Matt,
If the clicking sound you hear occurs while the prop is still turning, it
probably is the magneto impulse coupling or couplings...(some 152s have
impulse coupling on one mag, some have couplings on both mags. Either is
OK).

If the clicking happens when you cycle the LH part of the master switch, it
is the battery contactor. If the clicking happens when you rotate the
ignition switch to the "start" position, it is the starter contactor. Look
at the 152 POH Figure 7-7 for a pictorial of the electrical system to help
in the explanation.

John Severyn
KLVK

"Matt" wrote in message
...
I have a Cessna 152 with the O-235-L2C. When I don't prime enough and have
a failed start, I frequently hear a "clicking" sound from under the cowling
after I stop cranking. I think it may be coming from the battery. Is this
the battery contactor opening/closing? It does not seem to be a problem;
just wondering what the sound is.

Thanks for any help.

Matt