Transit Custom dipped beam fault.

[Stevesthecat]

Hi all,

My 65 plate transit custom has a fault on the n/s dipped beam as follows :

- No light and message saying ‘dipped beam fault’
- Fuses all good and bulb works on other side.
- Forscan picks up B1D00 fault ‘circuit short to ground’
- Resetting this fault clears the message on dash and dipped light works again but…..
- With ignition on but engine off the light works fine.
- When engine is running and lights switched on, after 10 seconds the message ‘dipped beam fault’ appears and the light stops working.
- Turn off and on again and this cycle repeats.

Can anyone shed any light as to what is happening?
If this is a case of taking it to a garage I want to go armed with as much knowledge as possible as to not get ripped off.

Many thanks

[AdeTuono]

Sounds like you've got a dipped beam fault.

You're welcome.

[GreenV8S]

I guess you have an intermittent short to ground on that circuit, which only shows up when the engine is running. If you can see where the loom goes, you might get lucky and spot some external damage.

[Stevesthecat]

I will follow the loom and inspect it however the 10 seconds it runs for is exactly 10 seconds every time (timed by my phone). That would be a hell of a coincidence if it was due to engine vibration.
Good point to check the loom though.

I am going to try LED bulbs to see if lowering the wattage of the bulb will have any effect as I feel it is thinking there is too much power going to the bulb causing the bcm to ‘trip’ and shut off power.

[Saleen836]

Random but have you checked all other bulbs?

Someone I know gave me a lift in his 19 plate transit and his indicator light on the dash was flashing fast (as if a bulb s blown), he said all indcators work fine and flash correctly but he has a brake light bulb blown

[Pete54]

Could be some moisture in or around the light. Unlikely the LEDs will change anything as the earth leakage is driven by voltage, not power. My old 2CV periodically loses an indicator as the earth, which is local to the light corrodes, takes about 2 minutes to loosen, roughen up and replace.....