Indicators dim but hazards not

[llessur]

The indicators on my 2500 are not very bright - especially at the rear. The hazards, however, are nice and bright.

I presume this is an earthing problem so I have cleaned up the ones I can find but nothing has changed.

Are there any earthing points which are not common between the indicators and the hazards? Is there something at the indicator switch?

[Colin Lindsay]

Switch contacts would be my first port of call, if the hazards are working well then it's not an earth at the light unit end otherwise they'd both be affected so: what's different / unconnected between the two circuits (assuming they use the same flasher unit?) will be the fault, and I'd start by cleaning the switch itself; a good cleaning with something like Servisol to get years of grime and dust out of the contacts may work wonders. Next port of call will be any connectors along the circuit, and then the state of the wiring itself.

[llessur]

Cheers Colin - the indicators and hazards use separate flasher units so I will try to dig out a spare and see if that helps. I didn't realise the flasher unit could cause dim indicators though.

I'll also take a look at the switch. I do have a known good spare so I could swap them over to rule that out.

[NonMember]

It doesn't take a lot of resistance to cause two 21W bulbs to go dim. At 42W they draw 3.5A so 1ohm will reduce their brightness to not much over half. Poor contacts can easily account for more than that.

[Pete Lewis]

Make sure the flasher unit has not been replaced  by one designed to only run Led lights 

The units are normally marked as such

Seen this on a herald with dim flashers....it had a led flasher fitted

Pete

[Clive]

It may be worth using some switch cleaner on the actual hazard switch. All sorts of stuff goes on in it. (the wiring diagrams give me a headache)

[llessur]

Right, here's an update on this one.

I have fitted a new electronic flasher (definitely not an LED one) and a known good indicator stalk but the problem still remains so I have dug a little deeper.

The live feed at the indicator flasher relay is only showing less than battery voltage (about 11v) whereas the live feed at the hazard relay is showing full battery voltage.

The wiring diagram shows the live feed into the indicator relay (green and slate wire) comes through the hazard switch (it is here the circuit gets broken if the hazards are activated). I have dismantled the dash and tested the voltage of the two feeds in to the hazard switch. The feed for the hazards is 12v, the feed for the indicators is 11v.

Working back, the green circuit at the fuse box is showing only 11v (this is fed from the white circuit which I think is the switched feed from the igntion switch - both sides of the fuse are showing 11v, so it's not a fusebox related issue).

All of this is with the engine off - it is currently not running as the exhaust is off and I don't want to annoy the neighbours by starting it up without one. Not sure if this makes a difference.

I'm not an electrical mastermind so any advice welcome

[Anglefire]

Sounds like it’s the ignition switch. Check the feed to the switch - if that is normal, then keep going back until you get to the source. It might be another fused feed - I don’t have the diagrams to hand. 

[llessur]

So, I have tried two ignition switches - both show a voltage drop from the positive feed to the white (live when ignition on) circuit without the engine running. Voltages at the various terminals of the ignition switch are as follows:

• Switch off - 12.6v at the brown wire from the battery +ve feed. 0v at other terminals.
• Radio on position - 12.6v at the brown wire from the battery +ve feed. 12.6v at the white & purple feed to the radio. 0v at other terminals.
• Ignition on position - 11.3v at the brown wire from the battery +ve feed. 11v at the white & purple feed to the radio. 10.9v at white wired to ignition-switched circuit.

Is this voltage drop of 1.7v acceptable between the batter +ve feed and the white ignition-switched circuit when the engine isn't running?

Am I perhaps just chasing a non-issue that will resolve itself when the engine is running and the battery is showing 13+ volts?

I plan to get the exhaust fitted this weekend so I'll find out sooner or later I guess...

 

 

[NonMember]

That does sound more of a voltage drop than I would expect. Really, there shouldn't be a measurable drop across the ignition switch at all. However, you aren't seeing 1.7V across the switch, you're seeing 0.4V, and you haven't given enough information to say whether you're seeing 1.3V along the brown wire because you haven't quoted the voltage at the battery terminals  for the three conditions.