Over charging

[hfrs2013]

Hi, I'm after some advice if anyone can help. I'm working on a 2003 75 diesel that is eating battery's due to over charging. It always starts charging at 14 (ish) volts but after about 10 seconds jumps to 20 volts. We put another alternator on it but it didn't make any difference, I've used a solus pro diagnostic and it just comes up with P1E00 CAN-bus and P1E00 Glow system. Any ideas would be greatly appreciated.

Thanks. Simon.

[DMGRS]

As far as I'm aware, it's only the alternator regulator that can affect the output - they're pre-set to a certain output voltage. Could it be a faulty batch of alternators?
I have separate regulator packs available - these replace all of the electronics responsible for voltage regulation to rule out issues there. If you fit it and find you have the same problem, I'm happy to accept returns too.
Here's the bit of kit I'm talking about:
2 Pin Regulator - CDTi Alternator (http://www.dmgrs.co.uk/collections/electrical-electronic-parts/products/rover-75-mg-zt-cdti-alternator-regulator-and-brush-kit-fits-yle000260-and-yle102500)

[trikey]

Hi Simon,

Tell John to try this: http://www.scooterhelp.com/electrics/pages/_GP200.html

[chillyphil]

Hi Simon,

Tell John to try this: http://www.scooterhelp.com/electrics/pages/_GP200.html


What?

Buy a Lambretta to tow the Rover?

:}:}:}

[Snagger]

First port of call on these motors when it comes to electrics is the plenum chamber, make sure it is not blocked , full of water and the ECU is not sitting up to its neck in it. If it is remove it and dry it out after rodding the plenum chamber. first item on top of technical help page :-

http://www.the75andztclub.co.uk/forum/showthread.php?t=125864


There is a good chance if this has not been looked at, of it being your culprit.A wet ECU can cause a thousand faults. Nothing of course to say your new alternator is not at fault.

Assuming alternator ok,

It would seem by your description that the there is a fault on the glow plug circuit, it sounds like it is permanently calling for current, and the rest of the system does not know where to throw it.

Check alternator fuse passenger side fusebox.

Like DMGRS has said in post 2, under normal circumstances it should only be the voltage regulator that determines v+ output.The only other connection from the alternator is the starter motor, before continuing to the battery +v .I don't know if a faulty starter motor could generate the extra output you are experiencing or not, but as it involves a coil and it's in the charging circuit, it may also be a factor. If it is faulty I would imagine it will be getting pretty hot.

I would disconnect the battery check all the connections from the alternator to the starter motor for tightness and integrity, and then to the battery.

WHILST THE BATTERY IS DISCONNECTED and only when, I would also remove all the multi plug connectors from the ECU and clean the them with switch cleaner .One of these block connectors feeds the glow plug relay.

The same can be done with the block connectors under the engine bay fuse board on the passenger side front wing. Again with the battery fully disconnected ,switch clean the connectors, check for damage /corrosion to the wiring bundles.




If you need to replace a voltage regulator as Matt at DMRGS has suggested post 2, here are the two different types you may find on them.


ROVER ORIGINAL ALTERNATORS ONLY, if your new alternator is aftermarket ie not Rover, these may not necessarily apply to you in this case, but may do on checking.

There are two types for the original Rover labelled Diesel alternators:-

http://www.the75andztclub.co.uk/forum/imagehosting/8178546c5ae9f0ef6.jpg

THESE ARE LAID OUT DIFFERENT TO THE 120 AMP later versions, even though the alternator bodies share the same dimensions and look the same, internally they are not.The earlier type have four connection points, two for the diode connections, two to the casing, and are usually found on the earlier 115 amp versions. On an original alternator the two looped diode ring connections are hidden beneath a blob of black silicone. On the later 120 amp version, the two diode connectors are not covered with silicone, and visible as 7mm nuts.Some of the aftermarket voltage regulators have three pins in the plug socket, but are only internally connected to two. In any event the diesel alternator plug has only two wired connections, therefore cannot be mis - connected to the alternator.


The second, later type.

http://www.the75andztclub.co.uk/forum/imagehosting/8178546c661cb89b9.jpg


has only three connection points, one to the casing, two to for the diodes.


Snagger.

[DMGRS]

I'd say around 9 out of 10 regulators I sell are the 2 pin version, as pictured below. Fresh picture off the shelf... :D :

http://i282.photobucket.com/albums/kk245/mattyprice4004/new/BF9C6F0C-FBB2-4917-ABE9-5CFA65F8E000_zpslpaoyhge.jpg~original (http://s282.photobucket.com/user/mattyprice4004/media/new/BF9C6F0C-FBB2-4917-ABE9-5CFA65F8E000_zpslpaoyhge.jpg.html)

[Snagger]

Top stuff Matt ;)

[DMGRS]

They seem to do the trick - in the colder weather we're having the originals seem to be packing up quite regularly. So far around 20 sold in November alone, but thankfully all seem to have fixed the problem. :)