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View Full Version : Is it the carburetor or an electrical problem?



IIA
07-19-2019, 06:52 PM
When my 1970 IIA idles, the battery light comes on and the amp meter goes negative. Reving the engine solves the problem temporarily. I tried adjusting the idle speed on the carburetor and that made things a little better - the amp. meter now hovers closer to zero but still a little negative. Should I just keep increasing the idle speed or does this indicate an electrical problem? I replaced the generator about 2 years ago.

mearstrae
07-20-2019, 06:01 PM
It's more likely it's an electrical problem. Check the generator for voltage output (use a volt-ohm meter- VOM), being a generator it will fluctuate in voltage between idle and higher RPM's. It might be only dirty connections in the charging system (generator wiring or battery leads). Or it might be dirty brushes or commutator. I remember my generator equipped '57 Buick's lights would dim every time I stopped (and the vacuum wipers would stop also...). Gotta love alternators and electric wipers, ahh, new technology...

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S (Gone...)

TeriAnn
07-27-2019, 10:31 PM
While both fuel system and electrical systems often have the same symptoms this one sounds like it is an electrical system, First things to check are the electrical cables. Make sure they are clean and tight. Check the battery connections, the connections to the brown wire that goes to the fuse box from the starter button (factory positive earth). The ground connectors should be battery to frame and a ground strap from the engine to the frame. Make sure those connections are tight and clean making good electrical contact. Still have problems, take the truck to an auto parts store for a free battery load test to verify a good battery and an in vehicle charging test. Its free and your hands stay clean. I ditched my ammeter decades ago for a voltmeter. It does a MUCH better job of telling you what is going on. If it is the generator not producing enough voltage you have 3 choices, buy another, find an automotive electrical shop and have their tech rebuild the generator, or if you are experienced, rebuild it yourself.