Voltage ?

I got a 90 xj that I have some voltage questions about. When I check the volt. at the battery it's fine 13+ volts then when I check it on the inside fuse panel, cig lighter etc. its only showing low 11's high ten w/ the heater, lights, and stereo on. The stock gauge had me wondering. I know there not that accurate but it got me thinking enough to try and test it. So what should I try first? I think the volt. regulator is on in the altenator on these. Should I try a new alt. or something else? Thanks

XJHOX said:

I got a 90 xj that I have some voltage questions about. When I check the volt. at the battery it's fine 13+ volts then when I check it on the inside fuse panel, cig lighter etc. its only showing low 11's high ten w/ the heater, lights, and stereo on. The stock gauge had me wondering. I know there not that accurate but it got me thinking enough to try and test it. So what should I try first? I think the volt. regulator is on in the altenator on these. Should I try a new alt. or something else? Thanks

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13+ when its running and just over 12v when its not ?

Sounds right to me...

Yeah - you'll find the panel gage is notoriously inaccurate.

Nominal operating voltage is 13.6VDC, but can run from 12.5-15VDC for any of a number of reasons.

If you are seeing a significant decrease in operating voltage once you go behind the firewall, you will probably want to clean the bulkhead connector - which should be above the brake booster. I think you'll need a 4mm or 5mm socket to take the retaining bolts out. Attack it energetically with some electric contact cleaner and an old toothbrush and reassemble. You should see an increase in panel voltage.

Those connectors are packed with stuff at the factury, and it eventually gets old and causes problems. Clean it all out and yer golden.

5-90

Cool, Thanks I will try and get to it today.

Another trick would be to clean the ends of the ground strap between the unibody and engine, unibody and battery cable and the battery terminal itself. The corrison/dirt/crud build up causes the high resistance which leads to voltage drop.

Tom