Woeful Electrics

[Ben Allen 8]

As some of you know, I had a slight incident with a spanner being dropped on my battery live a while ago, earthing it. The aftermath of this was all the electrics on the car starting to go wrong one-by-one.

First of all the stereo stopped working when the headlights were turned on, indicators stopped working, and loads of other random stuff. The engine still ran fine without problems however.

 

Having decided that the wiring loom was fried, I took an entire loom from a 1.9 GTI I was breaking and got someone to fit it to the car for me. This loom included everything behind the dashboard, fusebox and the engine loom. Pretty much the only thing that wasn't changed was the loom to the back of the car to the rear lights etc.

 

Anyway, the electrics on the car are still completely and utterly sh*te. I now have no dashlights (a bit of a problem at night), when you turn the headlights on the indicators will stop working within about 5 minutes (and won't work again until the headlights are off), sometimes when pressing the brake pedal the stereo decides to reset itself, the oil temperature and fuel gauges are a little wayward at times, and also when at low speeds, the headlights are quite dim, but onec you get above about 40mph they're fine.

I just did a 1200 mile road trip in the car so the alternator and battery must be fine

 

Any ideas what the problem could be? It's turning the car into a complete nightmare

 

Cheers

[Anthony 1,003]

As I said last week Ben, I'm pretty sure that it's an earth issue of sorts, as you've got too many completely unrelated circuits playing silly-sods for it to be anything else in my opinion.

 

Biggest giveaway that there's something majorly wrong in my opinion was the fact that the radiator cooling fan was slowing right down as soon as you applied any electrical load (central locking, electric windows etc), and the power feed for that doesn't route through the fusebox

 

I'd carefully check the earth connections (particularly where it attaches to the body on the passenger side) and battery terminals and if all looks fine replace the earth cable with one from another car and go from there

[James_R 3]

As anthony says, sounds very suspect earth related, best go round all th emajor ground points clean them and put them back on.

[Phil H 16]

Stick on another alternator, as the voltage stabiliser / regulator may have been damaged during the fry up.

[Alastairh 47]

Yeah i agree, and to be honest, it can't be many more things, because you kept the same known relays anyway off that old 205 loom thats on the car now, even if that would actually make a difference in the first place.

 

Alastair

Edited August 16, 2006 by Alastairh

[Rob_the_Sparky 9]

If you dropped a spanner on the battery to earth then you would have put a huge spike down the power lines. Unlikely to take out any wiring (as all the current would go through the spanner) but likely to do damage to sensitive electronics like the alternator, ECU and radio.

 

I'd say it is quite likely that the alternaotr has taken damage - I have certainly fried every dash light in the past due to a damaged alternator regulator. Oh and it doesn't necessarily stop it charging the battery, quite possible for it to over charge...

 

As for all the rest, if you have replaced a complete loom then you have a lot of checking to do. If you have connectors on the wrong places then it can have all sorts of interesting and unpredictable results! Earths are worth a try but also just double check EVERY connection is connected to the right place and is on the correct way round, etc.

 

Rob

[pugrallye 0]

Sounds like an earthing issue, and the voltage stabiliser in the alternator issue, shorting a battery although maybe knocking out the sensitive things, would not really have caused your indicator etc to behave eratically, have seen the std power wires on 205's cause engine fires before as they are woefully inadequate and drastically depriciate after having big hot XU engines nearby them for 15- 20 years, and being as such wiring is pretty basic in them, so check and clean all your earthing points and replace that alternator

Edited August 16, 2006 by pugrallye

[Ben Allen 8]

Ah, cheers for the replies. In that case I'll fit the spare alternator I have lying around first and see if that sorts anything out.

 

The earths near the headlights in the engine bay all look ok to me, although I'm not exactly an expert. I guess if the alternator doesn't solve the problems I'll clean them all up and then continue from there.

What other earths are there I can check + where are they?

 

Cheers!

[Anthony 1,003]

If it's going to be any of the earths then I'd say it would be the main body one that provides the return to the battery for everything except the starter motor, alternator, and engine mangement (ie all the things that still work on your car). It goes from the battery terminal to just behind the battery on the side of the passenger side suspension turret, onto the ignition amp heatsink plate.

 

If that looks OK, then replace the earth wire with one from another car.

[Ben Allen 8]

Ah yes I know the one, it looks ok from what I remember so I'll grab another from the scrapyard or something later

[notamondayfan 44]

i had a simular prob last year, but not as bad as this. when ever i broke, my dash would light up, and my indicators would come on.

 

all it was in the end was the yellow earthing plug in the boot (its hidden behind inside the rear wing, behind the light cluster). ull probably have to pull the material away to get at it.

 

anyway it had just corroded a bit, so some wd40 and a clean up, and its been fine since.

 

hope that helps.

 

deano!

[pdd144c 0]

If it's going to be any of the earths then I'd say it would be the main body one that provides the return to the battery for everything except the starter motor, alternator, and engine mangement (ie all the things that still work on your car). It goes from the battery terminal to just behind the battery on the side of the passenger side suspension turret, onto the ignition amp heatsink plate.

 

If that looks OK, then replace the earth wire with one from another car.

 

Surely a quick check with a DVM for resistance will be easier?

[Rob_the_Sparky 9]

Most DVMs do not measure low enough to tell a poor earth from a good one. You can test for an open but not a poor connection.

 

Rob

[Ben Allen 8]

Ok I've just been down and changed my alternator and the battery lead over. Still no difference

[Rob_the_Sparky 9]

Ok I've just been down and changed my alternator and the battery lead over. Still no difference

 

Don't think all your problems are down to alternator. I expect that the dash bulbs will all be blown (this is what happened on my GLD years ago when the alternator regulator went). The other problems are probably down to errors/bad earths that came about when fitting the new loom (and are going to be a bitch to find).

 

Rob

[Ben Allen 8]

I did swap the clocks over previously to see if it made any difference though with a spare set and there was no change

[James_R 3]

time to get the multimeter out and start checking things mroe throughly

[Rob_the_Sparky 9]

Agreed, the long and hard method but a sure way of fixing things.

[pee vee 1]

Can anyone tell me where the main Earth points are

 

Battery to ignition amp plate is one,

 

but I was speaking to miles and he mentioned by the steering columb?

but i cant see it! lol

 

just trying to find the dodgy earth on my car!!

 

thanks!

[j_turnell 137 3 Cars]

Should be a large yellow plug on the right handside of the collumn if your sitting in the drivers seat. Whats the car doing exactly?

[pee vee 1]

the stereo cuts out sometimes if you have main beams on,

heater on and put the brakes on.

 

also, put some after market gauges in the other day,

and they seem to wander around when you turn anything electrical on!!!

 

thanks mate!

[steve@cornwall 100]

Failing batteries?

[pee vee 1]

my battery is brand new,

 

ive also replaced the earth between battery and ignition amp plate,

 

also replaced the +ve between the battery and the altenator,

just to make sure.. but it hasnt really made a huge amount of difference.!

 

will keep trying! lol

[steve@cornwall 100]

my battery is brand new,

 

ive also replaced the earth between battery and ignition amp plate,

 

also replaced the +ve between the battery and the altenator,

just to make sure.. but it hasnt really made a huge amount of difference.!

 

will keep trying! lol

 

Have you still got the original pug negative battery fixing, with the slip-on the terminal thingy? (If you know what I mean)- the prongs seem to give a pretty sh!t connection after a while

[pee vee 1]

ah right!

well im not sure if its the Original one,, but i did have a go at cleaning up the

connections just before the new battery went on!

 

these pugs and earths seem a right mystery!! lol