a couple questions - rewiring fuel pump
03-23-11, 09:58 PM
#1
a couple questions - rewiring fuel pump
ive got a couple (probably simple) questions while rewiring my fuel pump. i just want to be triple sure i am doing this correctly. i have a haltech and am only using the stock wiring for the fuel level gauge. i am using the stock sending unit in the stock tank. 87 turbo 2. i have looked at the FSM and could not find the answer to question 1.
1. there are 4 wires coming off the body harness that connect to the fuel pump sending unit:
white/green
white/red
blue
black
what are each of these wires for?
2. is this correct?
85 - switched 12v
86 - from haltech
87 - to battery (fused)
30 - to fuel pump power wire
87a - not connected
thanks
1. there are 4 wires coming off the body harness that connect to the fuel pump sending unit:
white/green
white/red
blue
black
what are each of these wires for?
2. is this correct?
85 - switched 12v
86 - from haltech
87 - to battery (fused)
30 - to fuel pump power wire
87a - not connected
thanks
03-24-11, 12:33 AM
#2
1. Pgs. 50-34 & 50-40
white/green - Fuel level sender to gauge
white/red - low fuel warning light
blue - +12v to fuel pump
black - fuel pump ground
2. I'm not sure it matters in your case, but pin 30 is typically the fused +12V source, and 87 is connected to whatever you want to power. So I'd have it like this:
85 - switched 12v
86 - from haltech
30 - from battery (fused)
87 - to fuel pump power wire
87a - not connected
white/green - Fuel level sender to gauge
white/red - low fuel warning light
blue - +12v to fuel pump
black - fuel pump ground
2. I'm not sure it matters in your case, but pin 30 is typically the fused +12V source, and 87 is connected to whatever you want to power. So I'd have it like this:
85 - switched 12v
86 - from haltech
30 - from battery (fused)
87 - to fuel pump power wire
87a - not connected
03-24-11, 07:19 AM
#3
thanks a lot. one other question... do i have to ground the body harness side and the fuel pump side ground wires? or can i leave the body harness side disconnected and only ground the fuel pump side?
Last edited by 87 t-66; 03-24-11 at 07:36 AM.
03-24-11, 02:05 PM
#4
So you're talking about cutting the black wire off above the fuel pump assembly, grounding the pump side somewhere (new wire from the battery or engine block?), then leaving the other half of the black wire alone? That should work. If you're worried about it, you can solder the 3 ends together.
03-24-11, 02:07 PM
#5
So you're talking about cutting the black wire off above the fuel pump assembly, grounding the pump side somewhere (new wire from the battery or engine block?), then leaving the other half of the black wire alone? That should work. If you're worried about it, you can solder the 3 ends together.
03-24-11, 02:18 PM
#7
those color wires don't jive with what i experience with just about all series RX7 from the top of the pump housing to the 4 pin connector, unless you are referring to inside the pump housing.
the blue and red wires are for the sender unit and low level sensor, the black wire is for ground and the black/white wire is for the fuel pump power source.
been there and done that, the blue wire won't give you power to the fuel pump so avoid chasing your tail if you are just looking for the blue wire without assessing the color of the rest of the wires in the circuit where you are patching it in.
every model year from 87-95 i have run into, off the top of the tank the back/white wire is the one you need. once inside the tank, if i recall, the power wire is then blue to the fuel pump on some models. i wanted to punch a baby after dealing with that one for a while because the manuals don't specify that last junction before the pump and the varying color wires in the circuit. to be sure, simply take out the pump and verify the + symbol off the pump itself and trace the wire back which can save you alot of confusion and headaches.
i just checked 2 FCs, S4 and S5 non turbo and turbo and they both had the black/white pump power wire, blue + red sending unit wires and solid back ground wiring.
if by those color wiring you are referring the the body connector side of the harness, well, i honestly never patch in the feed on the connector side. it defeats the purpose of bypassing as much of the stock wiring and connectors as possible. i always cut the black/white wire as close to the top of the fuel tank sump assembly as possible to decrease the amount of resistance and failure points in the system as possible. yes this creates an issue with removing the pump completely from the car but i usually work on it in the hatch area anyways, connected to the vehicle still with a catch pan under it. it's simply a pain to get to the connector under the strut tower carpet cover that i never disassemble any cars to get to it anyways for a full removal.
also be sure to solder connections and use high grade connectors for the relay, preferably gold plated with thicker gauge wiring like 10 gauge. there is no problem with adding another ground to the top of the tank sender/pump housing either, since the fuel pump is grounded off the chassis of the housing anyways. s5 passes through the connector for an isolated ground, which i am not a fan of the S5 style pump housing at all anyways.
the blue and red wires are for the sender unit and low level sensor, the black wire is for ground and the black/white wire is for the fuel pump power source.
