What relay plugs in here?

[Rob Gaskin]

Well I'm still spending a couple of hours a day tracing wiring and confirming circuits (complete car). I've learned a lot, the main thing being that these cars have 'dodgy' wiring circuits. It's amazing how many joins there are IN THE LOOM from new. Colours change within the loom and I've found one connection where 4 wires join of which 3 are different colours! The circuits appear to be over-complicated.

Anyway my original question is answered:

The relay plug I asked about should indeed connect to a passing/flasher relay. There are 2 - one is on the other side of the car for some reason (2 meters of wiring)! One relay feeds power to the headlights (even with the lighting switch in the off position - as you would expect) and one feeds the earth/ground to the main beam circuit. Both these should operate when the 'flasher' button is pressed. I only had one relay and the other was 'unplugged'. I'm assuming this was done when the wiring was installed after a bare metal respray and/or when the headlights were relayed.

Thanks for your input guys - Alan and Mike were correct but probably didn't realise that there are two 'passing' relays which 'threw' me.

I'll draw the circuit - I have it in rough.

 

[Rushingphil]

Thanks for the update - very interesting!

 

[Rob Gaskin]

Diagram for those not bored by this. Standard Datsun loom 24013N3305.

Earth from passenger side (LHS) relay, batt from driver side (RHS).

Find an official diagram for this?

 

[Albrecht]

The relay plug I asked about should indeed connect to a passing/flasher relay. There are 2 - one is on the other side of the car for some reason (2 meters of wiring)! One relay feeds power to the headlights (even with the lighting switch in the off position - as you would expect) and one feeds the earth/ground to the main beam circuit. Both these should operate when the 'flasher' button is pressed. I only had one relay and the other was 'unplugged'. I'm assuming this was done when the wiring was installed after a bare metal respray and/or when the headlights were relayed.

Thanks for your input guys - Alan and Mike were correct but probably didn't realise that there are two 'passing' relays which 'threw' me.

I'm still not sure I get this. I don't see TWO 'passing relays' on any factory wiring diagram that I've looked at so far, and that includes the Japanese market HS30 types.

On the later models (including the UK market RS30 types) the factory used a six wire relay to cater for both the passing lamp function and the panel illumination dimmer control. Is your car using a loom (or an adapted loom) which is almost 'lost' between one type and another?

Here's a simplified headlamp system schematic which covers the UK market RS30 variants, and which reminds me of your schematic above:

 

[Rob Gaskin]

Hi Rob,

Here are the pictures of the two identical relays in each footwell. I guessed/assumed that they are the flasher/indicator units and have labelled them as such. However, I may be wrong as I haven't done any wire tracing yet.

View attachment 37227 View attachment 37228 View attachment 37229 View attachment 37230

Alan - like this. Unless Phil is showing the Acc Relay?

 

[Rob Gaskin]

I'm still not sure I get this. I don't see TWO 'passing relays' on any factory wiring diagram that I've looked at so far, and that includes the Japanese market HS30 types.

On the later models (including the UK market RS30 types) the factory used a six wire relay to cater for both the passing lamp function and the panel illumination dimmer control. Is your car using a loom (or an adapted loom) which is almost 'lost' between one type and another?

Here's a simplified headlamp system schematic which covers the UK market RS30 variants, and which reminds me of your schematic above:
View attachment 37366

Alan I certainly don't have a 6 wire relay. Also surely that's showing the switching between Main and Dip (Dimmer)? Instrument dimming is done via a rheostat.

I'm sure my loom is standard - have you a reference for the number I posted?

My accessory relay is connected via it's own loom (a kind of add on to my early loom I assume). That number is 24024E8200.

Anyway I'm achieving my goal and now I understand the car so much better. I've traced the rear loom too.

The circuit I drew is actual not theoretical. I've traced the wiring (by removing some wrapping and pulling wires and testing with a meter.

 

[Albrecht]

Alan - like this. Unless Phil is showing the Acc Relay?

What I'm saying is that I don't see TWO 'passing relays' on any factory wiring diagram, and I don't get why the system would need two anyway.

I think what you're calling TWO passing relays on your car might actually be ONE passing relay and one other relay. Seeing as the schematic I posted (post #44 above) for the 1974 UK market RS30 variants shows ONE relay which combines function of the passing switch and also dipped headlamps, is it possible that your car might have an extra relay which is connected to the function of the headlamps between dipped and main beam in the way that earlier cars did not?

I'm certainly no electrickery specialist, but when I see the factory doing something like adding relays or doubling up on their function, I start to imagine it was something they were trying to improve. With only one 'passing relay' on earlier HS30 types, and only one on RS30 types (and it being bigger, and having extra duties) I'd be surprised to see TWO passing relays on an interim car. These things can be difficult to pin down (and Nissan's wiring systems at the time were certainly anachronistic....) but is it possible that you do in fact only have ONE passing relay, and the other one is actually part of the rest of the dip & main beam system?

 

[Albrecht]

Alan I certainly don't have a 6 wire relay.

Yes, I know. I was trying to make the point that by 1974 the factory were adding relayed switching to the dipped and main beam circuits.

I'm sure my loom is standard - have you a reference for the number I posted?

I'll see if I can look it up in the R-Drive factory parts manuals. Stand by...

 

[Albrecht]

24013-N3305 - ASSY - HARNESS INSTRUMENT 07-72 thru 07-73 (HS30). Looks like a stock RHD Export instrument panel harness.

