Who wants to help me with fuel pump relay wiring?
01-11-2010, 06:26 PM
#1
Who wants to help me with fuel pump relay wiring? Ok, I'm wiring up my new fuel pump in my 86'. I'm running new power/ground wires to the pump and running the relay supplied with the kit. Now, this setup calls for an on/off switch or ignition power so the pump runs with the ignition on, but I think I can use the stock ECM setup to cycle the pump. Here's a bad drawing of the stock relay (large drawing) and new aftermarket (small drawing)
K, the stock wiring goes like this:
Red=Fuel Pump Prime Connector
Orange= Hot at all times with inline fuse
Blk/White= Ground
Tan/Wht=Powers Pump (according to austin thirdgen, my diagram shows it going to the ecm but doesn't say what for)
Dk/Grn wht= Fuel pump prime, this wire becomes "hot" for a few seconds when I turn the key
My new relay says to do this (has new wiring harness with it):
red=not used
yellow= to fuelpump +
black= ground
blue=to battery + with inline fuse
wht= to on/off switch or ignition power
I'm thinking I can use this relay to serve the same purpose as the stock one based on the diagram, they look to work the same way. I'm thinking I should wire it this way
Stock Red=Red
Stock Orange= Yellow
Stock Black/wht=Black
Stock Tan/Wht=Blue
Stock DK GRN/WHT=White
What do you guys think? That basically goes against what the directions say to do with the new relay but it looks to work the same as the stock setup in design. What do you guys think? I'd like to get this wired up tonight. The stock style setup uses the relay for just priming of the pump, there is an oil pressure switch inline on the main power that activates the fuel pump once oil pressure is built. I'd like to keep this feature. You can pull the relay off while it's running and it will continue to run without it, also if I ever lose oil pressure it'll shut the engine off. Always a nice feature
K, the stock wiring goes like this:
Red=Fuel Pump Prime Connector
Orange= Hot at all times with inline fuse
Blk/White= Ground
Tan/Wht=Powers Pump (according to austin thirdgen, my diagram shows it going to the ecm but doesn't say what for)
Dk/Grn wht= Fuel pump prime, this wire becomes "hot" for a few seconds when I turn the key
My new relay says to do this (has new wiring harness with it):
red=not used
yellow= to fuelpump +
black= ground
blue=to battery + with inline fuse
wht= to on/off switch or ignition power
I'm thinking I can use this relay to serve the same purpose as the stock one based on the diagram, they look to work the same way. I'm thinking I should wire it this way
Stock Red=Red
Stock Orange= Yellow
Stock Black/wht=Black
Stock Tan/Wht=Blue
Stock DK GRN/WHT=White
What do you guys think? That basically goes against what the directions say to do with the new relay but it looks to work the same as the stock setup in design. What do you guys think? I'd like to get this wired up tonight. The stock style setup uses the relay for just priming of the pump, there is an oil pressure switch inline on the main power that activates the fuel pump once oil pressure is built. I'd like to keep this feature. You can pull the relay off while it's running and it will continue to run without it, also if I ever lose oil pressure it'll shut the engine off. Always a nice feature
Last edited by 1FSTZ71; 01-12-2010 at 12:47 AM.
01-12-2010, 03:16 AM
#2
First, your stock relay is merely a Bosch-style relay. It has 5 terminals, normally referred to with numbers, rather than wire colors. I will put both, so they translate directly over.
30 – Fused 12 Volt source (generally battery or alternator)
85 – Ground
86 – Triggering switch (generally key-on or Hobbs switch for F/I)
87 – On when relay powered (receives power from 30)
87a - On when relay not powered (seldom used, but available)
Translating to the original relay wiring
30 - Tan/white (this is reversed from the standard, but electrically acceptable)
85 - Blk/White
86 - Dk/Grn wht
87 - Orange
87a - Red
Translating to new relay
30 - blue (this is the standard configuration)
85 - black
86 - wht
87 - yellow
87a - red
Note, you can interchange 30 & 87, so that 30 can be yellow, and 87 can be blue
Using your notes:
Stock Red=Red (Yes)
Stock Orange= Yellow (Yes)
Stock Black/wht=Black (Yes)
Stock Tan/Wht=Blue (Yes)
Stock DK GRN/WHT=White (Yes)
Short answer, yes, you are correct, it should work just as the original relay worked.
30 – Fused 12 Volt source (generally battery or alternator)
85 – Ground
86 – Triggering switch (generally key-on or Hobbs switch for F/I)
87 – On when relay powered (receives power from 30)
87a - On when relay not powered (seldom used, but available)
Translating to the original relay wiring
30 - Tan/white (this is reversed from the standard, but electrically acceptable)
85 - Blk/White
86 - Dk/Grn wht
87 - Orange
87a - Red
Translating to new relay
30 - blue (this is the standard configuration)
85 - black
86 - wht
87 - yellow
87a - red
Note, you can interchange 30 & 87, so that 30 can be yellow, and 87 can be blue
Using your notes:
Stock Red=Red (Yes)
Stock Orange= Yellow (Yes)
Stock Black/wht=Black (Yes)
Stock Tan/Wht=Blue (Yes)
Stock DK GRN/WHT=White (Yes)
Short answer, yes, you are correct, it should work just as the original relay worked.
