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MG Midget and Sprite Technical - odd headlamp problem

I recently fitted the MGOC relay kit to my 71 1275 - mainly because I have fitted halogen headlights and burned the contacts on an indicator stalk.
I'm pretty certain everything was working as it should before I installed the relays but now, the main beam flasher (i.e. pulling the lever back) only works when the lights are switched on to (at least) the first (side light) position. I'd have expected the flasher to work even when the lights are off as per my normal car (and every other car I've owned).

I can hear the relay clicking when I pull the lever but don't see the light. I've double checked all the wiring against both the MGOC instructions and others I've found online and can't see any issues.

With the lights switched on, all lever positions function correctly.

Anyone else had similar problems fitting relays into the headlamp circuit?
graeme jackson

Without seeing their wiring diagram/instructions, it's difficult to know where to start.
Dave O'Neill 2

sorry I can't help with the relays

but for the sake of balance over 4 years ago I fitted halogen headlights without relays but with a very dicky column stalk switch, I've had no problems what so ever with the headlights or even the dicky column stalk switch and I do use the dip, main beam and headlight flash

I bought a new column stalk over 2 years thinking the existing one would fall apart or stop working but it hasn't

Lucas products were a lot better made than some would have you believe and have lasted decades of use
Nigel Atkins

I dont know nigel,

Maybe jesus just loves you more then the of us.

Haha

Ive seen this senerio several times... some cars the halogens work a charm with no mods, others catch fire and burn the entire town plus the farming comunity down to the ground in under 5 minutes

I think it has to do with 2 primises

1. The quality of the hologen kit

2. The quality of life left in the cars wiring

If the kit is cheap, made in china and sold by howell and bell... that could be a problem.

if the cars wiring has been taxed to the max and over pushed , the insuation has deteriorated, harnesses hacked up, and spliced into plus general wear of time... that could also be a reason for how well hologen kit will preform


Prop
Prop and the Blackhole Midget

Prop,
I agree if the wiring and/or the switches are in poor condition then things might not work out well but that would remain the case even if you didn't swap to halogens


Graeme,
I've just had a look and there's not a downloadable wiring diagram (that I can see) on the MGOC Spares site so you may need to scan and post the one you got with them
Nigel Atkins

I've got wiring diagrams in my Haynes Manual so if you can tell me the year of your car I'll take a look.
Nick Nakorn

Hi,

If you're sure the main beam relay is clicking when you pull the switch to flash, it can only mean there is no live supply to that relay when the lights are off, ie there is no current for the relay to switch.


Where does the kit draw it's current from?



How many relays are there in this kit?



My car has relays and it works fine pulling power from the rear of the alternator on the battery live circuit.
SR Smith 1

This is the instructions for the Moss kit - I've bought one but not yet installed so cannot comment regarding the flasher operation.


http://www.moss-europe.co.uk/graphics/uk/instructions/117-515_980-369_INST.pdf

R.
richard boobier

Thanks all for chiming in.

I've kind of fixed it. First off I put it all back the way it's supposed to be i.e. no relays and it worked a charm. All functions doing what they're supposed to.
So I double checked all the relay wiring and still had no luck with the main beam flasher. The instructions state "locate a suitable power feed - we suggest using a spare terminal on your starter solenoid or fuse box). I was using position 4 on the fuse box i.e. one of the red connectors. (this is fig 10.27, page 204 of the Haynes manual).
On a hunch I moved the power to position 6 on the fuse box - shared with the greens.
Now, only the side lights work unless I turn the key. However, with the ignition on all light functions work as they should.

So, the question is, should the lights work when the ignition is off? They do when wired without the relay, however, the lights on my modern don't come on unless the key is turned (apart from the parking lights which do come on).

here is the wiring diagram from the mgoc kit..

The connections are all made behind the front grille where the main loom meets the headlamp loom.

n.b. I also tried connecting to the permanently live fuse i.e. purple, and although the sidelights and dipped headlights work normally I didn't even get a click from the main beam relay.

