Headlight relays - Main beam warning on, other issues

[iani]

In keeping with its usual habit of fighting me, today's foible is with headlight relay fitting. I have wired up two relays, one to take the input from the light switch (thicker blue/white & blue/red wires) and to send an output to both the headlight blue/white & blue/red terminals. If I have everything wired up the main beam warning light is always on, if I put the main beam switch on, the headlights light up, if it's off there is no light. Had enough for tonight, could be spending Xmas day on this one.

[DaveN]

Relay terminals : 

30 ........+12v (Brown)

85 ........ Ground (Black)

86 ......... Light switch (Red/Blue dip ... Blue/White main)

87 ......... light feed (Red/Blue...dip beam) (Blue/White...main beam)

So take the feed to the switch (Brown). From the switch take the Red/Blue to the first relay and Red/Blue to the dip beam lamps. Then take the Blue/White to the second relay and Blue/White to the main beam lamps.

The New (Brown if you stay with convention) feed can be daisy chained to terminal 30 of the relays. For this take a separate feed either from the battery or the back of the starter solenoid.

 Not a bad idea to fuse them too!

 

 

 

 

 

[iani]

5 minutes ago, DaveN said:

Relay terminals : 

30 ........+12v (Brown)

85 ........ Ground (Black)

86 ......... Light switch (Red/Blue dip ... Blue/White main)

87 ......... light feed (Red/Blue...dip beam) (Blue/White...main beam)

So take the feed to the switch (Brown). From the switch take the Red/Blue to the first relay and Red/Blue to the dip beam lamps. Then take the Blue/White to the second relay and Blue/White to the main beam lamps.

The New (Brown if you stay with convention) feed can be daisy chained to terminal 30 of the relays. For this take a separate feed either from the battery or the back of the starter solenoid.

 Not a bad idea to fuse them too!

 

 

 

 

 

Sounds like what I have Dave, the power feeds both have 20Amp fuses inline, the problem with this car is that the wiring has been interfered with over the years, nothing is quite what it seems. I will improve the Earth wiring tomorrow, I've tapped into an original bullet and I think I'd be better off with a fresh Earth. On the plus side, this gives me something to do tomorrow.

[DaveN]

That’s what I like to hear stuff Xmas and crack on with the car! I’m working so I’m out of it anyway, but I’ve whipped the sump off this evening to take into work to straighten it out a bit.

Yes get a good earth....often overlooked. I used ring terminals and 5 mm rivnuts.

 

[Z320]

Hi Ian,

you told us this:

"One (relay) to take the input from the light switch (thicker blue/white & blue/red wires) and to send an output to both the headlight blue/white & blue/red terminals"

So you want to switch high and low beam with one relay?

What about your second relay?

(IMO there is no need for fitting relays, it would be easyer for you to keep the electrics as they are.)

Cioa Marco

 

Edited December 25, 2018 by Z320

[iani]

1 hour ago, Z320 said:

Hi Ian,

you told us this:

"One (relay) to take the input from the light switch (thicker blue/white & blue/red wires) and to send an output to both the headlight blue/white & blue/red terminals"

So you want to switch high and low beam with one relay?

What about your second relay?

(IMO there is no need for fitting relays, it would be easyer for you to keep the electrics as they are.)

Cioa Marco

 

Hi Marco, I did say " have wired up two relays", I then meant that one carried blue/red & the other blue/white, too much wine at the time of writing for clarity!

[Z320]

Hi Ian,

if I would switch over to relays, but I will not, 

I would use the old cables to switch two relays next to each reflector, at all 4 relays.

These I would suply with voltage by new cables and from the relays to the bolbs I would also use new H4 plugs and cables.

i see no reason to do anything with the high beam indicator light.

Ciao Marco

[iani]

I've just taken all the relay wiring out and put things back to standard, all works well. I checked the relay wiring, all was correct and connected everything up, my main beams are constantly on. For now I have reverted to standard, the headlight wiring has seen better days so I've ordered two new pigtails and will try again once they arrive, I have already tried two sets of relays.

