Rusty Spokes

4A0905849B is the latest and greatest switch part number..double check as i don't know what year model your Audi 80 is..but I'm sure that is the correct part number.

Same switch is used on Audi, VW and Porsche. The local VW dealer here sells them for about $32. This is a part I would get OEM..some aftermarket switches are very poor quality.




The switch on the left is an aftermarket and the right is OEM. Same part number. You can see the aftermaket switch has a hole for the return spring..old design that cracked and caused problems..the improved OEM seats the return spring internally.

RuneDams

Hi.
The car is from 1992. I'll definitely check if it is avaible for purchase near to where I live. It would be an easy fix, if it can cause a lot of different problems.
Thanks again, sincerely Rune Rasmussen.

RuneDams

I just finished cleaning the groundwire in the left of the engine room, and the ground between the battery and chassie, but it only helped some on the tone in the rear speakers, not with the warning lights. I contacted the local audi dealer, and they want almost 70$ for a new ignition switch. I've found this Tændingskontakt Fladt stik fra HERTH+BUSS ELPARTS (70513146) køb billig online though, and I'm wondering if it would be usable instead?
They also said that it would cost 320$ + spare parts, for them to take out and fix the alternator. Therefore i would try to change the ignition switch first.

By the way, is there only the 1 ground wire on the left of the engine?
Sincerely Rune Rasmussen

Rusty Spokes

Yes, one ground on the engine side and one at the battery. The switch in the link looks fine..I am shocked at the cost new from Audi for the switch. You may want to check VW and Porsche..they used the same part number on several cars too.

$320 for an alternator R+R plus parts? That seems high too. Do you have auto parts stores that will test you alternator on the car for free? Very common in the USA.

RuneDams

Clearly the american mechanics are a little more generous than the danish mechanics are. I've spoken to a few now, and they have no idea on how to test the alternator except with a multimeter, which I've already done, so my plan is now to take out the ignition switch and most likely replace it. That's a cheap and easy fix, if it helps, compared to taking out the alternator if it's not broken anyway.

RuneDams

I finally managed to remove the old ignition switch and it was indeed broken. I'm gonna start with replacing this, and hopefully the other warnings will disappear. I will reply when I've replaced the switch.
Thanks for the help Rusty Spokes, it's well appreciated !

RuneDams

I changed the ignitions switch today, but sadly it didn't make any difference with the warning lights or the charging problem. I do not know if it is just me or the cold weather, but it seemed to run a bit rougher if any. I guess my next step is to take it to the mechanic to get the alternator checked, but what about the coolant light? That shouldn't have anything to do with the alternator?
Sincerely Rune Rasmussen

RuneDams

I think I might have confused the engine lights with breakpad warning lights (i did not know it had these). It is right next to the coolant warning and essential looks like this (!). But can this light up due to the alternator not providing 14v? I just checked, and it only provides 11.5v.

danfil

On the check engine section between the gauges the lighting up of the (!) flashing on startup is normal for my '94 Cab.
As in my owners manual it is apparently checking the abs and braking system on the vehicle upon startup. If it stays on or does not flash for a period of time upon startup, something is wrong with the braking system nothing to do with the charging system.

In my experience the only way to test the alternator is with a multi-meter on the battery, before running above 12.5 volts for a good battery and around 14 volts while running less than that under load, fans on high beam lights on.

If the alternator regulator is bad ( and its probably internal or controlled by the ecu) the whole vehicles electrics are running off the battery and soon rather than later the car will stop running when the battery voltage drops from constant draining. Leaving you roadside with a dead battery unable to start again.

my 2c

Rusty Spokes

danfil makes a good point. Most of the time the voltage regulator on the back of the alternator is the problem on older alternators. The brushes wear down.

I will replace mine as a matter of maintenance at 100k miles..still have an original alternator on my 1991 Vanagon running its second voltage regulator.

I don't know if you have a Bosch alternator..if so a $35 regulator may be a solution. You don't have to remove the alternator to install..normally.

It may look like this:


Or It could look like this:





Depends on the alternator type..check it. The regulator lives behind the plastic cover on the back of the alternator.