Generac Quietpact 40G (Gasoline) / 40LP (LP Vapor) Repair Guide

**TEST 18: Try Cranking the Engine**

Discussion: If the Fuel Primer Switch is actuated but the Fuel Pump does not run, it may be due to a lack of available battery voltage.

Procedure:
Hold the Start-Stop Switch at the "START" position. The engine should crank and start. (Page 44)

Results:
* **If the engine cranks normally** but the priming function still does not work, proceed to **Test 19**. (Page 44)
* **If the engine will not crank**, refer to Section 6, Problem 6. (Page 44)
* **If the engine cranks but will not start**, refer to Section 6, Problem 7. (Page 44)
* **If the engine starts hard and runs rough**, refer to Section 6, Problem 8. (Page 44)

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**TEST 19: Test Primer Switch**

Discussion: A defective primer switch can prevent the priming function and may also prevent the engine from starting because it is in series with the Wire 14 circuit. (Page 44)

Procedure:
1. Set a VOM to read 12 VDC. Connect the positive (+) lead to the **Wire 15** terminal of the Primer Switch (leave wire connected) and the negative (-) lead to frame ground. The meter should indicate battery voltage. (Page 44)
2. Connect the positive (+) lead to the **Wire 14** terminal of the Primer Switch. Set the Start-Stop switch to "START". The engine should crank and battery voltage should be measured. (Page 44)
3. Connect the positive (+) lead to the **Wire 14A** terminal of the Primer Switch:
* With switch NOT actuated: No voltage should be indicated. (Page 44)
* Actuate switch to "PRIME": Meter should read battery voltage. (Page 44)
4. Disconnect **Connector 2** at the Fuel Pump. Connect the positive (+) lead to **Wire 14A** (Pin 2 of Connector 2) going to the Control Panel. Repeat the "PRIME" actuation test. Battery voltage should be measured. (Page 44)
5. Set VOM to "Rx1" and zero the meter. Disconnect **Wire 14** from the switch. Connect leads across the **Wire 14** and **Wire 14A** terminals. With the switch NOT actuated, the meter should read **"Continuity"**. (Page 44)

Results:
* **If battery voltage is missing at Wire 15 (Step 1):** Check **Wire 15** between the switch and the 7.5 amp fuse for an open condition. (Page 44)
* **If battery voltage is at Wire 15 but missing at Wire 14A (Step 3):** Replace the Primer Switch. (Page 44)
* **If battery voltage is missing at Wire 14 (Step 2):** Repair or replace **Wire 14** between the 4-tab Terminal Connector (TC) and the Fuel Primer Switch (SW2). (Page 44)
* **If battery voltage is at Wire 14A at the switch but missing at Connector 2 (Step 4):** Repair or replace **Wire 14A** between the switch and Fuel Pump Connector 2. (Page 44)
* **If the meter reads anything other than "Continuity" in the resistance test (Step 5):** Replace the Primer Switch. (Page 44)
* **If the Primer Switch checks good:** Proceed to **Test 20**. (Page 44)

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**TEST 20: Check Fuel Pump Operation**

Discussion: An inoperative fuel pump prevents priming and engine starting. (Page 45)

Procedure:
1. Remove and verify the Fuel Filter is not clogged; replace if necessary. (Page 45)
2. Verify fuel is available at the filter inlet. (Page 45)
3. Remove the fuel hose from the pump and place it in a container. Activate the Fuel Primer Switch. The pump should operate and fuel should flow. If it does not, proceed to electrical testing. (Page 45)
4. **Ground Test:** Disconnect **Connector 2** at the Fuel Pump. Measure resistance between **Wire No. 0** (Pin 1 of Connector 2) and frame ground. **"Continuity"** should be measured. (Page 45)
5. **Coil Test:** Connect meter leads to the **Red Wire** (Pin 2) and **Black Wire** (Pin 1) of the Fuel Pump connector. The VOM should indicate Fuel Pump coil resistance of about **29.5 kΩ**. Note that the procedure specifies maximum current draw is approximately 1.4 amperes. (Page 45)
6. **Short to Ground Test:** Connect leads to the **Red Wire** (Pin 2) and the fuel pump housing. **"Infinity"** should be measured. (Page 45)

Results:
* **No continuity in Step 4:** Repair or replace **Wire No. 0** between Connector 2 and the ground terminal. (Page 45)
* **Continuity in Step 4 but no operation in Step 3:** Replace the Fuel Pump. (Page 45)
* **Failed Coil or Short Test (Step 5 or 6):** Replace the Fuel Pump. (Page 45)

Note: Pump outlet pressure should be **2.0 to 3.5 psi**. (Page 45)

Summary Recommendation: Verify battery voltage at the Primer Switch, then confirm 29.5 kΩ coil resistance and proper ground at the Fuel Pump.