each one.

 

[pe2dave]

I just wish I could follow your idea out of the car!
The thought of wrestling with the 2 clip-in connectors umpteen times while adjusting the holder x degrees at a time.... well, it's not the job for inside the car on a hot day!
Not sure whether I mentioned this earlier, but I checked every bulb was actually working even before getting the unit out. As someone mentioned above, these things are similar to push-in Xmas lights - just 2 legs, folded up against the body base of the bulb. I managed to ease the legs out a bit with a penknife blade, and then dug out a tiny A27 battery - 1" long but 12v! - to test each one.

Understood. I'm not checking if the bulbs are good / duff, my thought is that (like Xmas tree lights) unless the bulb connectors line up with the socket connectors, they will not light?
*if* you can see the orientation of the socket (power to the bulb), just turn the bulb to match that orientation?
I guess you're working in the car, with the panel dangling on it's harness... agree, not fun.