Help with S14 A/C lines - What am I missing - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

lagvoid21 · 01-20-2017, 08:13 PM

A/C was removed a long time ago and I'd love to get it back up in my S14 with S13 redtop SR20DET. I plan to get Codyace's bracket, but I know I'm missing lines and connections as well.

I have some questions weaved into what I think I know, but please correct me if I'm mistaken. I've searched through every A/C related page I could find.

1 - What does the circled plug coming from the receiver drier connect to? Was this a connection to the stock radiator fan or an A/C component?

01.jpg

2 - The circled A/C line runs from the receiver drier towards the passenger firewall. What I circled ends there with no connection to the firewall.

02.jpg

Referencing this parts diagram, it looks like line 14, but the connection at the firewall side doesn't look the same.
3795120.png

3 - The connection circled here is at the passenger firewall. This looks like what part 17 from the parts diagram would connect to. I've searched, but can't seem to find this part at all or it's name. I'm also missing part 18, the line that runs over/behind the engine. I believe part 18 is the A/C low pressure suction line.

03.jpg

4 - This is the original low pressure line for this car. I believe this connects to the missing part 17 & 18 mentioned above. It seems I need to get lines from a 1995 as well to ensure it matches up.

04.jpg

5 - The high pressure line connecting to the condenser is still in place

05.jpg

Am I missing anything else besides the A/C compressor and Codyace bracket itself to complete the hardware connections?

Thanks for your time!

dbeiler · 01-21-2017, 04:21 PM

Quote:

Originally Posted by lagvoid21

1 - What does the circled plug coming from the receiver drier connect to? Was this a connection to the stock radiator fan or an A/C component?

Attachment 97709

That connector is for the factory radiator fans, yes.

This is the S14 AC system layout (minus condenser and evaporator)

These are the firewall connections

lagvoid21 · 01-21-2017, 06:40 PM

WOW, thank you so much for such helpful pictures and information! I've read that the A/C lines vary between 95 and later models of the s14. The connection points are supposedly sized differently. Would you happen to know if this is true for the firewall connection point as well? Would I be able to use all the A/C lines (from a 97 240sx) for the low pressure line all the way to my 95 firewall connection?

Your engine bay is clean enough to eat off of. Future goals for after things are finally working.

dbeiler · 01-22-2017, 09:32 AM

I copied this from a previous thread of mine located here: http://zilvia.net/f/showthread.php?t=633397

Quote:

Originally Posted by dbeiler

Apparently Nissan did some screwing around with the AC system components through the years of the S14. The firewall connectors changed after S14 build date 10/95. My '96 was build date 10/95 which means it falls into the early Zenki range. Most Zenkis will use the same AC lines I used during the install. Post 10/95 Zenkis and all Koukis will use different lines.

Here's another oddity. The low side line on my 10/95 S14 was slightly different from my old 11/94 S14. The firewall and compressor fittings were identical but the line OD was bigger in the 11/94. The low side line is divided into 3 pieces on both models. I could not mix and match the pieces because the 11/94 used a bigger line ID and connector fitting sizes.

Your best bet is to buy parts off a vehicle with a build date as close to yours as possible. You could also measure the connector diameter with a calipers to verify it'll fit before purchasing anything.

lagvoid21 · 01-22-2017, 07:33 PM

Quote:

Originally Posted by dbeiler

I copied this from a previous thread of mine located here: http://zilvia.net/f/showthread.php?t=633397

Your best bet is to buy parts off a vehicle with a build date as close to yours as possible. You could also measure the connector diameter with a calipers to verify it'll fit before purchasing anything.

