Swapping to 1500, building a harness
01-21-23, 04:59 PM
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Swapping to 1500, building a harness
I'm swapping to a 1500 and doing research on building the harness (which I've never done), so I have a few questions and will probably have more, if anyone can answer. This is on an FD btw.
I have a bit of a head start because I have a harness that Chris Ludwig built for my previous setup and I've been reverse engineering it to a degree, and I plan on using some of the parts that he made (sub-harnesses for the relay box, battery cables, possibly water injection pump relay, etc). I bought the flying lead harness for the ECU. I wish the wire quality was better, but I'm trying to save money a bit and it should serve it's purpose for now. Maybe later I'll make another harness with better wiring and I'll use this one as a template. One reason I got the flying lead was because I don't have any experience building one and I figured it would help at least having the wiring correct for the ECU side. I've planned out for the most part which wires I need to add, which wires go to which connectors and which terminal in the connector they need to go to, etc.
1. In the harness Chris built, the crank angle sensor gets power from the EGI relay through X-05. Would it be OK if I tapped into that same power for the purge solenoid valve (for the EVAP system) and the IAC since that's where they get power in the stock harness, or should I just leave those for CAS? Or is the CAS wiring in the Haltech harness getting it's power from somewhere else already? Also, does anyone know if it matters which wire goes where in the EVAP solenoid connector? In the wiring diagram, G/Y goes to 3H in the ECU connector and B/W comes from the EGI relay, but I'm not sure which wires goes to which side of the connector or if it matters. I'm adding this back in right now so I have nothing from before to reference.
2. Do I need to branch off the speed sensor wiring from the transmission to go to the ECU and also the stock connector? Or just to the ECU? I'm using a Speedhut GPS speedo so I wouldn't need a speed reference for the gauge.
3. I was told I need to run a wire to the power steering switch but I don't have a wire for that in the harness Chris built, and all that wiring goes through the other engine harness anyway (the battery/starter harness). Do I need to tap into the stock connector for that too? Is this a Haltech thing?
4. For the check engine light wire, I see it goes through connector B1-20 terminal K for the electrical load control unit. Would I just run the wire from the ECU into that terminal on the connector, or is there somewhere else I need to tap into?
5. Chris tapped into the SPA Techniques sensor wiring for the oil pressure sensor, but used only one of the three wires. I'm assuming it already gets power and ground through the gauge wiring and doesn't need power and ground through the ECU wiring. I'm going to need to tap into my fuel pressure sensor wiring the same way, although I've been thinking about replacing both sensors and building the harness for it with two outputs for each, one for the gauge and one for the ECU. Should I wire it the same way, with only one of them getting power and ground?
6. Chris built a separate harness for the water injection pump which contains a relay. I'm thinking about adding this to the relay box he installed instead of having it separate. I guess this isn't so much of a question other than asking for advice. I don't see why it wouldn't work. I was planning on just putting the sub-harness back in but if I can clean up the wiring a little more, I'd like to. I have a solenoid from Holley (just like the one I had with the FJO kit), I assume that doesn't need a relay since we didn't use one this last time. Then again, my water injection system only worked for about half an hour one day lol. We just couldn't figure out the issue.
7. I wasn't planning on using a wire to the clutch switch but Chris' harness has one. I don't see a need for it though, but there's a lot I don't know about this subject lol.
I have a bit of a head start because I have a harness that Chris Ludwig built for my previous setup and I've been reverse engineering it to a degree, and I plan on using some of the parts that he made (sub-harnesses for the relay box, battery cables, possibly water injection pump relay, etc). I bought the flying lead harness for the ECU. I wish the wire quality was better, but I'm trying to save money a bit and it should serve it's purpose for now. Maybe later I'll make another harness with better wiring and I'll use this one as a template. One reason I got the flying lead was because I don't have any experience building one and I figured it would help at least having the wiring correct for the ECU side. I've planned out for the most part which wires I need to add, which wires go to which connectors and which terminal in the connector they need to go to, etc.
1. In the harness Chris built, the crank angle sensor gets power from the EGI relay through X-05. Would it be OK if I tapped into that same power for the purge solenoid valve (for the EVAP system) and the IAC since that's where they get power in the stock harness, or should I just leave those for CAS? Or is the CAS wiring in the Haltech harness getting it's power from somewhere else already? Also, does anyone know if it matters which wire goes where in the EVAP solenoid connector? In the wiring diagram, G/Y goes to 3H in the ECU connector and B/W comes from the EGI relay, but I'm not sure which wires goes to which side of the connector or if it matters. I'm adding this back in right now so I have nothing from before to reference.
