Disco 1 Dim Dip Probs

https://flic.kr/p/MEsPfp

I'm struggling with what seems to be a dim dip issue. Side lights come on as expected with my dipped on low, then when moving the stalk to dipped position the dimmed dipped lights go out with just the side bulbs on (not the dipped go to full strength).

My main beam works as it should.

I've read lots of different advice regarding the dim dip problem, I've tried disconnecting the gold resistor on my bulkhead & that stops my dipped coming on with my side lights but doesn't cure the lack of dipped lights when the stalk is in the dipped position.

I've posted a link above to my passenger footwell relays & can see 1 relay missing after the green, is this where my dim dip relay should be? I was expecting a pink relay but the carrier is white?

Any help is appreciated!!

Check out the connectors to the bulbs. These fail at about 10 years and can cause many problems.
Available on eBay for a rew quid.

Thanks for the reply Vince, I've already replaced both H4 holders with units from Halfrauds without luck. Checked & changed the bulbs - both side & dipped also without solving the issue.

As you didnt say what year it is i only guessed and checked the '96 version where there are 2 relays for dim-dip operation, K235 and K236

It certainly looks like a dim/dip resistor problem. You say that you disconnected the resistor, but did you actually connect the wires from each end of it together? in other words, removing it from the circuit by shoring it out.
I've looked at the circuit diagram and that seems to be quite acceptable.

Thanks guys, I'll take a look tomorrow. I considered linking the wires outside of the gold resistor but was a little unsure if I'd cause problems. Pretty obvious really when you think about it, I've still got to make the circuit bypassing the resistor!!!

As you may have seen from my original photo the wiring isnt exactly standard, the previous owner has cut & changed most of the wiring in the past but the photos & diagrams will certainly help.

I forgot to say my Disco is a '95 (N) 300tdi auto.

If you have disconnecting the gold resistor then you have isolated the dim dip circuit so no power to the dip beams with the engine running and side lights on.

Switching to the normal dipped beam via the lighting switch also isolates the dim dip circuit, but and in your case the normal dip circuit isn't reaching the bulbs.
So with the resistor unplugged check the voltage output with the lighting switchin the dip position from both the left side fuse 10 and right side fuse 11, if that voltage is missing it points to an iffy light switch in the dipped position.
If you are getting voltage then the next point in your checking will be both head lamps and bulb holders.

brian47 said:

It certainly looks like a dim/dip resistor problem. You say that you disconnected the resistor, but did you actually connect the wires from each end of it together? in other words, removing it from the circuit by shoring it out.
I've looked at the circuit diagram and that seems to be quite acceptable.

Click to expand...

Why would you short the resistor? The OP has proved the circuit by disconnecting the resistor

Practical experience is a lot better than just quoting RAVE on the subject.

If the resistor is in series with another load item as is the case with the dim/dip circuit, then shorting it out would prove both the external circuit and the resistor. Since the voltage on the circuit won't go over a nominal 12 volts, if the external circuit is OK, then in this case the lamps glow at their full brightness, it will also prove whether the resistor has become faulty by going open circuit.

brian47 said:

If the resistor is in series with another load item as is the case with the dim/dip circuit, then shorting it out would prove both the external circuit and the resistor. Since the voltage on the circuit won't go over a nominal 12 volts, if the external circuit is OK, then in this case the lamps glow at their full brightness, it will also prove whether the resistor has become faulty by going open circuit.

Click to expand...

As stated the op has already proved the circuit by removing the resistor out of it.
There is a dim function then there isn't... so not faulty.

discool said:

As stated the op has already proved the circuit by removing the resistor out of it.
There is a dim function then there isn't... so not faulty.

Click to expand...

Removing the resistor from the circuit will not prove either the resistor or the circuit unless it is replaced either by another known good resistor or by one having zero ohms. Leaving it out will be the same as having an open circuit resistor.

brian47 said:

Removing the resistor from the circuit will not prove either the resistor or the circuit unless it is replaced either by another known good resistor or by one having zero ohms. Leaving it out will be the same as having an open circuit resistor.

Click to expand...

The OP stated the resistor was functional. Quote "Side lights come on as expected with my dipped on low". Therefore the resistor isn't the issue.

discool said:

The OP stated the resistor was functional. Quote "Side lights come on as expected with my dipped on low". Therefore the resistor isn't the issue.

Click to expand...

Ok, I re-read the original. I'm sorry for any confusion which I might have thrown into the pot.

Listen to the relay when you operate the stalk...if you dont hear it clicking the problem might be the MFU

I can hear a relay "click" when turning on side lights & then another click when moving the stalk to dipped. It could be the same relay clicking on & off for all I know. I'll get out & check power to my fuses at lunch. Really appreciate the advice so far guys, thank you.

GlowingBulb said:

I can hear a relay "click" when turning on side lights & then another click when moving the stalk to dipped. It could be the same relay clicking on & off for all I know. I'll get out & check power to my fuses at lunch. Really appreciate the advice so far guys, thank you.

Click to expand...

Turning the side lights on on their own you shouldn't hear a relay click, unless there's been a modification to the lighting, as the only relay is the dim-dip and that doesn't switch until the engine is running, the lighting switch looks after the rest.

When you finally come to the end of your issue, unless you really like the dim-dip facility just leave the resistor unplugged, something I've done for the last eight or more years as I have LED side light bulbs and with the dim-dip on the bulbs loose their brilliant whiteness and so look a bit naff along with the dim head lamps bulb.

I see from your picture of the relays fitted to your vehicle is an early 300 series 95MY with a MA VIN number maybe, as the pic shows your vehicle has five relays the later revised 96MY has eight in two levels of four in the passengers footwel and still only one is the dim-dip relay.

Thanks Discool, you're right, mine is a '95 Disco.

I've ordered a new stalk from fleabay for £15 which doesn't seem too bad, everything else checks out so hopefully I should be sorted when it arrives Wednesday