['78 Factory A/C Relay Wiring Questions]

 

On 9/19/2018 at 7:47 PM, TheWeekendWagon said:

 

Well you would think I would be able to figure it out, but I am either reading the wiring diagram wrong or not understanding how that particular factory relay works.

 

From what I can tell LY originates at the fuse block so I would think it was power. Here's the wiring diagram for the A/C circuit...

 

 

Thanks Weekend Wagon!  Your diagram really helped me to hook my electric fans to come on when I turn on the AC.  Living in AZ it's a MUST!  I've attached your diagram with a circle where I connected my green wire to the L (blue) wire for the compressor magnet clutch.

 

Electric Fan to AC Connection.PDF

[Tachometer illumination issue [Solved]]

Forgot to mention the Dash LEDs.  I went with Ice Blue and they are plenty bring, and the stock dimmer tones them down a bit if wanted, however, they aren’t bothersome on high so I’ll skip installing the PWM switch. (I was just wondering if it was necessary).  We’ll see how the Hazzard’s work once the new fuse blocks are in.  The original block is rusted, corroded and 3 have only 3 prongs.

[Tachometer illumination issue [Solved]]

Thanks again for the info.  I’ll be installing 2 Blue Sea (5035) Blade Fuse blocks - 1 for the 24 hour side and one for the accessories/switch side. I’ll add an in-line fuse for the radio for the 7th (13th) fuse on the accessory side.  The ability to use “jumper terminals will allow me to mimic the original fuse layout perfectly. There’s a good video on YouTube which seems to make it fairly simple.

[Tachometer illumination issue [Solved]]

On 6/16/2020 at 9:38 PM, Oblithian said:

Glad my confusion has helped someone.

Oblithian - A Great Big THANK YOU for taking the time back in July 2018 to solve what looks like one of the biggest mysteries of the Z LED issues.  I just purchased a ‘78 280Z a couple of weeks ago and am getting the wiring all squared away while tackling the instrument lighting.  The car itself is in Great shape both inside and out, however the old fuse block is corroded and has 3 fuse holders with a prong missing.  I have ordered a new Blade Fuse block (Rear Terminal ATC ATO Fuse Block Bussmann 15712-14-06-21A) and will replace over the old glass fuse block in the coming days.

 

Question: Did you find the need to replace the Rheostat Dimmer Switch With a PWM switch due to the LED’s or not necessary?

 

Question: My HAZZARD switch may either be shorted or simply “gone bad” - when I press the hazzard switch it immediately makes my voltage meter in the dash go to 0.  It takes some time but then the voltage meter resets once I turn off and then renegade the electrical by turning the key.  However, sometimes the HAZZARD switch actually works.  Any Thoguhts?

 

If I need to get a new hazzard switch, do you have any ideas where I might be able to find one?  Google searches are coming up BLANK for OEM switches.

 

Thanks!!!!!!!!!!!!