been there and done that, the blue wire won't give you power to the fuel pump so avoid chasing your tail if you are just looking for the blue wire without assessing the color of the rest of the wires in the circuit where you are patching it in.
every model year from 87-95 i have run into, off the top of the tank the back/white wire is the one you need. once inside the tank, if i recall, the power wire is then blue to the fuel pump on some models. i wanted to punch a baby after dealing with that one for a while because the manuals don't specify that last junction before the pump and the varying color wires in the circuit. to be sure, simply take out the pump and verify the + symbol off the pump itself and trace the wire back which can save you alot of confusion and headaches.
i just checked 2 FCs, S4 and S5 non turbo and turbo and they both had the black/white pump power wire, blue + red sending unit wires and solid back ground wiring.
if by those color wiring you are referring the the body connector side of the harness, well, i honestly never patch in the feed on the connector side. it defeats the purpose of bypassing as much of the stock wiring and connectors as possible. i always cut the black/white wire as close to the top of the fuel tank sump assembly as possible to decrease the amount of resistance and failure points in the system as possible. yes this creates an issue with removing the pump completely from the car but i usually work on it in the hatch area anyways, connected to the vehicle still with a catch pan under it. it's simply a pain to get to the connector under the strut tower carpet cover that i never disassemble any cars to get to it anyways for a full removal.
also be sure to solder connections and use high grade connectors for the relay, preferably gold plated with thicker gauge wiring like 10 gauge. there is no problem with adding another ground to the top of the tank sender/pump housing either, since the fuel pump is grounded off the chassis of the housing anyways. s5 passes through the connector for an isolated ground, which i am not a fan of the S5 style pump housing at all anyways.
Last edited by RotaryEvolution; 03-24-11 at 02:34 PM.
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03-24-11, 02:52 PM
#8
those color wires don't jive with what i experience with just about all series RX7 from the top of the pump housing to the 4 pin connector, unless you are referring to inside the pump housing.
the blue and red wires are for the sender unit and low level sensor, the black wire is for ground and the black/white wire is for the fuel pump power source.
been there and done that, the blue wire won't give you power to the fuel pump so avoid chasing your tail if you are just looking for the blue wire without assessing the color of the rest of the wires in the circuit where you are patching it in.
every model year from 87-95 i have run into, off the top of the tank the back/white wire is the one you need. once inside the tank, if i recall, the power wire is then blue to the fuel pump on some models. i wanted to punch a baby after dealing with that one for a while because the manuals don't specify that last junction before the pump and the varying color wires in the circuit. to be sure, simply take out the pump and verify the + symbol off the pump itself and trace the wire back which can save you alot of confusion and headaches.
i just checked 2 FCs, S4 and S5 non turbo and turbo and they both had the black/white pump power wire, blue + red sending unit wires and solid back ground wiring.
if by those color wiring you are referring the the body connector side of the harness, well, i honestly never patch in the feed on the connector side. it defeats the purpose of bypassing as much of the stock wiring and connectors as possible. i always cut the black/white wire as close to the top of the fuel tank sump assembly as possible to decrease the amount of resistance and failure points in the system as possible. yes this creates an issue with removing the pump completely from the car but i usually work on it in the hatch area anyways, connected to the vehicle still with a catch pan under it. it's simply a pain to get to the connector under the strut tower carpet cover that i never disassemble any cars to get to it anyways for a full removal.
also be sure to solder connections and use high grade connectors for the relay, preferably gold plated with thicker gauge wiring like 10 gauge. there is no problem with adding another ground to the top of the tank sender/pump housing either, since the fuel pump is grounded off the chassis of the housing anyways. s5 passes through the connector for an isolated ground, which i am not a fan of the S5 style pump housing at all anyways.
the blue and red wires are for the sender unit and low level sensor, the black wire is for ground and the black/white wire is for the fuel pump power source.
been there and done that, the blue wire won't give you power to the fuel pump so avoid chasing your tail if you are just looking for the blue wire without assessing the color of the rest of the wires in the circuit where you are patching it in.
every model year from 87-95 i have run into, off the top of the tank the back/white wire is the one you need. once inside the tank, if i recall, the power wire is then blue to the fuel pump on some models. i wanted to punch a baby after dealing with that one for a while because the manuals don't specify that last junction before the pump and the varying color wires in the circuit. to be sure, simply take out the pump and verify the + symbol off the pump itself and trace the wire back which can save you alot of confusion and headaches.
i just checked 2 FCs, S4 and S5 non turbo and turbo and they both had the black/white pump power wire, blue + red sending unit wires and solid back ground wiring.
if by those color wiring you are referring the the body connector side of the harness, well, i honestly never patch in the feed on the connector side. it defeats the purpose of bypassing as much of the stock wiring and connectors as possible. i always cut the black/white wire as close to the top of the fuel tank sump assembly as possible to decrease the amount of resistance and failure points in the system as possible. yes this creates an issue with removing the pump completely from the car but i usually work on it in the hatch area anyways, connected to the vehicle still with a catch pan under it. it's simply a pain to get to the connector under the strut tower carpet cover that i never disassemble any cars to get to it anyways for a full removal.
also be sure to solder connections and use high grade connectors for the relay, preferably gold plated with thicker gauge wiring like 10 gauge. there is no problem with adding another ground to the top of the tank sender/pump housing either, since the fuel pump is grounded off the chassis of the housing anyways. s5 passes through the connector for an isolated ground, which i am not a fan of the S5 style pump housing at all anyways.
