Hi All, Hoping someone can point me in the right direction.. I have an 07 LR3 with 230k and was still running on it’s original alternator. Decided to install a new alternator and battery last week because fan running non-stop. Bought a rebuilt Bosch unit and installed it, battery light appeared on dash immediately thereafter. Returned and got a second Bosch alternator and reinstalled it with a new battery today. Battery light remains on, fan still always runs. Showing code P063C. Tested Battery. 12.7V car off, 13.2V @ idle, 14.5V @2000rpm.

Now battery light still on….let car idle for 5 min, step on the gas, entire dash goes black, all gauges fall to zero, no dash lights, nada. Don’t know where to go from here. Totally stumped…any insight would be greatly appreciated. photo attached of dash before all lights and guages went dead while car still running at idle.

 

Check voltages again. 13.2 is pretty low at idle unless the engine is well heated up. How good was the 3-pin connector to the alternator?

 

Engine was warm, running for 10 min at idle when voltage between 13.2-13,6V. Tested voltage direct from alternator (where red wire connects) at 14.6V, wired new ground. Didnt check 3 PIN plug on the back of the alternator. how do i do that? Which PIN is pos/neg? Will check in the am.
thanks

 

It is not a matter of checking the connector with a meter, just want to make sure it did not break which they often do. Then they are not connected. That connector is what controls the alternator output based on signals from the ECU. It is a smart alternator, if you will. Where are you getting the 13.2 to 13.6 reading from? 14.6 is much better, a touch high but within spec when cold. And I was going to say it could be a bad ground, but you apparently covered that. I suppose it could be yet another bad alternator? I have two bad ones in a row with my old car.

 

The 3 PIN seems to be seated correctly in the alternator but I will recheck. That very well may be the issue If that is the culprit, is that 3 PIN plug wire easy to replace?
13.6 V at idle when car initially started up after install of new battery and 2nd alternator. I also had both alternators bench tested at AutoZone and both were good.
New battery tests 12.6V (car off) so I think both Alt and battery can be eliminated as the culprit.

The crazy thing is the dash lighting up with faults, then completely goes dead/black. Also heard there is a module behind the battery that can get corroded and cause dash problems also. Unlikely though because my car has been garaged its entire life, drains never clogged, never any water intrusion in the car
at all.

 

Ah... Autozone.... You want an alternator from O'Reilly Auto Parts if you have one there. They have an unusually large assortment of LR3 parts in stock and they Euro line is often OEM repackaged. Autozone is pure garbage. I myself will not rule out the alternator on this one, not yet.

The connector is what it is to replace. Cut wires, solder in spices. Not hard, not easy. There is a reason they make a repair harness though. I would inspect it carefully and make sure no pins pushed out the back.

And there is always the change the dash issue is not at all related to the alternate and battery replacement. I have chased that tail too many times, coincidences in automotive are an annoying thing, but it happens a lot.