Electrical gremiln

[stonesie]

ok i dunno the fuse number but the front o/s sidelamp and rear sidelamp, plate lights, dash lights and heater controle lamps all run off it and the damn thing blows as soon as the lights are turned on.

That tells me its earthing out somwhere but i havent got a clue where to start looking, my dad eaven says it could be a faulty bulb

all ideas are welcom

cheers matt

[Brianmoooore]

Fuse is 23. Theres a feed from this circuit to the radio connector. Because of the way this loom gets molested , this is the first place I would check, followed by the front and rear ashtray lamps.
The panel lights etc wire is grey/red and the external lights wire is grey/white.

[stonesie]

Cheers Brian, checked all that and its still not having it.... radio works fine though.

The to-do list is as long as my arm and growing

I have had a multimeter at it and the grey/white wire at the sidelamp bulb has continuity to the chassis with everything off so the front pannal is gonna come back off and see if the loom has been rubbing anything... its not so much a learning curve as a vertical slope.

Expect a few more daft questions, the mechanical parts i can do but no good with the electrics

[Brianmoooore]

Right, best way to go from here, I think, is to connect a wire to the battery + to a 5A fuse, to another piece of wire, and to then connect the free end of that wire, with the main lighting switch off, to the grey/red wire of the instrument light circuit. This is easiest to access at the rear ash tray lamp.
The panel lights should either all light or the 5A fuse should blow.
Next, connect the wire to the grey/white wire and see if the fuse blows or the sidelights and number plate lights come on.
Just had another idea - what happens if you use the right hand parking light function on the indicator switch?

[stonesie]

Right brian i have just got back from the parts shop with a fist full of 5 & 7.5A fuses and a length of wire.... tried grey/red in the ashtray and it blew the fuse straight away so i measured it's resistance to ground at about 830 ohms

on the grey/white it was the same story but only 2 ohms resistance to ground so i am thinking that i have routed the loom wrongly when i re fitted it, the cars had 2 new wings and new front pannal + welding on the front inner arches so the wireing loom was removed back to the n/s turret.

[stonesie]

Slight update, after stripping and rebuilding the front end its nothing to do with the grey/white wire... but i did take the oppertunity to re-rout the loom and wrap it in a good layer of insulation tape (yellow/green stripes... very fetching )

and after wrestling the plug from the light switch i connected the grey/white to the battery + with fuse as brianmooore said, and the o/s sidelamps came on front and rear

Tried the same on the grey/red and pop went the fuse

This car is officially getting on my nerves now, but at least its getting somwhere

[Brianmoooore]

So you now know the problem's with the instrument/dash/ash tray lights.
Pull the 4 pin radio plug from the accessories socket at the back of the glovebox, and try again.

[gazjon]

A few surgestions that might help:

Try adjusting/disconnecting the dash light dimmer switch, these are variable resistors and it common that the contacts can short out .

Check that the heater control cables are not rubbing on the loom, if they are still to opperate this could indicate something getting trapped on them.

Hope this helps

[Brianmoooore]

A few surgestions that might help:

Try adjusting/disconnecting the dash light dimmer switch, these are variable resistors and it common that the contacts can short out .

Check that the heater control cables are not rubbing on the loom, if they are still to opperate this could indicate something getting trapped on them.

Hope this helps

Dimmer switch is in the "earth" circuit of the panel lamps, so a short to earth here would only make the lamps light at full brightness.
Heater controls could well be involved in the problem though.

[gazjon]

I am aware of this but having worked on many vehicles, with either negative/positive or isolated earth return systems, I have found many a dimmer switch to cause some very strange faults. However in fairness my wording does say short, prehaps an abnormal resistance would be more appropriate

[stonesie]

cheers

Plenty to be getting on with tomorrow night, i will try to beg my bosses multimeter again to check all the bulbs (a couple don't work so will be replaced), new throttle body gasket should be here too so will get that changed and swap the tps....

Starting to think the guy who sold me this had exceptional timeing

[stonesie]

Cheers for the help to Brianmooore and gaxjon

its sorted now, the radio's earth was connected to the grey/red and the brown earth wire was cut off right at the loom so thats sorted now but leavs me wondering how long its been like this and why it didnt cause a problem before