[keith1948]

There are 2 types of relay - normally closed and normally open. You should use normally open so when you operate the switch, the current to the relay switches it on and headlights should then come on. I did see once someone who had wired up a Ford Escort Mexico with normally closed relays but don't know how he got that to work. Headlights would have been always on until he switched the switch to switch them off - i.e. back to front. So power would have been on all the time through the switch - not a good idea at all.

Hello to Ciao - in the UK it is a MOT test fail if main beam warning light isn't working correctly.

Once I had a problem with my 4A. The headlamp main beam warning light came on when I pressed the horn. That turned out to be a bad earth on the horn and somehow it was earthing through the warning light. Took some time to figure that one out.

Happy Christmas

Keith

[iani]

1 hour ago, keith1948 said:

There are 2 types of relay - normally closed and normally open. You should use normally open so when you operate the switch, the current to the relay switches it on and headlights should then come on. I did see once someone who had wired up a Ford Escort Mexico with normally closed relays but don't know how he got that to work. Headlights would have been always on until he switched the switch to switch them off - i.e. back to front. So power would have been on all the time through the switch - not a good idea at all.

Hello to Ciao - in the UK it is a MOT test fail if main beam warning light isn't working correctly.

Once I had a problem with my 4A. The headlamp main beam warning light came on when I pressed the horn. That turned out to be a bad earth on the horn and somehow it was earthing through the warning light. Took some time to figure that one out.

Happy Christmas

Keith

The relays are the correct type Keith, they were from a list of parts I'd ordered to fit on an E-type I had and the list came from a very knowledgable source.

[Steves_TR6]

Relays have a standard numbering of their terminals.

87 is normally open and 87a normally closed, easy to mix up!

steve

[Z320]

3 hours ago, keith1948 said:

Hello to Ciao - in the UK it is a MOT test fail if main beam warning light isn't working correctly.

Keith

Yeah I know.

My idea is, it all works correctly if Ian sets 4 relays near the reflectors and plugs all the stuff back to the point it was.

cheers, Marco 

[boxofbits]

Hi Iani

This is the instructions I received directly from Paul at Autosparks re: wiring up 2 X identical relays for switching dipped beam and main beam, using the existing blue/white and blue/red as signal wires to each relay.

This worked for me straight away. When you switch the lamps between dipped and main can you hear the relay(s) switch in and off?

 

 

85.          This is the signal wire to trigger the relay, connect to existing dipped headlamp cable (Blue/Red, use 14/0.30)

86.          This is the earth wire for the relay, connect to ground (Black)

87.          This is the relayed output to the lamps, connect to Dipped Beam bulbs (Blue/Red)

30.          This is the feed to the relay, connect to the battery side of the solenoid (Brown) "

 

Kevin

 

 

[iani]

21 minutes ago, boxofbits said:

Hi Iani

This is the instructions I received directly from Paul at Autosparks re: wiring up 2 X identical relays for switching dipped beam and main beam, using the existing blue/white and blue/red as signal wires to each relay.

This worked for me straight away. When you switch the lamps between dipped and main can you hear the relay(s) switch in and off?

 

 

85.          This is the signal wire to trigger the relay, connect to existing dipped headlamp cable (Blue/Red, use 14/0.30)

86.          This is the earth wire for the relay, connect to ground (Black)

87.          This is the relayed output to the lamps, connect to Dipped Beam bulbs (Blue/Red)

30.          This is the feed to the relay, connect to the battery side of the solenoid (Brown) "

 

Kevin

 

 

21 minutes ago, boxofbits said:

Mine have been wired as per DaveN's above, the only difference with yours is that 85 & 86 are reversed, I don't see that making a difference?

 

[boxofbits]

1 hour ago, iani said:

 

 

Well it's possible that you have a permanent ground which will hold the lights on regardless of the state of the relay. Might be worth just swapping them over as nothing to lose?

Kevin

Edited December 25, 2018 by boxofbits

[iani]

47 minutes ago, boxofbits said:

Well it's possible that you have a permanent ground which will hold the lights on regardless of the state of the relay. Might be worth just swapping them over as nothing to lose?

Kevin

I just tried it your way Kevin, as soon as I applied power the lights came on but the light switch was off, I've reverted to normal wiring and all is well again.