Thanks for the info. This will save me time and headache, hopefully!

lagvoid21 · 02-15-2017, 03:00 PM

Can someone tell me what this plug on the A/C compressor is for? Mine is a single green wire, is it just ground? If it's ground, I was just going to cut the connection off and make a new one. I can't find where it connects to on my S14 since it was all removed so long ago.

dbeiler · 02-15-2017, 06:17 PM

It's the power wire to the compressor clutch coil. Ground is routed through the compressor body and the engine block. The chassis connector for that is located a few inches from the frame rail. Wiring harness runs from the brake master cylinder, down the driver's side strut tower, along the driver's side frame rail, then splits off: one connector to the power steering pressure switch and one connector to the AC compressor.

lagvoid21 · 02-15-2017, 08:01 PM

You are the best. I owe you a beer.

I followed the power steering pressure switch connector (that was joined with my MAF) sensor to the brake booster. From there the wiring is a mess. I found a snipped wire that is blue with a green stripe that I suspect is the compressor clutch power wire you mentioned. However, I referenced the FSM and if I'm reading it right, it should be a blue with a red stripe (L/R)? Am I looking at the wrong thing here?

dbeiler · 02-15-2017, 08:18 PM

If your MAF wiring was routed through the driver's side wire harness, your wiring has been heavily modified, to say the least.

The compressor clutch wire color should be L/R, yes. The blue/green you found might be for cooling fan relay 2. Do you have the original cooling fan and relays in place and operational? Also, is the triple pressure switch (mounted on the dryer) wiring intact?

lagvoid21 · 02-15-2017, 08:30 PM

Yes, it's a mess and trying to figure out what was done with my limited knowledge doesn't help.

E-fans are installed, but the triple pressure switch is in tack and wired. It's pictured in my first image attachment when I was still sourcing missing parts.

Edit: I think my best option is to run a new connection directly from the E5 AC relay at the fuse box. Please let me know if you have a more effective solution.

Thank you

dbeiler · 02-17-2017, 06:42 PM

That'll work, yes, but you'll still want to run a wire to the M63/F3 plug. The ECU needs that voltage signal to idle-up the engine when the AC compressor is running.

I would start opening the wire harness assembly to find where the wire has been cut then splice in a new extension. It'll be more effective than running new wires.

dbeiler · 02-17-2017, 06:45 PM

The AC compressor power wire must also be routed to the E-fan controller trigger to keep the fans running when the AC compressor is on.

lagvoid21 · 02-17-2017, 09:14 PM

Thanks for pointing these things out. It all makes sense in hindsight, but I didn't consider triggering the e-fans.

I read through an old A/C thread that details getting the A/C switch to actually turn the compressor on (by jumping the A/C Hand switch Y/B wire to AC Relay B/P) here:
http://www.freshalloy.com/showthread...me-on-in/page7

It didn't seem to provide clear steps to get the idle-up that you mentioned. Is there another wire to jump to get this to work? I think the A/C compressor power is actually still in the factory wiring, just the connection leading into the engine bay to compressor was removed at some point. I'll have my multimeter back Sunday so I can test continuity to find the right wire from the fuse box. I'm just not sure which plug inside the cabin they feed to.

Can you PM me your email as well? I really owe you and appreciate all your help.

01-20-2017, 08:13 PM	#1
lagvoid21 Leaky Injector Join Date: Mar 2003 Location: NoVa Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	Help with S14 A/C lines - What am I missing A/C was removed a long time ago and I'd love to get it back up in my S14 with S13 redtop SR20DET. I plan to get Codyace's bracket, but I know I'm missing lines and connections as well. I have some questions weaved into what I think I know, but please correct me if I'm mistaken. I've searched through every A/C related page I could find. 1 - What does the circled plug coming from the receiver drier connect to? Was this a connection to the stock radiator fan or an A/C component? 01.jpg 2 - The circled A/C line runs from the receiver drier towards the passenger firewall. What I circled ends there with no connection to the firewall. 02.jpg Referencing this parts diagram, it looks like line 14, but the connection at the firewall side doesn't look the same. 3795120.png 3 - The connection circled here is at the passenger firewall. This looks like what part 17 from the parts diagram would connect to. I've searched, but can't seem to find this part at all or it's name. I'm also missing part 18, the line that runs over/behind the engine. I believe part 18 is the A/C low pressure suction line. 03.jpg 4 - This is the original low pressure line for this car. I believe this connects to the missing part 17 & 18 mentioned above. It seems I need to get lines from a 1995 as well to ensure it matches up. 04.jpg 5 - The high pressure line connecting to the condenser is still in place 05.jpg Am I missing anything else besides the A/C compressor and Codyace bracket itself to complete the hardware connections? Thanks for your time!

