Some Electrics no worky

[BIG_MVS]

Right need your help guys.

Basically after I have been messing with my exhaust I now do not have the following functioning:

Trip Computer
Radio
Lights
Central Locking
Horn

All these work:

Windows
Mirrors
Indicators
Heated Rear Screen

Not checked anything else but it starts and drives fine.

Any ideas? Earthing disturbed maybe?

I have checked fuses, battery earth. The only earth strap I have touched really is the one on the left hand rear turret which the left hand heatshield connects to.

Help

One for big JohnC I thinks .

[BIG_MVS]

Yes where is he, this is right up his alley.

Can't help thinking it's something obvious though. Just read some old threads and Juzz checked his fuses 6 times when the radio conked out.

I'll check em another 6 times tomorrow....

Right need your help guys.

Basically after I have been messing with my exhaust I now do not have the following functioning:

:

Define 'messing'

For all we know you wired it to the mains

Did you hit the alternator with it, or snag a loom somewhere, rear light loom etc..

If it's earths then it looks like it'd have to be both side earths in front of the doors as different components connect to each earth - e.g. each front light connects to the earth on the same side as the light.

Horn seems to need both - l.h earth for the relay and r.h earth for the compressor.

Really interested to see what JohnC comes up with!

[BIG_MVS]

Right need your help guys.

Basically after I have been messing with my exhaust I now do not have the following functioning:

:

Define 'messing'

For all we know you wired it to the mains

Did you hit the alternator with it, or snag a loom somewhere, rear light loom etc..

Smacked it with the hammer a few times Swapped over exhausts, then swapped back again as I couldn't get it modified to fit my downpipe

I could have caught some of the loom I suppose as the heatshield was tight to get in and out of the engine bay

Martin - if you're handy with a multimeter it might be worth checking if it's the live or earth that's broken.

Lights and horn are probably easiest to get to so I'd personally start there.

Unfortunately, I am at a disadvantage here, I only have the ccts for the Atmo. But just for clarifaction, lights, interior or head/side etc?

John - I have a set of D501 1986 diagrams - I can scan and post/pm/e-mail anything you need if it helps.

Martin - what year is your car?

[BIG_MVS]

Cheers guys.

I have the 1986 wiring diagram and was going to give it some bedtime reading.

It's the headlights that don't work. Just wondering/hoping someones else has had this before.

I could do with sorting it tomorrow as I'm booked onto a very small trackday on Wednesday. I know the car will get there and go round but don't fancy driving home with no lights on the way home.

John - I have a set of D501 1986 diagrams - I can scan and post/pm/e-mail anything you need if it helps.

Hi Simon
That would be great, I have been wondering for a while how I could get hold of a set. As there is quite a lot of them, posting them might be the best way. I`ll PM my address to you. Thanks. Unfortunately I only copied the pages for the Atmo back in 1990, never realising I would want them,
John

Hi Martin
You have a weird one here, as there is nothing common to all your faults. How any work on the exhaust, in the rear of the car, can stop the horn, for instance, from working, as it is live all the time using a different earth to the ones for the front lights, as scottydog said, and a different one again for the rear lights. That suggests to me that somewhere, I suspect in the dash, there is a brake in the 12volt supply.
How about switching the lights on and tapping (reasonably hard) around the fuse box area. Thats all I can suggest at the moment. Without the diags I am at a loss on this one
On second thoughts again while I am typing this, there is an earth M10 on the atmo, which is the earth for the horn relay, and also the headlamp relays, and door locking relays, perhaps scottydog could look in his 501 manual to find out where the earth is which is common to these relays. This at the moment this is my best bet. Over to you Simon
John
PS Just looking at my manual, I suspect that M10 is the one behind the side panel alongside the accellerator pedal.

[BIG_MVS]

Hi Martin
You have a weird one here, as there is nothing common to all your faults. How any work on the exhaust, in the rear of the car, can stop the horn, for instance, from working, as it is live all the time using a different earth to the ones for the front lights, as scottydog said, and a different one again for the rear lights. That suggests to me that somewhere, I suspect in the dash, there is a brake in the 12volt supply.
How about switching the lights on and tapping (reasonably hard) around the fuse box area. Thats all I can suggest at the moment.
John
PS Just looking at my manual, I suspect that M10 is the one behind the side panel alongside the accellerator pedal.

John you is da man!

Just went out into the garage and put the lights on full beam, gave the fuse box cover a smack and hey presto on they came. Everything else came into life as well Then it went dark again, another smack and hey back on. I'll have a good look tomorrow, maybe the burnt out fuse that has been on the car since I bought it is starting to cause problems.

Could there be a faulty relay serving all the lights, radio and horn etc?

I'll post some pics tomorrow as well.

Hi Martin
You have a weird one here, as there is nothing common to all your faults. How any work on the exhaust, in the rear of the car, can stop the horn, for instance, from working, as it is live all the time using a different earth to the ones for the front lights, as scottydog said, and a different one again for the rear lights. That suggests to me that somewhere, I suspect in the dash, there is a brake in the 12volt supply.
How about switching the lights on and tapping (reasonably hard) around the fuse box area. Thats all I can suggest at the moment.
John
PS Just looking at my manual, I suspect that M10 is the one behind the side panel alongside the accellerator pedal.

John you is da man!

Just went out into the garage and put the lights on full beam, gave the fuse box cover a smack and hey presto on they came. Everything else came into life as well Then it went dark again, another smack and hey back on. I'll have a good look tomorrow, maybe the burnt out fuse that has been on the car since I bought it is starting to cause problems.

Could there be a faulty relay serving all the lights, radio and horn etc?

I'll post some pics tomorrow as well.

As I always say 'its a feature, not a fault'..

maybe the burnt out fuse that has been on the car since I bought it is starting to cause problems.

Could there be a faulty relay serving all the lights, radio and horn etc?

Thats good news Martin

I am pretty sure that it is not a fuse or a relay, from what you have said now with thumping the area, each relay has to have a seperate earth on one side of the coil, so there will be a number of earth cables coming off these relays but they all will not go directly to the earth seperately, I am sure each of the relay earths will go to a buss bar of sorts, ie:- a junction, where they will all be connected too, with one larger cable going down to M10. I think that is where the fault lies, but I would also check M10.
Good Luck

John