2. Do I need to branch off the speed sensor wiring from the transmission to go to the ECU and also the stock connector? Or just to the ECU? I'm using a Speedhut GPS speedo so I wouldn't need a speed reference for the gauge.
3. I was told I need to run a wire to the power steering switch but I don't have a wire for that in the harness Chris built, and all that wiring goes through the other engine harness anyway (the battery/starter harness). Do I need to tap into the stock connector for that too? Is this a Haltech thing?
4. For the check engine light wire, I see it goes through connector B1-20 terminal K for the electrical load control unit. Would I just run the wire from the ECU into that terminal on the connector, or is there somewhere else I need to tap into?
5. Chris tapped into the SPA Techniques sensor wiring for the oil pressure sensor, but used only one of the three wires. I'm assuming it already gets power and ground through the gauge wiring and doesn't need power and ground through the ECU wiring. I'm going to need to tap into my fuel pressure sensor wiring the same way, although I've been thinking about replacing both sensors and building the harness for it with two outputs for each, one for the gauge and one for the ECU. Should I wire it the same way, with only one of them getting power and ground?
6. Chris built a separate harness for the water injection pump which contains a relay. I'm thinking about adding this to the relay box he installed instead of having it separate. I guess this isn't so much of a question other than asking for advice. I don't see why it wouldn't work. I was planning on just putting the sub-harness back in but if I can clean up the wiring a little more, I'd like to. I have a solenoid from Holley (just like the one I had with the FJO kit), I assume that doesn't need a relay since we didn't use one this last time. Then again, my water injection system only worked for about half an hour one day lol. We just couldn't figure out the issue.
7. I wasn't planning on using a wire to the clutch switch but Chris' harness has one. I don't see a need for it though, but there's a lot I don't know about this subject lol.
Last edited by speedjunkie; 01-21-23 at 07:47 PM.
01-29-23, 06:52 PM
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I've since been told it doesn't matter which wire goes to which side of the purge solenoid connector.
There have been some new developments regarding WI since I typed up this post. I've been discussing with a friend that is also researching the topic and I'm now looking into getting a solenoid driver to pulse the solenoid (Low Amp Solenoid Driver : USRT, Usually Sideways Rally Team (usrallyteam.com), and running the pump off a relay, but I'm still not 100% this is correct. It kinda makes sense though, considering I'm somewhat mimicking my old FJO kit and it had a controller that pulsed the solenoid, and the WI solenoid circuit is what burned inside the Syvecs.
There have been some new developments regarding WI since I typed up this post. I've been discussing with a friend that is also researching the topic and I'm now looking into getting a solenoid driver to pulse the solenoid (Low Amp Solenoid Driver : USRT, Usually Sideways Rally Team (usrallyteam.com), and running the pump off a relay, but I'm still not 100% this is correct. It kinda makes sense though, considering I'm somewhat mimicking my old FJO kit and it had a controller that pulsed the solenoid, and the WI solenoid circuit is what burned inside the Syvecs.
02-01-23, 07:22 PM
#4
Regarding the water injection. I used to have a variable controller for the pump. Will be going the solenoid route as I redo it though.
Regular 12V relay to turn on the pump (can set at a psi or rpm or combo). Simple on / off.
Then PWM for solenoid. I think you already found it, but need to make sure the solenoid doesn't take too many amps if controlling directly from the ECU. Otherwise, use a solid state relay driven by the ECU.
Regular 12V relay to turn on the pump (can set at a psi or rpm or combo). Simple on / off.
Then PWM for solenoid. I think you already found it, but need to make sure the solenoid doesn't take too many amps if controlling directly from the ECU. Otherwise, use a solid state relay driven by the ECU.
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speedjunkie (02-02-23)
02-02-23, 11:19 PM
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Thanks for your input!
So you used to use your pump to vary the amount of fluid being injected?
I had a relay on the pump with the Syvecs, but it would chatter and not actually power the pump, IIRC. We tried changing outputs in the ECU, but nothing worked. I was wondering if I maybe needed to run a driver on the pump as well, or a solid state relay or diode relay. We never did figure out why it wouldn't work.
