17 replies to this topic

[scrippo]

Hi all,

I've tried searching, but can't seem to find my specific problem.

I upgraded my standard sealed beam lights to halogen lights, and the side lights and dipped beams work fine. When I switch the main beam lights on it blows the fuse on that circuit. I'm wounding if the current being drawn by the lights is more than the circuit can cope with.

One thing I have noticed is mini spares sell a relay kit for headlights. I have not fitted one of these, just used the cars existing wiring. Could this be the problem? Or could it be a problem with the stalk switch? I would try new ones but a new stalk is £40 and wanted to get some opinions before I shell out the cash.

Any help would be great.
Cheers
John

[hawky443]

so you have wired 2 spot lights to your main beam ?

[scrippo]

No, it's the main beams that are blowing the fuse. There are no spotlights fitted.

I did want to fit cibie super oscars at one point, but that never happened

[hawky443]

you could go to halfords and buy a relay kit , just use the wire going to a headlight to run your relay from the original switch.

just as if your wiring fogs

[jimnali]

The standard electrical circuit should be adequate even for upgraded lights. Fitting a relay (actually two relays - dip and main) is probably a good idea to extend the life of switches and ensure the headlamps receive the full voltage.

As far as I know. mini headlamp circuits were never fitted with fuses (cue Tiger99 to remind us that this is illegal) so you obviously have a wiring fault.

To help us diagnose the fault could you tell us which year and model is your car and explain what you did to upgrade your headlamps?

Also which fuse is blowing?

[scrippo]

Hey,

Thanks for the replies.

Its a 1983 Mayfair. All I did to upgrade the lights was unplug the old ones, and plug in the new ones. I think I fitted new bullet connectors in the process but it's a while since I did it.

The fuse that blows controls the horn and brake failure light switch, as well as the headlight flasher. (Fuse connecting 3 and 4 according to the Haynes) I have a correct 25 amp fuse in it before it blows! Fuse connecting 7 and 8 controls the side and tail lights but you're quite right I can't see a fuse for the dipped beams!

Cheers
John

[tiger99]

Jimnali, yes, that is correct, it is illegal to have a single fuse in the headlight circuit, although you can fuse them sepeartely, left and right. Otherwise it would be potentially lethal to have a fuse blow at night in the dark. For the same reason, I don't like single relays for main and dip, although as the laws are rarely drawn up by engineers, I suspect that they may be legal. The other utter, and totally pointless, abomination is using the same earth point for both headlights. It actually uses less wire to do it properly.

So far, I am puzzled by this one, the flasher fuse should not be involved, as it is only in circuit, as far as the headlamps are concerned, when the column stalk is in the flash posiion.

Edited by tiger99, 10 June 2012 - 10:35 PM.

[jimnali]

John
I suspect that you have a problem with dip switch on the collumn stalk. The dip switch and flasher both simply feed a voltage directly to the main beam headlight circuit (the blue and white wire). If this fuse is blowing then there must be a short somewhere on the purple wire to the flasher. If the main beam is not working at all then something has interrupted the headlamp circuit (As the headlamp is not fused then a short would have serious consequences). I would guess that these two problems are caused by something in the dip/flasher switch.

I suggest that you remove the column shroud and check for loose connections and/or broken wires. Failing that then try and trace the connections in the mechanism itself - the blue wire is the feed from the headlamp switch which switches to blue/red (dip) or blue/white (main) . Purple is the flasher feed from the fuse box.

Good luck

[scrippo]

Thanks!

Will do some searching! Will let you know how I get on. I'll be buying myself a stock of 25amp fuses as this could get through a fair few of them!

John

[JimmyB]

Was this ever resolved? I am having a similar problem in that any activation of bull beam is popping a fuse. I wondered what the outcome of your testing was.

 

Thanks

[tiger99]

I am still puzzled by this. As correctly explained by jimnali, the flasher switch just bridges the purple fused auxiliary circuit to the blue-white main beam circuit, and in the main or dip positions of the stalk there is no connection anyway. In the flash position, I can see why the fuse might blow, because if the new headlighs draw more current than the originals, it might just overload the fuse. 25A will blow the fuse in 1 second, continuous rating is about 12 to 15A, for a Lucas type fuse. The halogens will have a very high inrush current when cold, maybe 60A very briefly, and it is possible that the fuse would blow when using the flasher, but why when just using the lights?

 

I don't see how a stalk failure could cause that either, but it is not impossible.

 

I would suggest making an exact list of what does and does not blow the fuse. Try the following (engine running so you have full volts and don't drain the battery). Replace the fuse each time it blows. Hold the brake failure lamp test switch in, so you can see immediately when the fuse has blown.

 

All lights off, operate flasher. Blows?

Stalk in dip position, switch sidelighs on. Blows? (unlikely)

Now go to headlight position on light switch. Blows?

Lights off, select main beam on stalk.

Switch sidelighs on. Blows? (unlikely)

Now go to headlight position on light switch. Blows?

Go from main to dip position on stalk. Blows?

Go from dip to flash position. Blows?

 

That should cover every combination and help to pinpoint the fault.

[KernowCooper]

Slip the new units out do the fuses blow then ?

[rodandtom]

Hi,

 

Have a read of this thread http://www.theminifo...rade-confusion/

 

I think the post from KernowCooper (about the 5th post in) says it all.

 

Rod

 

RodAndTom

[JimmyB]

Thanks for your help guys, I should probably clarify my situation.

 

My original fault was a melted wiring loom starting with the permanent live from solenoid to light switch, continuing on along the blue wire from the switch to light stalk.

 

So I have replaced all the wiring and added relays and fuses to the headlamp circuit. I have four headlight relays and a horn relay now so no high current from low or high beam or horn is traveling through the switches. I have added a fuse for the light switch and also for the purple wire that powers the flasher and the horn. The light switch is a new unit.

 

- When I operate the flasher with the light switch off the 5A fuse I have on the purple wire blows, as this should be low current only to the relays this indicates a short somewhere?

 

- When I operate full beam on the light stalk with the light switch fully on the 15A fuse I have on the brown wire to the switch blows.

 

The relays all have 10A fuses in the high current lines from the solenoid and none of these blow. So it appears I still have the same fault as before.

 

I'll check the wires between light stalk and relays I guess, including the full beam indicator light circuit. I might have to rethink having a single fuse between solenoid and and light switch also. Although I would hate to melt the new switch.

 

I forgot to mention I have Halogen upgrade headlights 55/60W but these have operated fine for a year so I am not convinced they are the problem, especially now that I have the relays. The problem first started after I had replaced the choke cable and so disturbed the wiring behind the switch panel. I am surprised I didn't find any problems while replacing a large chunk of the loom.

Edited by JimmyB, 02 July 2013 - 10:20 PM.

[KernowCooper]

By any chance you dont have a bad engine earth which allowed the choke cable to provide a path to earth and heated up the steel sleeve and damaged the wiring to the headlight switch or surrounding loom?