Expert: Roland Finston - 10/19/2011

Question
QUESTION: my 2001 LHS stopped on me and the  relays under the hood are tapping when i turn the ignition to on. So far i pulled the engine fan relay and it quieted some then the shut down relay and it got a little quieter then the a/c clutch relay and still i can here a light tapping the tapping is very fast

ANSWER: Hi Richard,
That would appear to me to be a too low voltage on the system overall due to either a failure of the alternator which allowed the battery to discharge, a failure inside the battery itself, or a short circuit somewhere in the electrical system which is drawing down the voltage overall. Relays do that when the voltage to operate them become 'marginal'.
You need to determine which is the cause, probably by using a volt-ohm meter to see if there is a short shown when you check the resistance between the + and - cable clamps after removing them from the battery and with the ignition switch in the 'run' position. If It reads less than 0.1 ohm resistance than you have short circuit that must be found and corrected.
If that is not the case, then measure the voltage on the battery with the clamps removed, it should be above 13V.
If it is, try a jump start and see, if you are successful in starting the engine, whether the charge warning light comes on.
I suspect you have a major short to ground, but it could be the alternator failed or the battery itself failed.
Roland

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QUESTION: the battery is fine tried to jump start and it did not work it still ticked but will not even turn over.

Answer
If the battery is fine, but the relays click when you turn the key to run, then I would believe that you have a short circuit somewhere in the system. You would probably find it by removing the fuses, one at a time, and then see which one when removed stops the relays from clicking. Let me know which one does the trick and we'll check that fuse's circuit.