Technical 8v at headlights . Please send help.

[jonjg]

Hello . Hoping someone will be able to help me as I cant pass MOT without it

Headlights are only getting 8v /9v dipped beam and are like Victorian candle lights.

Changing to 200% brighter bulbs made no difference.

Have checked:

Earth's from headlights these are fine. Added another lead from headlight made no difference.

Headlight switch getting 12v.

Checked earth from headlight switch, this is fine.

Checked earth to light relay in fusebox. This is fine.

Changed relay. No difference.

Checked all fuses. These are fine.

7.5v fuse on side of fusebox is fine.

Traced wires to relay/resistor above horn in engine bay. These are fine.

.removed wiring from here and the headlights still work dipped and full beam.

Something isn't right as I thought they would not work full beam or dipped if this was faulty? Can anyone explain what this coil of wire actually does?

Does anyone have any more ideas?

Tempted to wire a solenoid up to battery which switches 12v to lights off the switch instead.

 

[cornwall fiat]

Hello . Hoping someone will be able to help me as I cant pass MOT without it

Headlights are only getting 8v /9v dipped beam and are like Victorian candle lights.

Changing to 200% brighter bulbs made no difference.

Have checked:

Earth's from headlights these are fine. Added another lead from headlight made no difference.

Headlight switch getting 12v.

Checked earth from headlight switch, this is fine.

Checked earth to light relay in fusebox. This is fine.

Changed relay. No difference.

Checked all fuses. These are fine.

7.5v fuse on side of fusebox is fine.

Traced wires to relay/resistor above horn in engine bay. These are fine.

.removed wiring from here and the headlights still work dipped and full beam.

Something isn't right as I thought they would not work full beam or dipped if this was faulty? Can anyone explain what this coil of wire actually does?

Does anyone have any more ideas?

Tempted to wire a solenoid up to battery which switches 12v to lights off the switch instead.

was going to suggest the relay route, if only for mot.Perhapps some electrical contact spray anywhere the feed has a plug/ connector. Obviously. some resistance somewhere in the circuit.

 

[OldEngineer]

You just need to find out where the wiring is dropping from 12v to 7.5v (and you know that putting in a brighter bulb won't improve the voltage)

 

[jonjg]

Have checked all the wiring. Brand new lighting relay but for some reason I am not getting any voltage at all out of the relay (0.2v) to the fuses which then go to the dim dip wiring to the bulbs. Everything else checks out fine..have replaced all earth connections, bad fitting wire connections (green and white out of relay).
Relay does click when switching to dipped beam but still get no voltage on the grey and red wire. If I'm reading this correctly it should switch and send 12v down to the dipped beam fuses then out to the bulbs?
Does anyone know if I would be able to bypass this section of the wiring?

 

[jonjg]

May have found the issue. Although the relay is a 5 pin, the grey and white should be on number 30 which should switch. The new relay I have is wired wrong and is switching number 87 instead of 30. Will replace and update results.

 

[jonjg]

Still no 12v out of pin 30. I'm getting close to torching the car.