Skip to main content
Topic: Heritage uprated headlight wiring loom (Read 729 times) previous topic - next topic

Heritage uprated headlight wiring loom

Car is in for an mot and the tester said I don’t have side lights only headlights. This is after I fitted the uprated headlight wiring loom from heritage. It is an 91 mk2 16v with twin headlights. Is this the way it’s supposed to work. I recently changed the grill from single to twin lights and it has passed an mot since I changed them.

Re: Heritage uprated headlight wiring loom

Reply #1
The uprated loom shouldn't have any effect on sidelights.
Sidelights are small bulbs inserted into the main headlight bowls, I think the types of bulbs are listed in the Knowledge Library section under B for bulbs.

However. I suspect the issue is:

The way the mk2 is designed to work is with headlights on at a reduced amount along with sidelights. See the knowledge library for Dim / Dip resistor.

So if your Dim Dip resistor is still plugged in, and assume car is running, as it normally in when they test lights, the MOT tester would have seem the headlight bulb light up when the switch was in the sidelight position. THIS IS CORRECT AND YOUR MOT TESTER IS A MORON!

Unplug the dim dip resistor and check the side light bulbs are both active on their own, bulbs might have gone. Then plug in the resistor and look closely, you see the sidelight bulbs still light but the main headlight bulbs are also lit at about 20% strength, this will overpower then smaller sidelight bulbs and the uneducated might think there's a fault.

I hope that's your issue and a simple fix, as in nothing to fix, working as designed you just need to tell you tester he's wrong. Or present the car with the Dim/Dip unplugged if you don't want to have any confrontation.

Re: Heritage uprated headlight wiring loom

Reply #2
Sent to tester. Thanks for the reply. I know him so your moron comment we will have a laugh about !😂👍

Re: Heritage uprated headlight wiring loom

Reply #3
It says on the instructions to disconnect the ballast resistor to make sure the loom works correctly. Is that the same as the dim dip resistor. Which means it’s disconnected at present. It’s behind the offside headlight.

Re: Heritage uprated headlight wiring loom

Reply #4
Ballast resistor, dim/dip. yellow cylinder of fire.... whatever you call it, it's the same thing. and yes, at the rear of the offside light, usually lower on the chassis leg, it's where the wires go over the lip kind of under the air box where the wire sheath can get worn through and cause the short. Insulate this wire and you can keep plugged in. I like the dim yellow glow of the sidelight setting, but most people just unplug.

Re: Heritage uprated headlight wiring loom

Reply #5
So can I just unplug this resistor and insulate the connectors, because I dont need it?
16V GTI under restoration
Learning a lot  as I go along

Re: Heritage uprated headlight wiring loom

Reply #6
So can I just unplug this resistor and insulate the connectors, because I dont need it?

You can but I would still remove the wiring back to the fusebox as it can still chafe and is still live, recently happened to my old car and burnt the wiring to the main switch

 

Re: Heritage uprated headlight wiring loom

Reply #7
Thanks. Have you any idea which connector/wire I should look for at the fusebox, please? Thank you for your help. 
16V GTI under restoration
Learning a lot  as I go along