Edited December 25, 2018 by iani

[matttnz]

Just clarifying here...

Main beam warning light on and switch off = no high beam

Light off and switch on = high beam?

 

As far as I can tell from the wiring diagram, the main beam warning light can only be on if the circuit is energised (which should activate the relay and the headlights seem to think so) so if it's doing that there must some DPO activity in the warning light wiring?

[matttnz]

BTW: CP or CR car iani? The circuits are a little different for the flash to pass mechanism etc.  What I can't see (unless you do have the 87/87a swapped on a 5 pole) is how it works normally through the blue/white circuit and then if you use those to energise the coil...

Argh... my brain hurts.  But that might be too much xmas yesterday

[iani]

7 minutes ago, matttnz said:

Just clarifying here...

Main beam warning light on and switch off = no high beam

Light off and switch on = high beam?

 

As far as I can tell from the wiring diagram, the main beam warning light can only be on if the circuit is energised (which should activate the relay and the headlights seem to think so) so if it's doing that there must some DPO activity in the warning light wiring?

There's certainly been some wiring changed, the ignition switch has been moved to the column and the inertia switch wiring certainly isn't original for example. The car is a  '69 CP but some parts are from a later car, I've no idea how far the mods have gone behind he dash.

[iani]

4 minutes ago, matttnz said:

BTW: CP or CR car iani? The circuits are a little different for the flash to pass mechanism etc.  What I can't see (unless you do have the 87/87a swapped on a 5 pole) is how it works normally through the blue/white circuit and then if you use those to energise the coil...

Argh... my brain hurts.  But that might be too much xmas yesterday

CP car, headlamp flash works through the headlight switch normally.

[matttnz]

B&W screen shot is of the CR wiring to show how the flash to  pass/dash switch wiring works compared with the CP (on the Advance Auto wire diagrams, colour screen shot)

P feed (fused, unswitched) gives the 12V for the flash function.  It might be that if the switch is faulty that your high beam warning (30) is grounding through that?  But that should also switch the relay feed for your high beams.  The way the light turns off when you throw the switch 29 to UW or flash to activate the P-UW link makes be think there must have been some inventive connections in the wiring up to the column to try to activate the high beams as well as the accessory lighting circuit and perhaps its earthing out through the warning light routinely and then a lower pathway through your new relays when switched.

Perhaps remove the flash to pass function first and see if things improve when the column stalk just has U/UW/UR?  As well as ensuring the warning light is through the UW circuit.  Failing that a good polish of all grounds????

[iani]

Thanks Matt, I'll have another look tomorrow, the wiring from the steering column has been messed with, the ignition was moved from the dash so there have been some extensions at least.

[iani]

I took all the relay wiring off this morning and started from scratch with yet another pair of relays (Halfords 555), I put the Dip side together first then tested the lights, everything worked fine including the mains but they were still on standard wiring. I then fitted the main beam relay and tested again, dip worked fine but when I put main beam on the dips went off and the main beam warning light stayed on. If I try using the main beam flash function nothing happens to the lights but the main beam warning light comes on. When I have the main beam selected (no lights on) I see battery voltage at terminal 86 but no output at 87. I have cleaned up all the terminals and have run in a fresh earth from the earthing point above the grille. I tried to look at the under dash wiring but it's a lost cause, a lot of the wiring has been replaced by generic wiring, all in the same colour! I notice that operating the main beam foot switch or the column switch flash fails to activate the relay, any thoughts?

[Waldi]

Hi Ian, what could help is if you draw the modifications tou made in an existing (A3 size) electric schematic; this will probably better show why the main beam is not working (but the warning light is).

Regards,

Waldi

[iani]

2 minutes ago, Waldi said:

Hi Ian, what could help is if you draw the modifications tou made in an existing (A3 size) electric schematic; this will probably better show why the main beam is not working (but the warning light is).

Regards,

Waldi

My setup is as per DaveN's post, the 2nd one on this thread. I haven't made any other modifications to the lighting circuit, I'm the victim of previous owner actions here unfortunately and I don't know what they've done other than relocate the ignition switch to the column.