Generac Power Systems IM Series - Manual (Page 15)

TROUBLESHOOTING GUIDELINES
Problem No. 1- Engine Won’t Crank
step 1- Check 15 amp Fuse F1
Test Procedure: Remove Fuse FI from generator panel
and Inspect fuse element. If necessary, use a Volt-Ohm-
Mllllammeter (VOM) to check fuse for continuity.
Test Results:-
A. Fuse FI checks GOOD: Go to Step 2
B. Fuse FI Is open: Replace Fuse FI. If engine cranks
normally STOP.
Step 2- Check Battery
Test Procedure:- Perform the following checks/tests on
the generator battery:
1. Inspect battery terminals (posts) and cables. Cable
clamps and connections must be clean and tight. Glean
and/or tighten cable clamps and connections as neces­
sary. Replace any defective cables.
2. Use an automotive type battery hydrometer to test bat­
tery STATE OF CHARGE. Follow the hydrometer
manufacturer’s instructions carefully. Write down the
specific gravity of the electrolyte fluid in each battery cell.
Write down the specific gravity reading of each cell as the
reading is taken. Return the electrolyte fluid to the cell
from which it was removed. If the hydrometer used does
not have a percentage of charge scale, compare the read­
ings obtained with the following:
SPECIFIC GRAVITY PERCENT OF CHARGE
1.260
1.230
1.200
1.170
100
%
75%
50%
25%
If necessary, use an automotive type battery charger to
recharge the battery to a 100% state of charge.
DANGER!: Storage batteries give off EXPLOSIVE
hydrogen gas while charging. Completely remove
the battery from the vehicle before attempting to
recharge It. Charge the battery only In a well venti­
lated space where explosive gases cannot accumu­
late and present the danger of explosion. Do not per­
mit smoking, open flame or sparks in the vicinity
while charging a battery._________________________
3. If the difference in specific gravity between the highest
and lowest reading cell is 0.050 (50 points) or greater, the
battery is nearing the end of its usefui life and should be
replaced. However, if the lowest reading cell has a
specific gravity of less than 1.200, recharge the battery
and then repeat the specific gravity test. If, after charg­
ing, the difference between the highest and lowest read­
ing cell is still 0.050 (50 points), replace the battery.
Test Results:-
A. Normal engine cranking occurs: STOP tests
B. Battery checks GOOD, no cranking; Go to Step 3.
Step 3- Check Starter Contactor SC
Test Procedure:- Starter Contactor operation may be
tested as follows:
1. See Figure 1. Connect the positive (+) test lead of a d-
c voltmeter to the Wire 56 terminal of the Starter Contac­
tor. Connect the meter negative (-) test lead to a clean
frame ground. The voltmeter should indicate battery vent­
age (12 volts d-c).
Test Results:
A. Battery voltage NOT indicated: Go to Step 6
B. Battery voltage was indicated: Continue test
2. Connect the positive (+) test lead of a d-c voltmeter to
the Wire 16 terminal stud of the Starter Contactor; con­
nect negative (-) test lead to a dean frame ground. Zero
volts should be indicated.
3. With d-c voltmeter still connected to the Wire 16 ter­
minal stud and frame ground, disconnect Wire 17 from its
terminal stud on Starter Contactor. Connect a jumper wire
from the Wire 17 terminal stud (on Starter Contactor) to
a clean frame ground. The d-c voltmeter should indicate
battery voltage and engine should crank.
Test Results:
A. Battery voltage GOOD and engine cranks, but will not
crank with Start/Stop Switch: Go to Step 5
B. Battery voltage GOOD, engine does NOT crank: Go
to Step 4
C. Zero battery voltage with jumper wire connected and
engine does not crank; Replace Starter Contactor SC.
Step 4- Check Starter Motor SM
Test Procedure:- Connect a jumper cable to the large
battery cable terminal stud (Wire 13) of the Starter Con­
13