fuel pump wireing dia./location
Thread Starter
2nd Gear
Joined: Apr 2008
Posts: 2
Likes: 0
fuel pump wireing dia./location
Hey !
I have a 96 (dom/08/95-OBD2) I am having difficulty in getting the correct location of said relay. I have looked in the passenger compartment, under the kick panel and found a relay cluster, not the one I need to find however. I could use a wiring schematic as well. There's another cluster of relays under the hood, passenger side mounted to the back of the wheel well. (3 relays)
For some reason I keep thinking the fuel pump hot lead is purple. I was a GM dealership tech. for years and am embarrassed by this! I should know this!:
Mikey!!
I have a 96 (dom/08/95-OBD2) I am having difficulty in getting the correct location of said relay. I have looked in the passenger compartment, under the kick panel and found a relay cluster, not the one I need to find however. I could use a wiring schematic as well. There's another cluster of relays under the hood, passenger side mounted to the back of the wheel well. (3 relays)
For some reason I keep thinking the fuel pump hot lead is purple. I was a GM dealership tech. for years and am embarrassed by this! I should know this!:
Mikey!!
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Here's the schematic for a 95. I'd think 96 would be the same.
The fuel pump relay is located under the passenger side front edge of the dash. There should be 5 relays.
Relay A for the Horn
Relay B for Fuel Pump #1
Relay C Probably not used. (In 95 used for ZR1 2nd fuel pump)
Relay D for Fog Lamp
Relay E for Courtesy Lamp
Socket F empty not used
The relays on the passenger side wheel well are for the AC Clutch,
and High/Low blower speed relays if you have manual AC (C60).
The fuel pump relay is located under the passenger side front edge of the dash. There should be 5 relays.
Relay A for the Horn
Relay B for Fuel Pump #1
Relay C Probably not used. (In 95 used for ZR1 2nd fuel pump)
Relay D for Fog Lamp
Relay E for Courtesy Lamp
Socket F empty not used
The relays on the passenger side wheel well are for the AC Clutch,
and High/Low blower speed relays if you have manual AC (C60).
Thread Starter
2nd Gear
Joined: Apr 2008
Posts: 2
Likes: 0
Relays
Thanks H/V !
The diagram helped! The parts store gave me a 5 prong relay, did not match the relays in that cluster, they being 4 prong. I had swapped them out w/each other hoping that would give fuel pump activity. No luck. Now I wonder if I have a optispark problem. I know some of the GM's would shut down the fuel delivery system if the spark was lost...
Thanks again! Mikey !!
The diagram helped! The parts store gave me a 5 prong relay, did not match the relays in that cluster, they being 4 prong. I had swapped them out w/each other hoping that would give fuel pump activity. No luck. Now I wonder if I have a optispark problem. I know some of the GM's would shut down the fuel delivery system if the spark was lost...
Thanks again! Mikey !!
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
From the service manual.
When the ignition switch is turned to the On position, the PCM energizes the fuel pump relay for two seconds, causing the fuel pump to pressurize the fuel system. If the PCM does not receive ignition reference pulses (engine cranking or running) within two seconds, it shuts Off the fuel pump relay causing the fuel pump to stop.
As a backup system to the fuel pump relay, the fuel pump also can be energized by the fuel pump switch and engine oil pressure sensor. The sensor has two internal circuits. One operates the oil pressure indicator or gage in the instrument cluster and the other is a normally open switch which closes when oil pressure reaches 4 psi. If the fuel pump relay fails, the fuel pump switch and engine oil pressure sensor runs the fuel pump.
An inoperative fuel pump relay can result in long cranking times before the engine starts.
When the ignition switch is turned to the On position, the PCM energizes the fuel pump relay for two seconds, causing the fuel pump to pressurize the fuel system. If the PCM does not receive ignition reference pulses (engine cranking or running) within two seconds, it shuts Off the fuel pump relay causing the fuel pump to stop.
As a backup system to the fuel pump relay, the fuel pump also can be energized by the fuel pump switch and engine oil pressure sensor. The sensor has two internal circuits. One operates the oil pressure indicator or gage in the instrument cluster and the other is a normally open switch which closes when oil pressure reaches 4 psi. If the fuel pump relay fails, the fuel pump switch and engine oil pressure sensor runs the fuel pump.
An inoperative fuel pump relay can result in long cranking times before the engine starts.
Navigator
Joined: Mar 2009
Posts: 9
Likes: 0
Relays - Fuel pressure and Cooling fan
Here's the schematic for a 95. I'd think 96 would be the same.
The fuel pump relay is located under the passenger side front edge of the dash. There should be 5 relays.
Relay A for the Horn
Relay B for Fuel Pump #1
Relay C Probably not used. (In 95 used for ZR1 2nd fuel pump)
Relay D for Fog Lamp
Relay E for Courtesy Lamp
Socket F empty not used
The relays on the passenger side wheel well are for the AC Clutch,
and High/Low blower speed relays if you have manual AC (C60).
The fuel pump relay is located under the passenger side front edge of the dash. There should be 5 relays.
Relay A for the Horn
Relay B for Fuel Pump #1
Relay C Probably not used. (In 95 used for ZR1 2nd fuel pump)
Relay D for Fog Lamp
Relay E for Courtesy Lamp
Socket F empty not used
The relays on the passenger side wheel well are for the AC Clutch,
and High/Low blower speed relays if you have manual AC (C60).
1) I have a '94 C4 and the problem is that after replacing the opti-spark, plugs and wires it takes me several seconds of turning the engine over in order to get it to start. I was told that the fuel pressure relay is probably bad. I bought a new relay and would to replace it. I have looked under the passenger side dash and didn't see on how I could take off the panel but I did notice the fuse box and removed the cover, however I didn't see any relays. How exactly do I get to the relays?
2) I also bought a fan relay since I was told that the fan and fuel pressure relays are the same type. My fan stays on all the time, I understand it's somewhere by the driver's side head light since I don't have a shop manual I'm not exactly sure of the right location. Again please let me know on how to change it and any graphics would be great, thanks!!
