Car electrics. Anyone here any good?!

[Spectric]

Those bulbs were very common on a lot of vehicles, you just insert and rotate until you feel it lock, that is what those rectangular cutouts are for in the PCB, the bulb holder should have a corresponding raised section that sits in these cutouts and lets you know that bulb holder is correctly located.

 

[Cozzer]

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.

Power to the bulb?!
What happened to "Power to the people!"?
(Casts mind back to cr4ppy 70's TV comedy)

Sadly, the harness doesn't even allow a dangle! It can come out of its orifice by about 3", and that's yer lot as they say! Not to mention that it's facing you, and there isn't enough play to get your hand around the back to juggle things.
No...I'm afraid it would be a case of insert bulb holder, clip both connectors, push back into position, swear, pull forward, unclip, adjust bulb holder, clip connectors, push back, swear, pull forward.......you get the picture!

 

[pe2dave]

Sadly, the harness doesn't even allow a dangle! It can come out of its orifice by about 3", and that's yer lot as they say! Not to mention that it's facing you, and there isn't enough play to get your hand around the back to juggle things.
No...I'm afraid it would be a case of insert bulb holder, clip both connectors, push back into position, swear, pull forward, unclip, adjust bulb holder, clip connectors, push back, swear, pull forward.......you get the picture!

No, I'm with you, that's hard work.
Option. One of your broken bulbs? Break off the glass, so you can make contact with the leads?
With the panel on the bench, use continuity checks to work out the correct angle ( of ...)
then follow that with a real bulb.
(I'm guessing that @Spectrics suggestion hasn't worked?)

 

[Spectric]

Sadly, the harness doesn't even allow a dangle! It can come out of its orifice by about 3", and that's yer lot as they say! Not to mention that it's facing you, and there isn't enough play to get your hand around the back to juggle things.

That is a real PITA, once upon a time the wiring was longer but the speedo cable prevented you getting the cluster out and now there is no speedo cable they make the wiring shorter to ensure you still cannot get it out to far.

 

[Cozzer]

Pita.
Spot on!

 

[Cozzer]

Right, gentlemen....
I have spent most of the afternoon playing around with these ******* lights.
If I wasn't mad before, I'm probably almost there now!

Various thoughts, possibly worth mentioning, but perhaps not....

The audible alarm, if you've accidently left the lights on and have opened the driver's door. I don't recall any mention of it being a "clue"? I've tried it again this afternoon, with both side lights and headlights left on - nothing.

Spectric - you mention 5 dials. You're including the odometer rectangle as being the 5th, I assume.
That currently works. It is an oddball, I suppose, because it lights as soon as the engine fires - in other words, it's not dependent on the car lights being switched on. Whether that's important in this case, I don't know. Just thought I'd mention it.

One of the bulbs is identified as "LCD back light" on the diagrams. Yes, it's located in the middle of the unit, but it's a big area to illuminate with just a 1.4w bulb? Does it mean something else? Which leads me to something else....
The location of each dial bulb. They're all "off centre".
The tacho one, for example, is behind about 50.
The speedo is behind about 80.
The fuel and temp gauge bulbs are way off to the side.
Wouldn't you have thought they'd be more "in the middle" of the dial? Almost hidden behind the needle centre? In fact, are there LEDs in the centre of each dial, on the PCB? If so, they're not lit either!

Last query - could this be anything to do with one of the relays, either under bonnet or dash? I haven't checked any of 'em.....yet!

Hope I haven't b******d your Sunday up!
My thanks again...

 

[Spectric]

Last query - could this be anything to do with one of the relays, either under bonnet or dash? I haven't checked any of 'em.....yet!

This is where logical fault finding comes in, if you have working sidelights then the tail light relay is working and power is being sent to the cluster. The drawing shows five 1.4 Watt gauge lights on the rear diagram of the cluster and the wiring diagram also states gauge lights ( 1.4W x 5).

One of the bulbs is identified as "LCD back light" on the diagrams.

The reference to the LCD back light might be causing confusion, it is a 1.4 Watt bulb that backlights the LCD display in the speedo which shows milage and hopefully is working and not a problem.

 

[Cozzer]

Well, gents, I've given up.
I don't get it. It's obviously beyond me!
Going to give my friendly local mechanic a ring tomorrow...on his own admission he's not the world's best - "It's beyond my pay grade" - auto electric boy, but apparently is in cahoots with a good bloke in the next town. I'll try and get it booked in next week sometime.
It'll be interesting to find out what the problem is, and hopefully was - I'll let you know!

In the meantime, grateful thanks for your thoughts/guidance/time/advice.
Kudos to you.

 

[Cozzer]

Booked in for a quick shuftie on Monday morning, chaps....

 

[Spectric]

It will be something obvious, you will think how did I miss that !

 

[Cozzer]

It will be something obvious, you will think how did I miss that !

Oh, that's OK.
I'll just blame you!

 

[okeydokey]

I hope its so simple that it takes a short while and a new fuse so costs little - don't worry about "how you missed it etc"

 

[Cozzer]

The continuing ......zzzzzZZZZZzzzzzz......story...

Got the car back.
Laddo was briefed what the problem was, and what had already been done.
I even removed the panels for him - I've done it so many times now I could do it in my sleep - and left it with him.
Lunchtime, got a call from him.
He's established that power is getting to the cluster terminal, but no matter what he did from there, he couldn't solve the problem....ergo, the problem is inside the "pod".
Yes, he could contact his auto-electrician pal in the next town, but I'm looking at £50+ to "verify the same conclusion I've come to..."
It also transpires that his pal doesn't repair circuitry, but sends the unit away somewhere else.... and had I considered buying a replacement unit off eBay?