24024-E8200 is a little more obscure. I don't see it in either the R-Drive Export or L-Drive Export factory parts lists, and the 'E82' prefix indicates something first used/developed for the Japanese domestic RHD S30 models for 1971-on production. More specifically, it is in the Japanese market factory parts list as HARNESS - ACCELERATOR - HEAT GLASS & COOLER (superseding 24024-E4100 and 24024-E4101) and - looking at what section it is listed in - it may originally have been designed for the 'Standard' (no frills) model in Japan from '71 up, allowing a factory aircon ('cooler') unit to be installed as an extra cost option. It may then have been fitted to some RHD Export cars in connection with the heated rear window, with the extra connector for the cooler sitting like 'tits on a bull' or an 'appendix/nascent monkey tail' (take yer pick). I can see this on the Japanese market wiring schematics.

The car in question didn't of course leave the factory like this - from what you've said - so I presume this 24024 sub harness section was part of the transplant? There's lots of stuff on these cars that points the way to other variants that were going down the production line before or after them, and sometimes they sit like the Rosetta Stone, waiting for us to notice them...

 

[Rob Gaskin]

24013-N3305 - ASSY - HARNESS INSTRUMENT 07-72 thru 07-73 (HS30). Looks like a stock RHD Export instrument panel harness.

24024-E8200 is a little more obscure. I don't see it in either the R-Drive Export or L-Drive Export factory parts lists, and the 'E82' prefix indicates something first used/developed for the Japanese domestic RHD S30 models for 1971-on production. More specifically, it is in the Japanese market factory parts list as HARNESS - ACCELERATOR - HEAT GLASS & COOLER (superseding 24024-E4100 and 24024-E4101) and - looking at what section it is listed in - it may originally have been designed for the 'Standard' (no frills) model in Japan from '71 up, allowing a factory aircon ('cooler') unit to be installed as an extra cost option. It may then have been fitted to some RHD Export cars in connection with the heated rear window, with the extra connector for the cooler sitting like 'tits on a bull' or an 'appendix/nascent monkey tail' (take yer pick). I can see this on the Japanese market wiring schematics.

The car in question didn't of course leave the factory like this - from what you've said - so I presume this 24024 sub harness section was part of the transplant? There's lots of stuff on these cars that points the way to other variants that were going down the production line before or after them, and sometimes they sit like the Rosetta Stone, waiting for us to notice them...

That's interesting Alan. I can understand the use of a later harness because the car ('71) was converted to RHD with whatever was available. The 'add-on' harness for the Accessory (Accelerator - something lost in translation there) items makes sense. Good work.

 

[Rob Gaskin]

https://www.viczcar.com/forums/topic/15996-am-i-missing-passing-relays/

 

[Albrecht]

The 'add-on' harness for the Accessory (Accelerator - something lost in translation there) items makes sense.

I'm not so sure. The name seems to have been used consistently. Not saying I'm on top of all this, but would a factory aircon-equipped car not have a device/system to control idle speed between aircon Off and aircon On? I don't feel all that motivated to look into it further, but it's worth considering as a possibility.

 

[Rob Gaskin]

https://www.viczcar.com/forums/topic/15996-am-i-missing-passing-relays/

Alan did you look at this link? Do you have the diagram mentioned?

'just working on more wiring and looking at the FSM (BE section), it shows a pair of "passing relays" in line just after the light switch'.

The Accessory relay provides power to the Blower and HRW only when the ignition switch is operated in the ACC or ON positions. There is a section of 3 fuses with ACC written on the fuse box cover. It prevents leaving them on by mistake.

 

[Paul_S]

I've got a Body Electrical PDF which shows 2 passing relays:

 

[Rob Gaskin]

I've got a Body Electrical PDF which shows 2 passing relays:

View attachment 37371

That is brilliant thank you. It also shows correct rear light wiring, radio speaker etc etc. But no Blower.

I repeat BRILLIANT thank you.

 

[Albrecht]

I've got a Body Electrical PDF which shows 2 passing relays:

View attachment 37371

What market/variant/year does it apply to?

 

[toopy]

Been reading through all this with interest, but what is a passing relay anyway? Is it to do with the indicators or perhaps the headlight flash?

 

[Paul_S]

What market/variant/year does it apply to?

That's a fine question! I'm not 100% sure because I downloaded the FSM from somewhere a few years ago. It shows a LHD diagram of the dash.

The one I have is a scan of the original (you can see the print from the other side of the page in some places). BE-4 is labelled as 'Wiring Diagram' and BE-5 is 'Wiring Diagram (For U.S.A. and CANADA only).

Assuming all the different PDF sections I have belong together, the cover looks like this:


In case it's not very clear, it has P/N 20030C

 

[Rob Gaskin]

Been reading through all this with interest, but what is a passing relay anyway? Is it to do with the indicators or perhaps the headlight flash?

Come on pay attention.

When the 'pass' button is pressed a circuit bypasses the light switch (and dip-switch) and illuminates the main beams. Boy do they do it in a complicated way and as you will know the headlights work to a switched 'ground/earth'.

 

[Albrecht]

Been reading through all this with interest, but what is a passing relay anyway? Is it to do with the indicators or perhaps the headlight flash?

Momentary main beam headlamp flash, activated by push-button on the end of the indicator stalk. In Japan this was nicknamed a 'Passing' flash, hence the 'Passing Relay' name assigned to the relay which activates it.