Help! Electrical gremlins have taken over. Accessory relay related?

[Ptero]

'73 240z. New to Datsuns.

I've got a few lights which are not working: heater controls, choke/seatbelt/fog.

Tested the lights with a battery, they work.

1st image - shows unknown yellow power and black ground disconnected which is part of a group of wires running to this gold box under the glovebox. Accessory relay? The other end of these wires follows through to the choke/seat/fog panel. I put power to the yellow and I could hear a tick sound but still no lights to the panel.

2nd image - lights for the heater controls with the ground. These also don't light up. Connected to the accessory relay as well?

How can you tell if a relay is faulty?

Initially I had a problem with the heater blower which turned out to be no power going to it. There is a loose connection for the power with no female end in sight. Still hunting down the other end or I'll have to splice into another power source.

(I would search more but it's 2am and I'm sleeeeepy)

[darom]

Ptero, you will need the 73 Factory Service Manual, electrical part, to figure out the other wires origin. The FSM shows the color codes for the wires and also the plugs location which makes it easy to troubleshoot.

You can test any relay with a voltmeter and a 12V battery.

Regards!

[240260280z]

You can get the 1973 Factory Service Manual here: http://www.hammondsplains.com/fsm/

You can get the wiring diagram here: http://atlanticz.ca/zclub/techtips/electrical.htm

[EScanlon]

Sorry Blue, the nicest thing anyone can say about the Wiring Diagrams on Atlantic Z is that they are simple.... too simple to be of any use other than to discuss grossly general terms. Just about every circuit disappears into a "magic box" and exits on another undefined wire and ta-dah you have a circuit, what happens inside the "magic box" is just that magic which is useless if you're trying to decipher things. About the only thing they're good for is to roughly identify colors.

The one true blue Datsun wiring diagram they have there is the generic 1970-ish one size fits all markets diagram. Look closely, it doesn't have an Accessory Relay, nor a Rear Window Heater. At that they have it labeled as being for the 72 Z.

The Choke Light circuitry as well as the Rear Window Fog and Seat Belt Warning system denote a specific wiring diagram with all the relays and sensors, the only thing to determine is the Automatic Transmission diagram or the Manual Transmission diagram.

But before you go into the nether studies of wiring diagrams:

The wire you mention at the Accessory Relay, the picture isn't clear enough to show the colors, just Yellow, or Yellow/White or...?

The Heater Control Panel illumination lights need the back of the panel to complete the circuit to ground via the ground wire. These lights light up when your park/headlamp lights come on. Do the other instrument lights work? If not, check your rheostat.

Just a couple things to check first.

E

[SteveJ]

Also, XenonS30 has the FSMs available for download.

[Ptero]

The blower fan was not working which needed to be fixed for safety. The original owner said, "it was working before I parked it for winter." After troubleshooting the controls, wiring and motor itself, I found out that the whole assembly had no power going to it. There was one stray wire that was loose which ended up being what powered everything else. There was no possible other connection to connect it to get power so it obviously was not working while this guy owned it. After some rewiring to get power, got it all working. HOOOOORAY!

Next task was getting the rear defrost to work. Again after troubleshooting just about everything, we ended up determining that the switch was faulty. The contacts inside the switch were corroded which didn't allow the switch to complete the connection. A simple cleaning of the contacts fixed the issue. Again, HORRAY!!!!!

Ran out of time so I didn't get around to checking the choke & fasten seatbelt lights.... besides finding out that the bulbs were dead >

[philbar73]

Hi Ptero,

Did you figure out where the yellow and black/yellow wires hook up? I have been looking for days at everything I can find it.

[Ptero]

No, sorry Philbar. The problems were fixed so I didn't bother digging further for the yellow/black wires.

[philbar73]

do your delay wipers work? I have everything working except the delay wipers.