02-15-2017, 08:30 PM	#10
lagvoid21 Leaky Injector Join Date: Mar 2003 Location: NoVa Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	Yes, it's a mess and trying to figure out what was done with my limited knowledge doesn't help. E-fans are installed, but the triple pressure switch is in tack and wired. It's pictured in my first image attachment when I was still sourcing missing parts. Edit: I think my best option is to run a new connection directly from the E5 AC relay at the fuse box. Please let me know if you have a more effective solution. Thank you Last edited by lagvoid21; 02-15-2017 at 09:26 PM..

01-21-2017, 06:40 PM	#3
lagvoid21 Leaky Injector Join Date: Mar 2003 Location: NoVa Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	WOW, thank you so much for such helpful pictures and information! I've read that the A/C lines vary between 95 and later models of the s14. The connection points are supposedly sized differently. Would you happen to know if this is true for the firewall connection point as well? Would I be able to use all the A/C lines (from a 97 240sx) for the low pressure line all the way to my 95 firewall connection? Your engine bay is clean enough to eat off of. Future goals for after things are finally working.

02-15-2017, 03:00 PM	#6
lagvoid21 Leaky Injector Join Date: Mar 2003 Location: NoVa Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	Can someone tell me what this plug on the A/C compressor is for? Mine is a single green wire, is it just ground? If it's ground, I was just going to cut the connection off and make a new one. I can't find where it connects to on my S14 since it was all removed so long ago.

02-15-2017, 06:17 PM	#7
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	It's the power wire to the compressor clutch coil. Ground is routed through the compressor body and the engine block. The chassis connector for that is located a few inches from the frame rail. Wiring harness runs from the brake master cylinder, down the driver's side strut tower, along the driver's side frame rail, then splits off: one connector to the power steering pressure switch and one connector to the AC compressor.

02-15-2017, 08:18 PM	#9
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	If your MAF wiring was routed through the driver's side wire harness, your wiring has been heavily modified, to say the least. The compressor clutch wire color should be L/R, yes. The blue/green you found might be for cooling fan relay 2. Do you have the original cooling fan and relays in place and operational? Also, is the triple pressure switch (mounted on the dryer) wiring intact?

02-17-2017, 06:42 PM	#11
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	That'll work, yes, but you'll still want to run a wire to the M63/F3 plug. The ECU needs that voltage signal to idle-up the engine when the AC compressor is running. I would start opening the wire harness assembly to find where the wire has been cut then splice in a new extension. It'll be more effective than running new wires.

02-17-2017, 06:45 PM	#12
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	The AC compressor power wire must also be routed to the E-fan controller trigger to keep the fans running when the AC compressor is on.

02-17-2017, 09:14 PM	#13
lagvoid21 Leaky Injector Join Date: Mar 2003 Location: NoVa Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	Thanks for pointing these things out. It all makes sense in hindsight, but I didn't consider triggering the e-fans. I read through an old A/C thread that details getting the A/C switch to actually turn the compressor on (by jumping the A/C Hand switch Y/B wire to AC Relay B/P) here: http://www.freshalloy.com/showthread...me-on-in/page7 It didn't seem to provide clear steps to get the idle-up that you mentioned. Is there another wire to jump to get this to work? I think the A/C compressor power is actually still in the factory wiring, just the connection leading into the engine bay to compressor was removed at some point. I'll have my multimeter back Sunday so I can test continuity to find the right wire from the fuse box. I'm just not sure which plug inside the cabin they feed to. Can you PM me your email as well? I really owe you and appreciate all your help.