When you say PWM, would that driver that I liked work for this? I don't know much about all this. So basically a solid state relay from the ECU, then to a PWM/solenoid driver, then to the solenoid?
I also reached out to Haltech and they told me to just use a relay, but that doesn't address the ECU taking too many amps. I'm really not trying to fry this ECU as well. This was their response.
"Thanks for reaching out to Haltech support. We do have a water injection function and a water injection advanced function in the NSP software. (this function will take up 2 of your DPOs if you want the ecu to control the solenoid and the pump.) *this is also an advanced option, use with caution & consult your tuner as well
This function would control the solenoid portion of the system and needs wired to a DPO output on elite ECU.
You would want to set the pump up as a generic and have it come on and prime the system when you want it. This can be set up based on many conditions in the system. This pump will need a relay to activate it. You will use a DPO to control the ground side / trigger of the relay to send power to the pump."
So you used to use your pump to vary the amount of fluid being injected?
I had a relay on the pump with the Syvecs, but it would chatter and not actually power the pump, IIRC. We tried changing outputs in the ECU, but nothing worked. I was wondering if I maybe needed to run a driver on the pump as well, or a solid state relay or diode relay. We never did figure out why it wouldn't work.
When you say PWM, would that driver that I liked work for this? I don't know much about all this. So basically a solid state relay from the ECU, then to a PWM/solenoid driver, then to the solenoid?
I also reached out to Haltech and they told me to just use a relay, but that doesn't address the ECU taking too many amps. I'm really not trying to fry this ECU as well. This was their response.
"Thanks for reaching out to Haltech support. We do have a water injection function and a water injection advanced function in the NSP software. (this function will take up 2 of your DPOs if you want the ecu to control the solenoid and the pump.) *this is also an advanced option, use with caution & consult your tuner as well
This function would control the solenoid portion of the system and needs wired to a DPO output on elite ECU.
You would want to set the pump up as a generic and have it come on and prime the system when you want it. This can be set up based on many conditions in the system. This pump will need a relay to activate it. You will use a DPO to control the ground side / trigger of the relay to send power to the pump."
Last edited by speedjunkie; 02-02-23 at 11:26 PM.
02-03-23, 12:05 AM
#6
It depends how you had your syvecs wired to the pump. If you were trying to make it variable, had a regular relay switching on and off, it can react quick enough to vary the voltage to the pump to speed it up or down, you are just giving it a spotty 12 volts.
Most kits with a stand alone controller that you buy are are essentially varying the voltage supplied to the pump and making it flow more or less based on the settings.
The way to do this with an ECU is to use a DPO, set to PWM function (changes voltage by received by electric pump motor by pulsing 12v to it rapidly. You need a solid state relay in order for this to work. This is assuming you are supplying power to the pump via relay connected to the battery and not trying to supply directly from the ECU (which could be bad if not rated for the amperage).
The nice thing about the solenoid setup is that you just do a simple regular relay to supply constant 12v to the pump from the battery (you can use the DPO from the ECU to ground/trigger the relay when appropriate as you don't need the pump running all the time. Then you can use another DPO to the solenoid, which likely doesn't draw enough amps to require you to need a solid state relay pulling power directly from the battery.
Most kits with a stand alone controller that you buy are are essentially varying the voltage supplied to the pump and making it flow more or less based on the settings.
The way to do this with an ECU is to use a DPO, set to PWM function (changes voltage by received by electric pump motor by pulsing 12v to it rapidly. You need a solid state relay in order for this to work. This is assuming you are supplying power to the pump via relay connected to the battery and not trying to supply directly from the ECU (which could be bad if not rated for the amperage).
The nice thing about the solenoid setup is that you just do a simple regular relay to supply constant 12v to the pump from the battery (you can use the DPO from the ECU to ground/trigger the relay when appropriate as you don't need the pump running all the time. Then you can use another DPO to the solenoid, which likely doesn't draw enough amps to require you to need a solid state relay pulling power directly from the battery.
02-04-23, 10:35 PM
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The nice thing about the solenoid setup is that you just do a simple regular relay to supply constant 12v to the pump from the battery (you can use the DPO from the ECU to ground/trigger the relay when appropriate as you don't need the pump running all the time. Then you can use another DPO to the solenoid, which likely doesn't draw enough amps to require you to need a solid state relay pulling power directly from the battery.
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