Electrical issue with 80 Series

[Tekaposam]

Hi everyone,
I have a '96 80 Series 4.2 diesel turbo. Great truck but have really strange thing going on with the electrics.
Every now and the relay that controls the dash display lights and tail lights fizzes and then they all go out. Flicking the headlight control stalk sometimes gets them to come back on. Sometimes the same lights go out when the foot brake is applied!
I have replaced the relay a couple of times, replaced the batteries but it still happens occasionally.
Because it is intermittent, it is difficult to get anyone to give me a diagnosis.
Does anyone have any suggestions?
Cheers
Sam

 

[StarCruiser]

Hi Sam and welcome.
Sounds like you have a loose connection somewhere. I agree, intermittent faults are a pain to find.

Try putting all your lights on then go round wiggling things, relays, wires etc. and see if you initiate the problem. Pull relays and check for burned contacts as I have a feeling there is a known problem with that on the headlights. Also check your fuses are well in and don't have any burned or corroded contacts. Finally If i remember there may be a stalk problem that may affect it. Check earth connections and those to the rear of the instrument cluster (unlikely as it is the feed to the relay that makes it buzz).

Good luck with it. Others may have more specific info.

Best wishes
Richard