Last edited by 87 t-66; 03-24-11 at 02:59 PM.
05-02-11, 09:41 PM
#10
1. Pgs. 50-34 & 50-40
white/green - Fuel level sender to gauge
white/red - low fuel warning light
blue - +12v to fuel pump
black - fuel pump ground
2. I'm not sure it matters in your case, but pin 30 is typically the fused +12V source, and 87 is connected to whatever you want to power. So I'd have it like this:
85 - switched 12v
86 - from haltech
30 - from battery (fused)
87 - to fuel pump power wire
87a - not connected
white/green - Fuel level sender to gauge
white/red - low fuel warning light
blue - +12v to fuel pump
black - fuel pump ground
2. I'm not sure it matters in your case, but pin 30 is typically the fused +12V source, and 87 is connected to whatever you want to power. So I'd have it like this:
85 - switched 12v
86 - from haltech
30 - from battery (fused)
87 - to fuel pump power wire
87a - not connected
http://www.docstoc.com/docs/26736448...ing-Diagramcdr
Last edited by 87 t-66; 05-02-11 at 09:51 PM.
05-02-11, 11:37 PM
#11
Rotary Freak
The Black wire in the Rear harness plug is for the pumps ground.
Soooo? That black wire mates with a wire on the pumps pigtail harness. Is the wire the black mates with, being grounded right now? In other words the black wire in the Rear harness side of the plug does not need to be grounded but the wire it mates with sure does.
What's this hattech ECU do? Does it put a ground on the relays coil???? at 86? That's the only way that relay will ever pull in. So that must be the case.
Soooo? That black wire mates with a wire on the pumps pigtail harness. Is the wire the black mates with, being grounded right now? In other words the black wire in the Rear harness side of the plug does not need to be grounded but the wire it mates with sure does.
What's this hattech ECU do? Does it put a ground on the relays coil???? at 86? That's the only way that relay will ever pull in. So that must be the case.
05-02-11, 11:43 PM
#12
Rotary Freak
The large Blue wire in the plug is power to the fuel pump on stk car.
The Black wire is the ground for the pump.
The White/Green is for the fuel gauge.
The White/Red is for fuel low warning light.
Is the Blue wire getting power when the key is turned to START? Is the Blue wire getting power if the fuel pump check connecter is jumpered?
Is the fuel pumps ground wire grounded?
The Black wire is the ground for the pump.
The White/Green is for the fuel gauge.
The White/Red is for fuel low warning light.
Is the Blue wire getting power when the key is turned to START? Is the Blue wire getting power if the fuel pump check connecter is jumpered?
Is the fuel pumps ground wire grounded?
thanks for the help
05-03-11, 07:34 PM
#14
here's where i am at...
the fuel pump will not prime when i turn the key on. the haltech has a single O/GY wire that should ground and activate the relay i installed by the fuel pump. when i ground the wire on pin 86, the relay clicks and the pump turns on. i am hearing the fuel pump relay on the haltech click when i turn the key on, but that damn wire doesn't ground. i just re-ran that wire to the relay so i know it is not messed up.
the fuel pump will not prime when i turn the key on. the haltech has a single O/GY wire that should ground and activate the relay i installed by the fuel pump. when i ground the wire on pin 86, the relay clicks and the pump turns on. i am hearing the fuel pump relay on the haltech click when i turn the key on, but that damn wire doesn't ground. i just re-ran that wire to the relay so i know it is not messed up.
08-17-11, 09:10 PM
#16
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I just did this wiring.
If you use the pump side wiring Before the Car connector,then you splice the Black/White for Positive,and the Black for Neg/GR. the pump will run without any extra ground being added to the harness,as it is already grounded.(providing car and pump connector is hooked together).
Adam: I see where you went wrong with the Diagram posted..and 85 is negative.(the old way had your coil side to 2 positives).
If you use the pump side wiring Before the Car connector,then you splice the Black/White for Positive,and the Black for Neg/GR. the pump will run without any extra ground being added to the harness,as it is already grounded.(providing car and pump connector is hooked together).
Adam: I see where you went wrong with the Diagram posted..and 85 is negative.(the old way had your coil side to 2 positives).
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