6RA Wiring - Ignition Light On

[windsorian]

Hello,

This is my first post, so I'm hoping I am following the correct protocols.

I'm helping out a friend with the renovation of the 1973 P5B Coupe and one of the things that needs looking at is the car is not charging the battery and the ignition light is permanently on. My background is more bodywork and trim than mechanical, but I have a working knowledge of wiring, but am no expert.


Having read the various threads I found the following, which was very useful:


 roverp5.proboards.com/thread/7867/red-ignition-light-stays-on

It has given me a few pointers and I was about to proceed with replacing the alternator brushes when I thought I'd have a look at the wiring just in case anything was loose. The wiring is not brilliant, and the cord is missing or faded to oblivion on most wires, which does not help identification. However, I discovered that the C2 connector on the 6RA relay was AWOL, please see attachment.

I thought that this was the golden bullet but I fear it could be the start of some trouble. I found what I thought was the missing wire or more precisely twin wires into a single female spade terminal (it comes out of the loom in the same place as the other wires for the 6RA, see second attachment, I'm holding the end of the wire in my fingers) but not being one to take chances I wanted to check that it connected to the F+ terminal of the 11AC Alternator and the + Terminal of the 4TR voltage regulator. By using a resistance test to check for continuity on my multimeter I found that the wires connected to neither of these. Cutting a long story (and longer afternoon playing with the multimeter) I inadvertently found that the wire was connected to the ignition control (terminal 3) on the fuse board, which does not seem right. There is also a red wire connecting the ignition control to terminal 19 for the screen wash motor, which does not look original. The wires to the windscreen washer bottle are not original either so I'm wondering if a PO has tried to use the C2 connection to the washer bottle.

NB: All of the other wires appear to be connected correctly on the 6RA:
W2 - Ignition on Fuse Box (the same as the dodgy wire!)
W1 - Earth
C1 - Battery terminal Post

As I have a four terminal 4TR (two + terminals) so I'm wondering which of the plus terminals the F+ connector should connect to (the only wiring diagrams I can find are 3 terminal 4TR) or does it make a difference? I was going to temporarily connect the 11AC F+ to the 6RA C2 and the 4TR + terminals to see if the ignition light then goes out and the alternator charges the battery but need to know which terminal it should connect to (assuming it makes a difference).

Any help in putting some light on the matter (or more precisely turning out the ignition light) would be much appreciated!

Regards

Clive

Attachments:

[Phil Nottingham]

There should be a White ignition control (unfused) cable to W1 on the 6RA (W2 goes to earth). The C1 is the Brown unfused Battery contol cable. The C2 Brown/Purple goes to the F+ terminal on the alternator

The 4TR F terminal connects to Brown/Green cable on the F- on the alternator

The 3AW Warning light can AL terminal connects to the AL terminal on the Alternator. The WL terminal (Brown/Black goes to the Ignition warning light (the other terminal on the IGnition warning is a white Ignition Control cable (unfused) The 3AW often goes faulty in old age or suffers corrosion in the plug and its Black earth but is essential as is a working bulb for the alternator to charge

The Red cable is not correct (red is Sidelight colour code) the feed for the screen wash should be from the fused side of ignition via a green cable on the 10v instrument stabiliser feed ie the 12v side 

[windsorian]

Hi Phil,

Thank you for the quick reply, which is really helpful, with the exception of the C2 wire, I think the wiring on the car currently ties back to the 11AC Original scheme diagram on the following old topic (it is what I used to try to identify the wires), posted by Peter (below):


roverp5.proboards.com/thread/9893/advice-needed-starter-relay






It seems to show W1 going to earth, W2 to the ignition switch, C1 to the battery (unfused Battery Control?) and the troublesome C2 going to the Alternator F+ with a branch off to the + Connector on the 4TR.

The diagram only shows 3 terminals on the 4TR, whereas there are 4 terminals on my friend's car, so was wondering what the extra + terminal was for and which of the terminals (if it matters) the C2 wire should go to? See attached with the 4TR shown with a block connector onto three of the terminals plus a single wire going to the last one (on the left). The picture also shows the dubious red wire on the fuse board!

Regards

Clive

Attachments:

[Phil Nottingham]

W1 and W2 are just the 2 ends of the coil of the 6RA and it makes no difference which way round they are connected.

Battery control merely means direct connection BEFORE ammeter. 

The 4 terminal 4TR has a double C2 (+) instead of having 2 cables on the C2 terminal of the 6RA. This merely means the energised Battery control (feed) Brown/Purple is direct to end + terminal on the 4TR and feeds the 6RA C2 instead of feeding the C2 6RA and then to the 4TR. Not sure why Rover did it different for 1969 models on but it is the same result. 