I'm tempted to leave it as it is now as it's working the same way as my modern i.e. from the ignition switch but it would be interesting to know if anyone has managed to get something similar working unswitched.

thanks for your interest.




graeme jackson

Looks like Richard posted while I was typing - it's interesting that the moss kit uses 85 for the earth and 86 for the main harness feed whereas the MGOC kit has the positions reversed. Does this make a difference?
graeme jackson

Ok,


It's getting clearer now.


The reds at the fusebox are the sidelights live via the switch, if the relay feed is connected here the h/lamps will only work with sidelamps on, but you will be drawing headlamp power thro the side lamp circuit.


If you connect via the green, that's fused ignition via the switch, again not good as the headlamp load is then via the ignition swotch.



Best way is connect to the brown wires at the starter solenoid or at the fusebox. That way the heavy current is not flowing via the dash switches which is the whole idea of fitting relays!


Good luck sorting this.
SR Smith 1

What would happen if you ran a secondary fuse box directly off the battrey and had your relays hooked into it...at least then it would be its own independant system

Prop
Prop and the Blackhole Midget

I have this kit on my 1275 and I ran the main power lead from the starter solenoid as recommended. One thing that worried me however was that power for both main and dipped relays went through one fuse. This means that a blown fuse will suddenly leave you with no lights at all, (except sides), I split the power lead from the solenoid, into Two feeds, with a fuse for each, this means that in the event of one blowing, you can get to a safe place on main or dipped, until you can replace the fuse.
The club were not happy with this, as driving on full beam all the time is illegal, but I pointed out that it would only be to get to a place to stop.
The original system did not have a fuse in the circuit, and the thought of suddenly being without any lights at all I found frightening.

Dave
Dave Barrow

Graeme said
"it's interesting that the moss kit uses 85 for the earth and 86 for the main harness feed whereas the MGOC kit has the positions reversed. Does this make a difference?"

No, the relay is just a coil and can be connected either way.

I'm with SR Smith on this. Take a new feed from the Brown wires but via a new inline fuse if you don't have any spare in the fuse box (which you probably won't). Did the kit come with an inline fuse? It's a bit of a corner cutting exercise if it didn't. Keeps the price down I suppose!

Out of interest, how much did the kit cost? A relay can be had for £2.61 and with a fuse built in for £6.27

Just a shame I'm not at home as I could have sorted this for you.

Best of.....
MGmike
M McAndrew

Dave...

I like your thinking, when that time comes to make this mod, im doing it your way

Decades ago they used to make a breaker switch that was used in place of a fuse, something like that would be perfect and have that breaker switch installed in the glove box . well actually 2, 1for each feed

Prop
Prop and the Blackhole Midget

Thanks all. It's my better half's birthday today so I couldn't get into the garage till after 9. I moved the relay power to the brown on the fusebox and now everything is working perfectly so thanks again everyone for the advice.
Just one question though (which will probably demonstate my total lack of electrical knowledge.... why didn't it get power from the opposite end of the brown fuse (i.e. the purples)?

Mike the kit cost me £14 but I see it's now up to £17 - and yes, it does come with an inline fuse but I think I may follow Dave's advice and split the power to the two relays with an extra fuse.
graeme jackson

" why didn't it get power from the opposite end of the brown fuse (i.e. the purples)? "

Either a bad connection or a blown fuse.
Dave O'Neill 2

" why didn't it get power from the opposite end of the brown fuse (i.e. the purples)? "



Yep, that is a bit odd, presumably if the fuse was blown, the horns and interior lamp/boot lamp, headlamp flash wouldn't be working?


And even if it did work you'er back to the old problem of all the headlamp current flowing thro one fused circuit.



Why not get a 4 way fusebox and split the loads via 2 dip and 2 main beam fuses. Tho that will involve running new wiring into at least one of the headlamp snap connectors to seperate the feeds.



Glad you've got it working properly.
SR Smith 1

This thread was discussed between 12/08/2014 and 14/08/2014

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