Do not use more than 5 gallons of coolant.
Use same coolant as in earner. Do not use
Change coolant quickly. Allow coolant to cool
between tests. The coolant system should
have a shutoff valve (1).
Vent the coolant container (2) for air. The
coolant container may remain open or closed.
Use of a therrno-syphon type flow is allowed.
No pump is required.
Wire the heater (3) (as shown on page
1466), using the regular wiring harness.
Connect a multimeter (4) across the circuit
between the hot lead of the control box (5)
and the power source (6).
Use a fully charged battery for the power
7. Conduct the heater exhaust away from the
test area. Use an exhaust extension made of
flexible hose (7) not more than 10 feet long.
A complete test of the coolant heater con-
sists of the following:
Fuel flow test (page 14-48).
Restriction thermostat test.
Thermostatic switch test.
Combustion air blower test.
Obtaining equipment for the combustion air
blower test may be difficult. Do not do this
test if the heater burns properly and the
igniter cavity does not show undue carbon
Replace the blower if the heater goes out
during test or smokes a lot and has heavy
carbon deposits in the igniter cavity
(page 1460). Moderate carbon deposits are
normal and do not indicate a bad blower.