A 3 terminal 4TR can be used but it would need a double piggyback Lucar instead of the 3-pin block plug terminal to take the single Lucar feed (Brown/Purple cable to the 6RA

Note the Rover wiring diagrams have a number of errors and not all the mods made. This was amended in later wiring diagrams

PS - is the green loop "bridge" bypassing the 3AW - if so this is definitely wrong
PPS the C2 cables may just be Brown. What is the date of registration and I am assuming as there is a White ignition control that it does not have the "Thief Proof" coil with column ignition switch

[windsorian]

Hi Phil

Thank you again for the clarification, I'm struggling to identify the wires by their colour, as they have all just faded into a pretty uniform brown colour or have lost their cotton covering completely.

So if I've got this correct, with the 4 terminal 4TR, the F+ from the alternator goes direct to the 4TR + terminal in the block connector and the single wire on the other 4TR + terminal goes to the C2 on the 6RA?

If this is correct I assume I could connect a new wire direct from the 4TR + to the C2, as it would appear that this is the connection I'm missing (I can't believe it is that simple!)?

I'm struggling to identify the green bridge cable (is it the green PVC cable on the right hand side of the fuse board in the photo?), that you mentioned, I will need to pop around and look at the car to check which cable that is and see where it is connected to and from.

The car is a late car (August 1973 I believe) and has the ignition switch on the column although who knows what's gone on in the intervenning years.

[Phil Nottingham]

Yes, you are correct in your assumptions but there must not be any green bridging cable around the 3AW as shown on the diagram. The photo seems OK from what can be seen and I think I can see the armoured cable going to the coil so it should have the column ignition switch

The wiring does seem to have been tampered with so check all connections. A 1973 car should have PVC cables not cloth covered (ours has). See if you can find the chassis number on a plate on the nearside front A post

[windsorian]

I hadn't noticed the green bridging wire on the diagram, I'm reasonably sure that there isn't anything like that on the car but will check!

I will try to get a new 6RA at the weekend and connect it up directly to the 4TR with a new wire,  if in the mean time  I get the chance, I may try to temporarily hook up a wire to the broken C2 terminal to see if that is the cure to the problem.

Having looked at different options on the forum,  I may see if the owner wants to eventually go down the Lucas A127 route to simplfy things up, especially as the current wiring on the alternator has seen better days, so might as well 'upgrade' at the same time.

[Phil Nottingham]

Many like me retain the 11AC and very reliable but for those that cannot look after them the A127 is simple and cuts all the separate components out

[windsorian]

Hello,

Its been a while but we are going to retain the 11AC (at least for now) and  finally got to replacing the 6RA, in itself a fairly straight forward job.

However, the PO has left another little surprise for us. When I removed the wire off of the W1 terminal of the old relay, I noticed a broken spade connector in it, which uncoincidentally matches the broken remains on the one from C2 terminal of the old 6RA. The battery has been connected and the engine has been run in this state (see table), so I'm wondering if there is likely to be any damaged caused elsewhere as a result? 

If I've got this right, the ignition control live wire (W2) was connected to the unfused battery control as they were connected to the W2 and the W1 respectively.

Terminal	Current Wiring on new 6RA	Old Wiring	Continuity Test on new 6RA
W1	Earth	UnFused Battery Control	From W1 Terminal to Engine Block
W2	ignition control (unfused)	ignition control (unfused)	From W2 terminal to terminal 3 on Fuse Board
C1	F+ terminal on the alternator	F+ terminal on the alternator	From C1 Terminal to F+ Terminal on 4TR
C2	UnFused Battery Control	No Connection	From C2 terminal to terminal 1 on Fuse Board

I was wondering if there is anything else I should check before connecting the battery, as it would be good to get my homework marked?

[Sam Bee]

Later cars, and certainly those of 1973, had PVC wiring. Mine is July 1973. I cleaned the wiring with WD40, as attached photo, and it came up like new so if your example has cloth covered wiring it is an earlier year - what's the registration? I also re-wrapped the loom and added relays for fog lights and electric fuel pump so don't let that confuse you

.Attachment Deleted

[windsorian]

Strangely the car is actually an August 1973 car, I have noticed it had a few inconsistencies, which I’m sure is a result of work done over the years by previous owners. It was restored at some point and there is a receipt on file for a NOS loom, so possibly an older one was fitted at some point and has deteriorated due to its age.

[Sam Bee]

If it has a thiefproof coil then this is the wiring diagramme. Note that the only difference as far as this problem is concerned is that some of the wiring has a different colour coding.

[Sam Bee]

Production finished in late July 1973 but mine was delivered just after that date, indeed some cars held in stock by dealers were registered post 1st August 1973.

