[Tigers] Won't Start When Hot

Ron Fraser rfraser at bluefrog.com
Fri Aug 13 12:40:12 MDT 2010


Mark
	Basically laws of electricity; Volts = amperage X resistance.  Since
V is mostly a constant for your battery as Resistance increases you lose
amperage.   With the engine hot all metals expand and the starter can demand
more amperage to overcome that internal mechanical resistance.  Higher
Resistance in the wire slows or prevents sufficient amperage reaching the
starter.

	As Resistance increases heat at that resistance also increases and
sometimes to the point where the smoke is let out.  This is bad, sometimes
very bad.  The amperage is being consumed at the wrong position when this
happens.   The point here is that for this 12v system you want to keep
resistance between any of the connections as low as possible so you get
maximum voltage and amperage delivery to the intended point.

Ron Fraser

-----Original Message-----
From: tigers-bounces at autox.team.net [mailto:tigers-bounces at autox.team.net]
On Behalf Of CoolVT at aol.com
Sent: Friday, August 13, 2010 12:52 PM
To: tigers at autox.team.net
Subject: [Tigers] Won't Start When Hot


Thinking of the recent post where a car wouldn't start  when hot, a recent
tip in Mac's Mustang Parts reads like  this...

"Did you know that battery cables literally wear  out?  Years of
temperature extremes and exposure to toxic battery fumes  that leak from the
case
around the battery posts can cause corrosion to seep up  underneath the
insulation & wick its way up into the coper wiring. This of  course,
increases the
resistance of the cable which reduces the amount of  voltage that can travel

thru the wire to & from the  battery.

This is a very common cause of car that won't start  when the engine is hot
from being driven. If the battery cables on your  Mustang..........."

Guess I still don't understand the logic of why it  would affect the car
more when the engine is hot.

Mark L
_______________________________________________
Tigers at autox.team.net


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