View Full Version : Alternator Does NOT run without the Cluster

01-31-2008, 09:07 AM
OK...in diagnosing the non-working speedometer I discovered the alternator does NOT run when the instrument cluster has been removed. Not one person, including myself ever thought that would be possible...

So, basically two things happened that cost me quite a bit to get me back to square one:

The alternator does not run without the instrument cluster
Autozone did not properly test the alternator (twice = the original and the 1st new one).
Here's the cost of the lesson:

New speedo gear set = $56
New alternator = $160
Tow truck = $75
New battery = $100
Total = $391 + 1 week's worth of down time

And the speedometer still does not work.

Hey at least you now know.

01-31-2008, 07:32 PM
The car won't run above 4000 rpm without the cluster either. :mad: The speed sensor runs through the cluster.

02-01-2008, 10:35 PM
The reason for the alternator not working when the instrument cluster is disconnected might be that there is a "fail-safe" function for the charging-system alert lamp that is activated by disconnection of the instrument cluster. When the alternator fails to charge at a sufficient level, the charging-system warning lamp lights. Disconnecting that warning lamp by disconnecting the instrument cluster might also de-activate the charging system, since there is no longer a warning lamp to protect the driver from accidentally destroying the car's computers by running them outside their lower-limits for current.