The relay is for Australia TCVAS

It used water temps, instead of air temps. TCVAS was disabled when engine coolant temperature was low, using this thermostat bolted to manifold side of cylinder head at the front



TCVAS is important as it reduces pollution. On the other hand if its not working performance doesn't suffer neither does fuel economy. Transmission Controlled Vacuum Advance System (TCVAS) disables spark advance except in Top Gear. Since this "retarded" spark timing reduces performance, to prevent cold-engine driving problems this system is bypassed in cold temperatures. This means vacuum advance works normally at cold temperatures. Additionally, onn the highway (in top gear) full power is always available

Top Gear Switch




Does your 1985 ute have something like this on the intake manifold? Post your pics and I will add them to the tech article

Attach file:

---

  1978 B210 TCVAS switch 20090816175554DSC08722.JPG (130.54 KB)

25230-H1604 RELAY ASSY-WATER TEMPERATURE F/WATER TEMP -7603


http://datsun1200.com/modules/mediawi ... php?title=620_Parts_Donor

Thanks cadet1200. Mine is also an '85 model, it appears to be a relay for something. There is a number printed on it 25230-H1604 a quick google and search through the forum found not much.
I'll see if I can figure it out and when I do I will let you know.

Seems to only be in the late model utes. Mine is an 85 and I have it (can’t be to important as mine is unplugged).

Problem is all the 1200 workshop manuals I have only show the earlier model wiring diagrams. I do have a wiring diagram from the internet that shows something called a ‘passing relay’, could that be it? The wire colours don’t match up though.

Plug has 3 wires going to it Black, Yellow and Blue/red

Hopefully someone can confirm.

Does anyone know what this is highlighted in the pic? It does not appear on the wiring diagram in the service manual that I have but it looks to be factory.

Attach file:

---

  IMG_0025.JPG (171.48 KB)