01-12-2010, 05:08 AM
#3
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First, your stock relay is merely a Bosch-style relay. It has 5 terminals, normally referred to with numbers, rather than wire colors. I will put both, so they translate directly over.
30 – Fused 12 Volt source (generally battery or alternator)
85 – Ground
86 – Triggering switch (generally key-on or Hobbs switch for F/I)
87 – On when relay powered (receives power from 30)
87a - On when relay not powered (seldom used, but available).
30 – Fused 12 Volt source (generally battery or alternator)
85 – Ground
86 – Triggering switch (generally key-on or Hobbs switch for F/I)
87 – On when relay powered (receives power from 30)
87a - On when relay not powered (seldom used, but available).
01-12-2010, 08:07 AM
#4
Im running dual walbros and 1 is using a Hobbs for trigger. based on this I can use 1 relay for both pumps. Setup the pump i want to run all the time to 87a since its always on even when relay isnt triggered, and setup the second pump to 87 while hooking up the hobbs switch to 86. is that right?
If you look at the pivot point (Tan/wht or blue) the top point pivots between 87a & 87. The coil, activated by (dk grn/wht & bkk/wht) or (wht & black) pulls the lever to the 87 terminal when the relay is powered. When the relay is unpowered again, it switches back to 87a.
01-12-2010, 03:38 PM
#5
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Ahhh so 87a is powered until the relay is powered then it switches from 87a to 87. Gotcha.
Where would you recommend getting a relay kit(mainly concerned with the gauge of wire w/socket)
Where would you recommend getting a relay kit(mainly concerned with the gauge of wire w/socket)
01-12-2010, 04:18 PM
#6
Sources are limitless. You can go down to the local autoparts and purchase an inexpensive one, or you can go to a sponsor such as lsxtune and purchase a weatherproof one. I purchased a 5 pack of relays and sockets on fleabay, then weatherproofed them with judicious use of silicone sealant and dlelectric grease.
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05-24-2010, 05:52 PM
#13
Back from the dead....okay so I am starting my 2nd pump install and I was wondering if I want mine to run all the time (I don't mind changing pumps it's easy) would how in the heck could I wire this up.
I would use a fused wire to the battery and use the trigger from the PCM?
I would run the wire on the passenger side of the car so what can i use for the key one wire?
And do I need 2 grounds: 1)relay, 2)fuel pump?
I would use a fused wire to the battery and use the trigger from the PCM?
I would run the wire on the passenger side of the car so what can i use for the key one wire?
And do I need 2 grounds: 1)relay, 2)fuel pump?
05-24-2010, 09:14 PM
#14
May I ask why you feel the need to run both pumps all the time? You really only need the second pump during times of high demand.
Many claim issues will arise if you try this, although I have no personal experience trying this.
The relay should have a fused wire to the battery or alternator. I personally prefer the alternator, since it is the source of electrical power when the engine is running.
The switch (to activate the relay, and thus the pump) is whatever you decide. Most use something that coincides with high demand situations.
You must ground both the fuel pump and the relay. I prefer to ground my devices as close to the device as possible (shorter wires, easier to debug), so I would use two grounds.
Many claim issues will arise if you try this, although I have no personal experience trying this.
The relay should have a fused wire to the battery or alternator. I personally prefer the alternator, since it is the source of electrical power when the engine is running.
The switch (to activate the relay, and thus the pump) is whatever you decide. Most use something that coincides with high demand situations.
You must ground both the fuel pump and the relay. I prefer to ground my devices as close to the device as possible (shorter wires, easier to debug), so I would use two grounds.
05-25-2010, 01:29 AM
#15
May I ask why you feel the need to run both pumps all the time? You really only need the second pump during times of high demand.
Many claim issues will arise if you try this, although I have no personal experience trying this.
The relay should have a fused wire to the battery or alternator. I personally prefer the alternator, since it is the source of electrical power when the engine is running.
The switch (to activate the relay, and thus the pump) is whatever you decide. Most use something that coincides with high demand situations.
You must ground both the fuel pump and the relay. I prefer to ground my devices as close to the device as possible (shorter wires, easier to debug), so I would use two grounds.
Many claim issues will arise if you try this, although I have no personal experience trying this.
The relay should have a fused wire to the battery or alternator. I personally prefer the alternator, since it is the source of electrical power when the engine is running.
The switch (to activate the relay, and thus the pump) is whatever you decide. Most use something that coincides with high demand situations.
You must ground both the fuel pump and the relay. I prefer to ground my devices as close to the device as possible (shorter wires, easier to debug), so I would use two grounds.
