Please, someone help! - Persistently Problematic Problem

rustychassis · Apr 29, 2020

Hey all,

I've had my defender for over a decade have done thousands of miles, replaced pretty much all of it over that time and am finally stumped with a problem. So I thought I'd come to the mecca of knowledge and attempt using a forum.

I'm new to forums and one thing I see is everyone immediately tells people it's in the wrong post or thread, or someone's already written a thread. So for that I apologise if this is in the wrong place. It took me 15 minutes to find the button to write the post..

So the problem.

Due to Covid and subsequent job issues I'm now selling my truck and other toys. So to get her ready for sale I was going to sort all the little niggly bits out and get a new mot on her. One issue was the hazard lights weren't working but the indicators did.

So........ I took the dash of gave everything a little wiggle and the hazards started working, assume it was a bad connection.
However in doing so, the dashboard indicator light has stopped. So that's the problem, now everything on her works, except for that one b****d little bulb.

This is what I've done:

New hazard relay switch
New indicator relay
Checked all wiring and can't see anything lose.
Switched lightbulbs around on the back of the dash
The checked voltage going to the light bulb, it has 2 wires going to the bulb, at the same time both sides of the bulb show 8volt when then the indicator is on. I'm not an electrician but would have thought power would only be going to one side of the bulb at once.
Removed one of the wires going to the bulb, when that happens no power is going to the bulb from the remaining wire. So assume it must be creating an inline circuit, again, not a sparky.

I'm either going to pull my hair out or give up and lose a bit of cash selling her without and MOT.

Or by the power of grey skull someone on here will give me a tip that works.

Colthebrummie · Apr 29, 2020

If the wiring behind the dash of a defender is anything like that behind a series dash, it can be a nightmare tracing a fault. You need to be patient. The fault is most likely a loose connection. Have you checked the dash indicator bulb to make sure it is ok? A wiring diagram and a tester such as a multi metre is very useful in tracing electrical issues. When I bought my series 3 the hazards didn't work and it took me hours to sort them out. I had the same issues you describe, it turned out I had loosened a connector whilst my big hands were fiddling about in the birds nest of wires.

Col

rustychassis · Apr 29, 2020

Colthebrummie said:
If the wiring behind the dash of a defender is anything like that behind a series dash, it can be a nightmare tracing a fault. You need to be patient. The fault is most likely a loose connection. Have you checked the dash indicator bulb to make sure it is ok? A wiring diagram and a tester such as a multi metre is very useful in tracing electrical issues. When I bought my series 3 the hazards didn't work and it took me hours to sort them out. I had the same issues you describe, it turned out I had loosened a connector whilst my big hands were fiddling about in the birds nest of wires.

Col

Yeah switched the bulbs over and checked it's getting 8volt to the bulb

Colthebrummie · Apr 29, 2020

rustychassis said:
Yeah switched the bulbs over and checked it's getting 8volt to the bulb

8 volts, is there a resistor in the circuit then? I would have thought it should show 12v. Do you have a circuit diagram for you vehicle?

Col

rustychassis · Apr 29, 2020

Colthebrummie said:
8 volts, is there a resistor in the circuit then? I would have thought it should show 12v. Do you have a circuit diagram for you vehicle?

Col

I'd have thought that, but can't see a resistor on the diagram.

mystery · Apr 29, 2020

Check earth connections bulb relies on ground return through un-selected indicator lamps see attached circuit diagram

rustychassis · Apr 29, 2020

mystery said:
Check earth connections bulb relies on ground return through un-selected indicator lamps see attached circuit diagram

Best diagram of the electrics I've seen. I was working of the black and white one, with letters for the colours e.g LGN = LIGHT GREEN BROWN

Thanks for that.

rustychassis · Apr 29, 2020

@mystery

When finding this grounding issue. Would you say it's likely to be the relay, hazard switch or the indicator lights themselves that has a grounding issue.

How would you recommend testing? As all seem to have power running to them and from them in some shape or form.

rustychassis · Apr 29, 2020

Also, inregards to the hazard switch... where is the ground on that? I have one red and black wire that comes out the main back of the switch, then loops back around and joins to the side of the switch. Which can be seen on the diagram, but there is no wire that looks like it's an earth wire coming off it.

rustychassis · Apr 29, 2020

So I ran a wire from what I assume is the negative on the hazard switch to the chassis and sadly nothing.

Also did the same from the relay.

mystery · Apr 30, 2020

the earth shown could be the actual switch body any pict 's of said switch I assume the indicator work and the hazard are working so eliminating the flasher relay and hazard switch

rustychassis · Apr 30, 2020

mystery said:
the earth shown could be the actual switch body any pict 's of said switch I assume the indicator work and the hazard are working so eliminating the flasher relay and hazard switch

Everything works, except for that damn little bulb on the dash. New relay, new switch.

I'll get a picture of the switch later today.

Dippypud · Apr 30, 2020

rustychassis said:
Everything works, except for that damn little bulb on the dash. New relay, new switch.

I'll get a picture of the switch later today.

Does the bulb light on bulb test ?

Colthebrummie · Apr 30, 2020

Try a temporary earth wire to the dash bulb.

Col

rustychassis · Apr 30, 2020

Dippypud said:
Does the bulb light on bulb test ?

Don't think it ever did, but well I never noticed any lights come on when I start her. Just red and orange lights. No green or blue lights.

rustychassis · Apr 30, 2020

Colthebrummie said:
Try a temporary earth wire to the dash bulb.

Col

I'll try it, but assuming it does work if I rig a ground directly to the bulb, I assume that shows the bulb is working, the bulbs getting power, but there is still an earthing issue. How would I find the earthing issue as everything seems to be working except for that bulb.

mystery · Apr 30, 2020

try removing bulb holder and apply 12 volt to contacts to confirm bulb is correctly fitted in holder .put a volt meter on each of the two contact pads and ground that the bulb holder locates on circuit board to confirm you are get 12 v when indicator are on in to confirm p c b is OK

rustychassis · Apr 30, 2020

mystery said:
try removing bulb holder and apply 12 volt to contacts to confirm bulb is correctly fitted in holder .put a volt meter on each of the two contact pads and ground that the bulb holder locates on circuit board to confirm you are get 12 v when indicator are on in to confirm p c b is OKView attachment 207558

I'll give it a shot. Worth trying anything at present but I'm drawn to the conclusion it's not the bulb as I've switched it for working bulbs (and holders) already, e.g switched it out with the oil bulb and holder which I know is working. When switching the bulbs and holders around, the oil light continues to eliminate but the indicator one still doesn't do anything.

Dippypud · Apr 30, 2020

rustychassis said:
I'll give it a shot. Worth trying anything at present but I'm drawn to the conclusion it's not the bulb as I've switched it for working bulbs (and holders) already, e.g switched it out with the oil bulb and holder which I know is working. When switching the bulbs and holders around, the oil light continues to eliminate but the indicator one still doesn't do anything.

There may be a crack in the circuit feed, have you checked the board closely ?

mystery · Apr 30, 2020

are you get 12 v on the bulb contact pads and visually look for any signs of corrosion or contact face being damaged and also the plug contact areas

Please, someone help! - Persistently Problematic Problem

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