TRICKS OF THE TRADE
caring for our patients & ourselves
>> by thom Dick, emt-p
Warm Enough for Ya?
Preventing failures to start
“I’m melting, I’m melting!” So said the Wicked Witch of the West just before she magically
shriveled her way into history. I’m beginning to sympathize with that cranky lady.
At the time of this article’s writing, my
state has had a record-breaking summer of
wildfires after more than a month of temperatures in excess of 90° F and multiple
strings of 100-plus days in the mix. And
the calendar says our summer is still ahead.
We need rain.
One of my duties is to oversee the
maintenance of a small fleet of six Type
III Ford ambulances. They’re all 7.3-Liter
PowerStroke Diesel chassies with LifeLine
boxes. We’ve hung onto the 7.3s because
we don’t generate a lot of miles, and those
engines and their TorqShift transmissions
have been bulletproof. Just as importantly,
the quality of the boxes has supported our
continued investments in chassis maintenance. In fact, so far we’ve sent two units
back to the factory in Sumner, Iowa, to
refurbish and return them to service.
When I was originally assigned to take
care of this fleet, we were having two kinds
of starting failures. One was an easy fix:
We began replacing the batteries annually.
The other, which had plagued us for years,
was alternator failures—especially of the
upper alternators. Of course, the easiest
way to correct that would be to switch to
Type I ambulances.
One of the disadvantages of a cutaway-based Type III chassis is its teeny engine
compartment. There’s not enough room
in there for an alternator big enough to
supply the needs of an ambulance (or a
leprechaun to service it). So Ford resorted
to a pair of alternators: one mounted high
and the other one low. A Type I chassis
has a longer hood, like a pickup truck, that
offers much more space. But our garage
bays aren’t physicially deep enough to
accommodate Type I ambulances. And
Colorado’s range of temperatures can
maintaining proper vehicle temperature isn’t
rocket science, but it does require proper training.
reach 110 degrees winter to summer. So
you pretty much have to keep an ambulance garaged.
Neither of those alternators is just a
spare; if one fails (usually the upper one
because of heat), the other will follow soon
enough. You can minimize the load on
them by switching your emergency lighting from incandescent to high-intensity
LEDs. LEDs produce a lot of light with a
little energy. Decreasing the load on an
alternator should lower its operating temperature, minimize the wear on its drive
belt and improve its reliability. But LEDs
require a lot of rewiring, and that’s pricey.
You can’t just replace bulbs.
You can idle a diesel all day long,
even on a hot summer day with a
heavy electrical load (including both
air conditionings on full-blast). But
when you turn the motor off, the
radiant heat of all that metal has
nowhere to go. So your underhood tem-
peratures will rise. If the cooling system is
in good shape and your coolant is mixed at
the proper concentration, it should be OK
up to a temperature of almost 300° F. But the
underhood temperature won’t be constant.
It’ll be hottest up high (like where the upper
alternator is) and not so hot down low.
We talked to our friend Cap Unrein at
Rocky Mountain Emergency Vehicles
(EVMARS) of Denver, who does our maintenance. Cap recommended the basis of the
following hot-weather procedure. We leave
an ambulance running when we park it outdoors for just a few minutes. Nobody wants
to climb into a 120° F ambulance, right?
EVMARS installed externally accessible security switches that either lock or unlock all of
our doors simultaneously. So we can leave
a locked vehicle idling, yet we can access it
quickly for a call. Then, when we return to
quarters, we turn off the engines and leave
the hoods open.
Looks funny. Makes sense. Obviously,
we try not to leave the hoods open in public. Our crews don’t post on street corners,
and they’re mindful of the temperature-sensitive contents of their compartments, so
they normally return to quarters between
calls. And we don’t know yet if this will even
work. But it makes sense for any vehicle,
whatever its design. And in this heat, we’ve
gotta do something.
I have to tell you, there’s one more component to this plan. The crews have to understand their instruments—and the mechanics
of their vehicles—well enough to make it
work. To my way of thinking, that requires
training and experience.
Neither of which happens by magic. JEMS
Thom Dick has been involved in EMS for
41 years, 23 of them as a full-time EMT and
paramedic in San Diego County. He’s currently
the quality care coordinator for Platte Valley
Ambulance, a hospital-based 9-1-1 system in
Brighton, Colo.Co ntact him at boxcar414@