Hand Brake, Brake Fluid & Battery Warning Lamps Glowing

[rallye_turtle]

Hi Guys,

Pretty much as the title states really. When I turn the ignition on all warning lights on the intrument cluster come on as they should, and once the engine has started they all go out, appart from the hand brake, brake fluid and battery warning lights which glow faintly (these are brighter at ignition). I've done the following checks:-

- Checked voltage across battery whilst engine running which was 12.54v and when revved over 2k the voltage graduates from 13v up to 14.5v.

- checked and replaced voltage regulator pack as a precuationary measure, but made no difference.

so appart fom the above, is there anything else I can check, ie any wires from the back of the instrument cluster.

Any help would be much appreciated.

Cheers

Wayne

[rallye_turtle]

Any ideas?

[rallye_turtle]

Ok, just been hunting round on the forum for a similar prob and found this post:-

http://www.e30zone.net/modules.php?name ... alternator

It mentions about the blue wire from the alternator. My question is does this blue wire provide a positive feed from the alternator to the intrument cluster in order to turn the Battery warning lamp off once the engine is started. I disconnected the blue wire from the alternator and done an end to end continuity test, the other end being on the blue wire on the blue plug behind the instrument cluster. there was continutiy there, but what i found was the if I left one test lead connected to the blue wire and touched the other test lead to ground it would give continuity to ground. I'm guessing maybe that the blue wire has a break somewhere and is earthing, or is this wire supposed to be earthed, not really sure ?????

[jbh]

im sure our resident guru my moorrre will be along soon to keep you right but have you tried what it says to do in the post you linked to ?

[rallye_turtle]

Yup, did the voltage test from the alternator casing to an earth and it gives 0.2v, not sure what this indicates (bad alternator earth perhaps). Have replaced the regulator pack with a brand new bosch item which hasn't made any difference either, infact the warning lamps seem to glow slightly brighter now. In addition the ABS lamp comes on when the revs drop below 1k, if I rev the engine the light goes out but comes on again when the revs decrease to say 700rpm.

[rmt]

This sounds like the same problem I had recently. It turned out the slip rings (where the brushes on the regualtor touch the alternator) had worn too much for a new regulator to do any good. I bought a recon alternator and this solved the problem. Alternatively you could look for a good secondhand alternator and put your new regulator in it.

[Brianmoooore]

Yup, did the voltage test from the alternator casing to an earth and it gives 0.2v,

Voltage measured depends on the current flowing at the time, but that sounds enough to prompt an investigation into the alternator earthing arrangements.
I tend to agree with rmt - most alternator problems can be cured by changing the brush pack, but not all, unfortunately.
The other possibility is the electronics on the SI board playing around, but I doubt it.

[rallye_turtle]

Cheers for the reply guys. Ok, I've bin prodding around the car this morning and checked the following:-

- Removed the alternator, inspected the slip rings which have slight wear but appears to be ok and was able to confirm that the brushes on the regulator do make tensioned contact with the them.

- The connection post on the back of the alternator, which connects with the blue wire makes continuity with the outer casing of the alternator, is this correct???? If this is true then what is this telling the instrument cluster (as this wire connects to the charge lamp)

- Checked the voltage from the green wire (The one that is seperate from the blue and white harness plugs) on the back of the instrument cluster and I'm getting 11.84v (would of thought this would have been 12v), however, when measuring voltage directly across the battery I'm getting 12.05v, strange. Haynes indicates that this wire comes from the ignition switch.

- Did a voltage check while the engine was running fom the positive post on the engine bulk head and the earth point on the suspension turret and I'm now getting 11.88v, however, when I rev the engine past 1.5k the voltage rises to approx 13.2v. Does this warrant an alternator issue????????????????

I love tinkering around with the car to try and fix faults but bloody hell its getting difficult with the cold weather



From the above what do you reckon guys.

[Brianmoooore]

All your measured voltages are low, so IF the alternator is earthing correctly, you have an alternator fault. Probably one of the three phases gone down.
An oscilloscope on the output would show this up.

[rallye_turtle]

you have an alternator fault. Probably one of the three phases gone down.
An oscilloscope on the output would show this up.

Mr Moooore you're absolutley right , I spoke to an alternator company who stated exactly what you said when I mentioned the symptoms I was experiencing with the car. He mentioned about how one of the phases could be faulty hence the low voltage at idle, and also that depending on the position of the alternator winding when the engine has stopped then this can cause the battery to discharge should one of the phase diodes be faulty. I guess from the latter will expalin why my battery went flat the other day which was quite strange considering it was fine previously, it was just down to luck as to where the alternator windings stop when the engine is turned off.

I'm going to get another alternator to see if this sorts the issue out.

[rallye_turtle]

fixed At last!!!!!!!

Managed to sort this annoying problem. It did turn out to be the alternator. Bought a brand new alternator, fitted it and now all warning lights go out after the engine is started, instead of that annoying red glow that i used to get. Car seems to feel a bit more perky to drive, not sure if thats the car or me just feeling happy that the issue is now sorted. It would seem that if the dash warning lights start to glow faintly then it is an indication that one or more of the diodes inside the alternator are on there way out (read it on some alternator site). Just glad its now fixed.

cheers for the replys chaps.


Wayne