Jump to content

300 Tdi strange lighting issue

Recommended Posts

I have an issue with a 1998 300 tdi 90 where the left hand sidelights fuse. if you turn the lighting switch to the first position the work fine, as soon as you move it to the second position (headlights on too) then the left hand side lights fuse.


I can't see any connection other than the switch itself unless I am being dim (pardon the pun!)? Next step would be to strip that apart I guess

Link to comment
Share on other sites

I think you could be right. Had a quick look whilst there tonight and could not get fuse to blow for sidelights. Interestingly though the left hand side front and back side lights won't come on but with the fuse out the dash lights go out


Then put hazard lights on which immediately blew the fuse. A replacement fuse does not blow and the hazards and indicators don't work

Link to comment
Share on other sites

It could well be two separate problems. Sorting out the earths so I had an earth bus at each corner plus the dash going straight back to the battery via a nice thick wire was one of the best electrical upgrades I did to my 110. This is a wiring diagram (minus the earths) I made for the standard lighting circuit on my 1988 110 which might help you figure it out


  • Like 1
Link to comment
Share on other sites

The plot thickens. I pulled all the big maxi fuses in the engine bay and cleaned those.

Disconnected the loom on the footwell of the bulkhead to the rear. Fuse in (turns out I had been checking fuse 16 not 15!) And fuse 15 for left hand sidelights blows so now I know it's front

Removed wheel and left wheel arch to disconnect sidelights,  indicator and headlight plus a relay from headlight main beam to some spotlights.

Cleaned that lot up and put back together and the sidelights now work fine. At some point in the messing about I was getting an indicator light on one side with the hazard lights switch on.

Now nothing I do results in any indicators or hazard lights. I have 12v power at fuse 1 with the hazard lights on and no power without

Link to comment
Share on other sites

Are you following the circuit diagram?

Fuse 1 is permanent live (from brown through fuse to purple) and feeds the hazard switch and the 10AS. I don't know how that can go to 0 volts without blowing the fuse.

Fuse 3 is a key selected switched feed (white) and so should be on all the time that 'ignition' is selected.

When you say "Cleaned that lot up and put back together and the sidelights now work fine.", what did you clean exactly?

Edit: The Defender Electrical Library document has a good write-up for indicator and hazard circuit logic.


Link to comment
Share on other sites

  • 2 weeks later...

I managed to find some time to go to the workshop yesterday. I decided to try swapping out the Hazard switch and the flasher relay as quick simple things before I start testing through with the multimeter

The answer was the flasher relay. Once changed everything was back to normal and working. I wish I started there!

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy