Electrical minded Volks:

Yesterday I put a volt meter on my auxiliary battery:
Key off... voltage 13.2
Key on... no effect... voltage 13.2
Ignition... the voltage dropped to 12.6 during start up.
Engine running.... the voltage went up to 14 volts.

A Bosch 75 amp relay is installed between the aux batt and the starter batt.
I used #4 wire between the batteries and the original fridge relay actuator
wires that are supposed to be controlled by the D+ post on the alternator, I
think.

The whole ignition/starting process took only about 1/2 second so this was
pretty bang band... It was hard to notice exactly when the voltage dropped
in the process... before, during or after the first millisecond of the
engine
turning over. But I can't think of any way the auxiliary battery would show
a
voltage drop unless it was involved in feeding the starter.

So, my question is:
Is it normal for the stock fridge relay actuator wires to get hot while the
starter is working and drawing from the starter batter?
If not, what are the likely reasons that mine is doing so?

Bill