Posted November 24, 201410 yr comment_459167 So my mechanical fuel pump was pouring fuel into my oil. So out with that. Been wanting to upgrade to electrical for a while.Now to the nitty gritty. I know there is a T shaped female plug by the radio that you must short together to get power at the plugs by the gas tank. The problem is I'm not getting any voltage at that T shaped plug. So I'm wondering if I'm doing something wrong or there is a fuse somewhere I need to check. I wish I had a service manual for the wiring diagram. I spent a few hrs going around pretty much with no success. My car is a 71. So the 73 service manuals are the only ones I have access to. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/ Share on other sites More sharing options...
November 24, 201410 yr comment_459171 In two wiring diagrams I looked at (the one in the 1971 supplement PDF and the 1972 BE section), the wire to the fuel pump is a green wire. It should go to a 20 A inline fuse. The upstream side of the fuse comes off of the ignition switch when it is in the ON position. I don't know why you don't think you have access to the PDFs I am looking at. They are available at XenonS30 (link below). Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459171 Share on other sites More sharing options...
November 24, 201410 yr Author comment_459172 Thanks for the help. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459172 Share on other sites More sharing options...
November 24, 201410 yr comment_459173 I should add that you might consider adding an inertia switch to the circuit for safety. You can find them on ebay. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459173 Share on other sites More sharing options...
November 24, 201410 yr Author comment_459175 I'm pulling an inertia switch off a Ford tempo in the junkyard. It's about 1 dollar. Inside the trunk. I saw the wire diagram. But I'm still curious why nissan made the fuel pump circuit incomplete. I'm not sure what to do yet with that T shaped plug by the radio. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459175 Share on other sites More sharing options...
November 24, 201410 yr comment_459180 I'll let people like Alan & Carl speak up about why the fuel pump wiring is present without a fuel pump. What are the colors on the connector by the radio? Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459180 Share on other sites More sharing options...
November 24, 201410 yr Author comment_459199 The T shaped plug has a green wire going to it and a black and white wire. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459199 Share on other sites More sharing options...
November 24, 201410 yr comment_459204 The black/white wire should have 12 VDC when the ignition is in the RUN/ON position. If it is not connected to the green wire in any way, you won't get power to the fuel pump. Can you post a picture? Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459204 Share on other sites More sharing options...
November 25, 201410 yr Author comment_459222 Ok I'll post a pic Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459222 Share on other sites More sharing options...
November 25, 201410 yr Author comment_459225 Here is a pick of the said plug Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459225 Share on other sites More sharing options...
November 25, 201410 yr comment_459231 Now, have you been able to find the inline fuse? It may be that you need a female connector with the inline fuse to connect these two wires. I haven't ever traced out the actual wires myself, though. It doesn't show that connector in the 71 supplement, either. You can probably get the correct female connector from Vintage Connections. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459231 Share on other sites More sharing options...
November 26, 201410 yr Author comment_459298 I didn't find that in line fuse. But I do know that there is no power at that plug by the radio. I know I could probably tear into the dash and find the issue but I think I'd rather make my own harness. After going through the trouble with using the oem fog light harness and finding out there's almost a 2v drop from the switch to the plug, I'd hate to waste time again. Link to comment https://www.classiczcars.com/forums/topic/50486-fuel-pump-wiring-harness-s/#findComment-459298 Share on other sites More sharing options...
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