Possible charging fault cause

[Pappajohn]

Originally Posted by devilmaycare

Just a thought, but was there a problem which caused you to start monitoring the battery voltage? I think your regulator is working normally and need not be a cause of concern.

recent Alternator failure and flickering lights at start-up, both with the old and new alternators.

[devilmaycare]

OK, so there is cause for concern. If you still have a problem with the new alternator (which also includes the voltage regulator) then the source probably lies elsewhere. Flickering lights have been reported by other owners (try a search), but from recollection, the fault has usually been the lights themselves.

[Pappajohn]

been on a 20 mile run tonight.

started it with everything turned off, including the heater fan.

12.4v ignition on accessory position only.
11.8v ignition on
10.2 cranking
14.8v running
14.4v headlights on (no pulsing)

drove it till hot then turned on the heater to the second lowest speed.
short delay then down to 12.2v
turned the heater off and back to 14.4/14.5v.

5 or 10 mins driving with the heater on sees the voltage creep back to 14.4v and stays there until the next cold start.

flickering lights appear to be mainly confined to dash lights...sometimes pulsing like a disco until the voltage comes back up to 14v+.

as it is charging i reckon i'll just leave alone.

[devilmaycare]

Originally Posted by Pappajohn

been on a 20 mile run tonight.

started it with everything turned off, including the heater fan.

12.4v ignition on accessory position only. Seems OK
11.8v ignition on OK - Glowplugs ON
10.2 cranking OK
14.8v running OK
14.4v headlights on (no pulsing) OK

drove it till hot then turned on the heater to the second lowest speed.
short delay then down to 12.2v Does seem odd if engine hot
turned the heater off and back to 14.4/14.5v. OK

5 or 10 mins driving with the heater on sees the voltage creep back to 14.4v and stays there until the next cold start.

flickering lights appear to be mainly confined to dash lights...sometimes pulsing like a disco until the voltage comes back up to 14v+. Sorry, I thought your problem was HIDs. Dash lights shouldn't flicker, even with low volts.

as it is charging i reckon i'll just leave alone.

The voltage swings with heater ON/OFF does look strange. I wonder whether the electric heater operation may be erratic. If you are able to check DTCs, the following relate to the cabin heater:

B10B4–CABIN HEATER 1 CONTROL
CIRCUIT LOW (FCM). . . . . . . . . . . . . . . . . .24-194
B10B5–CABIN HEATER 1 CONTROL
CIRCUIT HIGH (FCM). . . . . . . . . . . . . . . . . .24-198
B10B6–CABIN HEATER 1 CONTROL
CIRCUIT OPEN (FCM) . . . . . . . . . . . . . . . .24-202
B10B8–CABIN HEATER 2 CONTROL
CIRCUIT LOW (FCM). . . . . . . . . . . . . . . . . .24-206
B10B9–CABIN HEATER 2 CONTROL
CIRCUIT HIGH (FCM). . . . . . . . . . . . . . . . . .24-210
B10BA–CABIN HEATER 2 CONTROL
CIRCUIT OPEN (FCM) . . . . . . . . . . . . . . . .24-214

The cabin heater operation is quite complex, with three heating elements being controlled by separate modules, relays and fuses. The purpose is to modulate battery/alternator load depending on other competing requirements for power and to prioritise use. In the event of faults being identified, the Workshop Manual suggests first checking the wiring for signs of chaffing and then plugs and sockets for damaged contacts. The full diagnostic procedure looks fairly involved.

Of course, none of this explains the dash lights flicker, which may be a separate wiring/connector/control module problem. Have you checked your dimmer control for smooth operation?

[Pappajohn]

thanks for the codes.
waiting for my new OBD11 reader to arrive but i'll be checking for any existing codes, which may be quite a few i reckon.

it appears to have a realtime graph for voltage so i'll get a better idea whats happening....when i find the OBD socket that is.



dimmer switch appears ok with smooth action and positive clicks to off (bottom), full and interior light positions.

the dash lights flicker regardless of dimmer position until voltage rises to 14v+

[devilmaycare]

May be a bit of a red herring, but worth checking for codes anyway. Well, looks like you can cross the dimmer off the list. The OBD2 socket is just under the dash, driver's side. US regulations require it to be accessible from the driver's seat (I suppose it must be on the other side for them). If you get on your hands and knees, or use a mirror, you will see it. With experience (hopefully not too much) you can locate the plug by feel - having made sure its the right way round! The steering wheel tends to be a nuisance though.

[Pappajohn]

I'll find it !

my old Volvo V70 was easy...lift the centre armrest box lid, lift out the bottom cover and there it was.

I did consider pulling the three 50amp fuses tonight but it was too much work removing the cowl cover to get to the fuse box....far too cold in my garage tonight for trivial things like that.

[Simon@thecustom300cshop]

The flickering lights could just be the alternator struggling to keep the voltage up whilst the heater is on. I think pulling fuses is worth a try. Does the code reader your waiting for do more than just engine codes and running functions?

[badgx]

Can you be sure the mechanic replaced the alternator? Does it look new or just cleaned and serviced up?

Check & top up distilled water at your batteries, whilst a solution is found

[jackwalton]

Originally Posted by devilmaycare

OK, so there is cause for concern. If you still have a problem with the new alternator (which also includes the voltage regulator) then the source probably lies elsewhere. Flickering lights have been reported by other owners (try a search), but from recollection, the fault has usually been the lights themselves.

I always thought the regulator was in the Alternator too, but it appears that the ECU does the voltage regulation according to w/s manual.

Unless there is a regulator in the Alternator and the ECU does the final logic control depending upon which devices are turned on ??

Jack