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1986 720 FP relay wiring


izzo

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Anyone have the relay wiring diagram. its a six plug connector into a relay. it just stops working at random, even replaced it. same thing. fuel pump was replaced too, so i am going to wire in a bosch relay instead of the 75 nissan one..

 

Need this asap if anyone could help

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Anyone have the relay wiring diagram. its a six plug connector into a relay. it just stops working at random, even replaced it. same thing. fuel pump was replaced too, so i am going to wire in a bosch relay instead of the 75 nissan one..

 

Need this asap if anyone could help

 

Does the nissan relay have the pin numbers on it. It should as bosch standardized relay pin numbers.

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It works most of the time. Shuts off a while and u don't hear the fuel pump. Then later it works again. Relay got replaced and it's been fine but started doing it again.

 

I caught the diagram thanks man. Think I will still wire in something else to the fuel pump. I am not getting stranded again and spending 100 bucks to tow it home

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The Nissan relays are ultra-dependable, better than Bosch. Just make sure its genuine, they say JIDECO on them.

 

The wiring for the pump includes TWO relays, with safety features so it is tied into the alternator and oil pressure switch. So make sure they are working fine as well.

 

You could of course rewire for single relay triggered by IGN, but that is less safe in an accident.

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Hmm. I know the oil pressure switch is half assed. Sometimes the oil light comes on even tho pressure reads half half way on gauge 45 lbs. And sometimes the pressure switch reads zero but I checked it and the oil pressure is fine. Maybe ill see about replacing the oil pressure switch but like I said I dont want to get stranded.

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Yes, a flaky oil switch will cause problems. The sender is a dual-type the oil gauge part, and the low-pressure sensor part, only the low-pressure part is involved with the fuel pump.

 

You could bypass the Nissan stuff and do this with an oil sender from Holley or Mr. Gasket with a standard Nissan C9900 EFI/Fuel pump relay:

22115.jpg

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F&*^ing previous owner rewireing shit like this in.

 

Why in the world would you even consider not fixing the problem that is causing this.

 

If I ever sell my car, I plan on giving them a wiring diagram which is current with the state of the car.

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F&*^ing previous owner rewireing shit like this in.

 

Why in the world would you even consider not fixing the problem that is causing this.

 

 

I don't know what is causing it. And neither do the previous two owners. The original owner couldn't figure it out, the guy before me dicked with it for a week and couldn't figure it out. Even did a motor swap. Problem still exists. Now, when I said i wanted to wire in a different relay. I didn't quite understand how this worked. Now I have more information. I think what I will do instead of unplugging the original relay, and using spade connectors and a new relay. I will just add in a second one with a toggle somewhere hidden. This will keep the original wiring in tact, and if im cruising down the road and it shits out I can just hit the switch and keep rolling.

 

This little relay cost me over a 100 bucks today that I really didn't have to spend. I don't have money to throw at this, nor the time to investigate it at this time. Its working as it should right now, but I'd rather have a backup switch instead of being stranded in 30 degree weather on the side of the road. Waited over an hour for a ride, then had to go tow it home today. That sucked.

 

I do plan on replacing the oil sensor unit this coming weekend weather and $ permitting. If it proves itself after a few months or so of not crapping out, I can just remove the spare relay or leave it there forever. Won't matter. I will hide it and do it right and it will just be a backup.

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This is what I did.

 

 

I used the accessories as the battery, the alternator as the trigger. This is just a temp solution... Till i can throw in a new oil pressure switch. I also now know how to bypass it altogether if i get stuck on the side of the road... So, this is my temp fix.

 

2011-12-12_11-19-18_262.jpg

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Good doin'. I don't know what the accessory connection does. It would only be on when the engine is off, so maybe it shuts the timer off so the pump doesn't run when you turn off and switch to the accessory .

 

Did anyone notice that the 720 room lamp timer is basically the same relay? Keeps the interior lamp on for about 3 min after you close the rood when you get out. Naturally if you were getting in and starting up to drive you wouldn't want the interior lamp on so there must be some input that shuts it off.

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with key on

 

the accessory wire is hot, along with the fuse five iirc, and alt. i forgot to check the oil pressure switch wire. Learn something new every day. Like i said this is just a temp fix though.

 

It sounds like fuse 5 is the supply power to the FP. Is it on in the accessory spot? I wouldnt want it to be because then you are running the FP if you ever just turn on accessory power and not running the car.

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