1999 Sportster LX - intermitent Electrical shutdown

[jwiatrek]

New to Forum and hoping to get some insight into a problem I have been having with my 1999 Sporster LX. Periodically, and it seems to have no pattern, the entire electical systems shuts down. The engine will die, blowers will not work, nothing at all... Then out of nowhere it seems some come back to life as if nothing has happened. The first time I took it too the shop they said they did the 'jiggle' test on the wiring under the dash and in and around the breaker panel but could not recreate it. So today it failed and required a tow for about 2 hours to get to my trailer...

Appreciate any thoughts ...

Thanks

[Ozfabs]

Start from power source ( battery ) and work your way back to dash. Remove the battery leads, clean with wire brush ( both battery terminal and wire lug ) and refit nice & tight. Do same on earth wire from battery to engine body. Maybe you have an isolator switch??? do the same with any connections on it. Check all engine multi-plug connectors. Undo them and check for corrosion or bad pins ( moisture or salt water can corrode the pins even if the plugs are meant to be waterproof ). Get into every nook and make sure you dont miss one.

Does it have a fuse box or circuit breakers. Open up the breaker/fuse box and check the connections. Fuse holders can corrode and poor electrical connection can cause open circuits.

Do same for wires and connections under dash.

If you have a multimeter then test the power wires from one item to the next for continuity eg battery to isolstor, isolator to fuse box, fuse box to ignition key switch, switch to dash, etc

Check your earths. Just because you have power going to equipment doesn't mean that its ok. I spent 3 hours Saturday midnight on a container ship tracing a bad earth in a 12v circuit.

The jiggle test can work but you must do it on each individual wire. Intermittent faults like these are a huge PITA. You may have to run the engine during some of your troubleshooting to help re-create the fault ( engine creates vibrations ).

Good luck.

Edited August 16, 2010 by Ozfabs

[tvano]

intermittent is a pia.

a low cost voltmeter will pay for itself in no time.