 

[Spectric]

That greatly simplifies your problem and has narrowed it right down to where the fault lies. He says the power is getting to the cluster, is it getting to the bulbs? My next line of approach would be to run a temporary ground from a known point. With just a few bulbs in place, at a missing bulb socket find the pad that is not live, this will be your ground and then hold the temporary ground on this point. If they light up then you have a broken earth and you could then do a repair by runing a new wire and bypassing the printed track.

 

[stuart little]

That greatly simplifies your problem and has narrowed it right down to where the fault lies. He says the power is getting to the cluster, is it getting to the bulbs? My next line of approach would be to run a temporary ground from a known point. With just a few bulbs in place, at a missing bulb socket find the pad that is not live, this will be your ground and then hold the temporary ground on this point. If they light up then you have a broken earth and you could then do a repair by runing a new wire and bypassing the printed track.

From my experience those 'floppy' circuit boards cause no end of trouble. Peugeot rear light clusters used to suffer problems caused by corrosion of the steel connector strips & copper? contacts of the connector blocks leadig to 'shorts'. I''ve drilled several to attach a new ground cable. I've been retired 14yrs ,so I guess things are 'different' nowadays - prob'ly for the worse!

 

[Spectric]

so I guess things are 'different' nowadays - prob'ly for the worse!

They are much worse, when it was just a connection from A to B and a switch then fault finding and repair was easily done but once you put a microcontroller into the equation with a communication bus then it takes it to another level. The wiring might be sound but a glitch in the software and the fault becomes invisible and now you need diagnostic tools to track it down. As an example a Peuguot I had would do things without any input, ie wipers come on, headlamps would not turn off and even the engine would keep running with the key removed and all because a module had an issue. Not a simple case of replace the module, the replacement module needed to have the vehicles original configuration file downloaded and the keys reprogrammed with several issues along the way, great for the main dealers to make money but not good for the customer and for something that is really just there because they can.

 

[Terry - Somerset]

In the good old days cars were hard wired. Fault finding needed no more than a bulb or a simple meter to test continuity. With a little effort almost anyone, including me, could fix faults.

In the good old days few cars had aircon, electrical seats, sat-nav, electric windows, integrated media, electronic fuel injection, central locking, multi speed wipers and fans etc etc etc. Whether all these are strictly necessary to get a ton of metal and contents from A to B is debatable.

Partly due to all this complexity we now have cars which are much safer, more economical, less polluting, more comfortable and faster than their automotive ancestors from the 1960s and 70s.

Downside - when things go wrong they can be very difficult to remedy. But typically things go wrong infrequently - in the last 15 years I have had 3 cars (1 new, 2 s/h) and covered ~250k miles during which I have had one problem related to fuel injectors (cost ~£100 to fix).

My automotive ancestors may have needed 2 engines, 5 decokes, 3 new clutches, etc etc.

On balance I will happily live with the risk of a complex electrical failure than go back in time 4 decades. This is of course no comfort to the OP!

 

[Spectric]

In the good old days few cars had aircon, electrical seats, sat-nav, electric windows, integrated media, electronic fuel injection, central locking, multi speed wipers and fans etc etc etc. Whether all these are strictly necessary to get a ton of metal and contents from A to B is debatable.

Not entirely

Partly due to all this complexity we now have cars which are much safer,

This is more like a shift in the balance of safety, yes people have more chance of surviving crashes because of airbags and crumple zones but are also more likely to have a crash through distraction caused by all those added features involving touch screens and like. When I was last recovered by the RAC the guy said that by far the biggest reason for vehicle recovery are electrical issues that cannot be readily repaired at the roadside, at times it can feel like an epidemic of failures.

We perceive cars as being less polluting, yes many are during there lifetime but not if you consider the whole product lifecycle because cars are becoming more like white goods and wheras 200,000 was common for a diesel that is fast becoming a thing of the past, my local garage has had cars with three cylinder engines that have totally failed at 70,000 so they may be clean in use but have consumed a lot of resources for a shorter lifespan.

 

[Cozzer]

That greatly simplifies your problem and has narrowed it right down to where the fault lies. He says the power is getting to the cluster, is it getting to the bulbs? My next line of approach would be to run a temporary ground from a known point. With just a few bulbs in place, at a missing bulb socket find the pad that is not live, this will be your ground and then hold the temporary ground on this point. If they light up then you have a broken earth and you could then do a repair by runing a new wire and bypassing the printed track.

Ey up, Spectric...
Didn't spot your response until now - apologies. (Gardening duties)
Hmmm.... you have more confidence in my "abilities" than I have! Hence my opening post using the Noddy level!
The still below is a freezeframe taken off a Yank video - hence the definition - and is actually off laddo's automatic, but I guess it gives a good idea as to what's going on behind mine.
I'm not sure I'd know what I'd be looking for, frankly - a loose wire would be nice, but it looks as if those days are long gone! A duff solder joint I could cope with....
So, what to do?
There are 2/3 on a certain well-known auction site, but are they going to work?
Questions, questions!

Edit : would've been a good idea to attach the image!

 

[Spectric]

This shows what bulbs are what and if you take the back off yours then tracing the tracks will be simple, I assume you have ruled out the ground being at fault! You know power is getting to the cluster and if none of the gauge lights illuminate then it has to be at a point common to all the bulbs which has to be at the connector otherwise you would only have some not working..