[Phil Nottingham]

The 6RA relay is just a heavy duty relay to take the Field current of the alternator off the ignition switch. The Field current supplies the brushes via the 4TR regulator


You should check that activation of W1/W2 terminals close the C1/C2 to provide direct battery current.  As I explained in the long thread below poor connections especially earthing are often the trouble

The 3AW can or its connections may be faulty and this is an essential part of the regulated circuit and also controls the ignition light

[windsorian]

Thanks Sam for the diagram, the car doesn't  have the antitheft coil, so another change that has taken place during its life. I'm in awe of the state of your wiring/ fuse box, just getting the car on the road to attend a few shows this year my be the limit of the ambition but you have provided inspiration for the future.

Thanks Phil,

I checked the new 6RA on the workbench before fitting it to ensure it was operating correctly, its now wired into the car but, we've not yet connected a battery.

Having thought about it over night, I'm wondering if there is another problem in the circuits (3AW, brushes etc.) that the previous owner tried to crudely hide by moving the unfused battery control wire from the c2 to the w1 terminal. It may be just conjecture and the PO just wired it up wrong! 

The plan today, was to connect up the battery and see if the ignition light goes out , however work has gone back on hold again as the missus has tested positive for Covid, so it will need to wait.

Just as an aside, if the ignition light is still on when we connect up the battery and start up the engine, I think the brushes may be the first thing to investigate. We originally was going to inspect / replace the brushes, before we spotted the suspect wiring on the 6RA, and checked to see if we could undo the alternator bolts to gain access to the brushes. However, the front nut and bolt (not the tensioner) appears stuck pretty solid. I was wondering if there was another way to gain access to the brushes (as from memory, they are currently fouled by the rocker cover) without having to resort to a breaker bar to persuade the front nut and bolt to come undone?

[windsorian]

Just a brief follow up to say the Alternator seems to be charging fine now, the replacement relay did the trick, along with wiring it up correctly!

Thank you to those who gave some advice for you wisdom and help. I'm sure I'll be seeking it again soon!

Regards

Clive

[windsorian]

Too soon I spoke, the dreaded red light came back on.

Having found a similar topic on a P6 forum, the feedback for a 'random' charging issue, was most likely the 4TR regulator had started to deteriorate. I managed to get hold of a replacement one (sadly a Chinese import and not a NOS one) and fitted it this morning (eventually, as the screw holes don't align, which wasn't too much of a surprise) and we seem to have a charging alternator again, which is good news. Let's hope  it lasts longer than 10 minutes this time!

If it helps anyone in the future, I think the previous owner had experienced this issue and had thought the issue was the 6RA relay and had decided to try to bypass it by changing the 4TR live feed from the C2 terminal of the 6RA to the W2 terminal, thus providing a live feed to the 4TR, direct from Fuse number 2 (as opposed to though the relay closing the switch between C1 and C2 terminals) when the ignition switch was turned on. During this process they broke the C2 terminal on the 6RA, where I initially thought the problem originated. The PO work around would not have fixed the 4TR, so was a bit of a red herring and probably the issue all along was just a faulty 4TR. Time will tell if this resolves the issue longer term.

[percy]

Jun 4, 2023 12:15:53 GMT windsorian said:

Too soon I spoke, the dreaded red light came back on.

Having found a similar topic on a P6 forum, the feedback for a 'random' charging issue, was most likely the 4TR regulator had started to deteriorate. I managed to get hold of a replacement one (sadly a Chinese import and not a NOS one) and fitted it this morning (eventually, as the screw holes don't align, which wasn't too much of a surprise) and we seem to have a charging alternator again, which is good news. Let's hope  it lasts longer than 10 minutes this time!

If it helps anyone in the future, I think the previous owner had experienced this issue and had thought the issue was the 6RA relay and had decided to try to bypass it by changing the 4TR live feed from the C2 terminal of the 6RA to the W2 terminal, thus providing a live feed to the 4TR, direct from Fuse number 2 (as opposed to though the relay closing the switch between C1 and C2 terminals) when the ignition switch was turned on. During this process they broke the C2 terminal on the 6RA, where I initially thought the problem originated. The PO work around would not have fixed the 4TR, so was a bit of a red herring and probably the issue all along was just a faulty 4TR. Time will tell if this resolves the issue longer term.

[percy]

You should have checked Ebay. There's a NOS red Lucas 4TR on there now! You pay your money and make your choice. If you've bought a Chinese 4TR, you'll never be able to rely on your charging circuit again.

[windsorian]

Thanks Percy, I think that is wise advice, albeit it is a friends car, so I'll ask him if he wants to invest (I think he will have a spare in the car of most electrical parts the way we are going!)