Electrical Advice sought

[neil4444]

Hi,

I have connected up 90% of my electrics up to my new loom (only dizzy & fan remaining) and have finally dared to connect up to the battery. As soon as I turn the key the ammeter buzzes & needle pings from central point towards discharge every few seconds. I appreciate it's nigh on impossible for an online diagnosis but does anyone have any pointers as to what may be causing this ? I thought that as it was consistently 'pinging' it may be the flasher unit but removing that has made no difference.

Cheers,

[Heuer]

Petrol pump? Clock? Suggest you take out all the fuses and replace them one by one until you have isolated the circuit. Work at diagnosis from there.

[neil4444]

Thanks David. Traced the issue back to Fuse 7 then to green wire leading to heater fan switch. All wiring looks to be correct so now suspect faulty switch.

[neil4444]

Actually, now suspecting the instrument voltage stabiliser !

[Heuer]

Easy to test - should read 10.4v on the output. Use an analogue multimeter if you can to get a stable voltage. Usually they just fail rather than give odd symptoms. There is a schematic in the upgrade Forum so you can put together a solid state version (two components ~?2) inside the original casing, if you are in any doubt.

[christopher storey]

As david said. Also, if you only have a digital multimeter, the reading of the output should oscillate between about 8 volts and 12 volts

[neil4444]

Forgot to mention (minor point !!!) as part of the re-wire I'm converting from pos to neg earth. I've looked at the JCNA guide but am unclear on whether the wiring of the instrument voltage stabiliser remains as-is ?

[Heuer]

The only thing you need to change polarity on is the ammeter (and the generator, obviously).

[neil4444]

Below is an mp4 of how my ammeter is behaving...

https://www.dropbox.com/s/97x4yi1tf5k9t ... 6.mp4?dl=0

I've traced it back to the instrument voltage stabiliser which is buzzing every few seconds. However I can't think what will be causing it to buzz. I have replaced it with another stabiliser & still exactly the same issue.

Anyone any thoughts ?

Cheers,

[Heuer]

Disconnect the VR and see if it still happens. If it does trace the wires from the VR which should only feed the fuel gauge and the water temp gauge - nothing else!