Weird electrical problem. 1999 FXR2
Thread Starter
|
4th Gear
Joined: Oct 2014
Posts: 8
Likes: 1
From: California, USA
Weird electrical problem. 1999 FXR2
I went to remove the top bolt that holds the oil tank in place. When my wrench touched the bolt and the frame at the same time there was a small spark. I grabbed a multi-meter and tested for voltage. From battery - to the tank there is zero volts, from battery + to the tank there is 6vdc!!! The oil tank is (should be) electrically isolated. The mounts are rubber well nuts, so no metal is touching the frame of the bike and my oil lines are rubber.
Any ideas as to what could be happening?
Edit- I also tested from the tank to the frame ground and it shows 0 vdc, so this really makes no sense.
Any ideas as to what could be happening?
Edit- I also tested from the tank to the frame ground and it shows 0 vdc, so this really makes no sense.
Last edited by HarleyDavidsonFXR2; Dec 4, 2019 at 10:33 AM.
Depending on the carbon content in the hoses and the fluid, you will see a voltage reading when touching the positive cable to a hose. I can go out to my car and get from 6-12V (but no real current) from the battery positive to a cooling hose. As an aside, marine hoses have a high carbon content for bonding (grounding) and preventing galvanic corrosion. The tank is connected to the hose.
I couldn't tell you about your spark, but if you want to have some fun, take your meter out to your car and go from battery positive to coolant lines and see the readings. Try it on the bike too.
Just because your tank might not be bolted to the frame, doesn't mean it isn't more negative than the positive post due to the connections and fluids it shares with the block. You shouldn't get a spark from that though. On your bike, I would be verifying all your grounds for being clean and tight.
I couldn't tell you about your spark, but if you want to have some fun, take your meter out to your car and go from battery positive to coolant lines and see the readings. Try it on the bike too.
Just because your tank might not be bolted to the frame, doesn't mean it isn't more negative than the positive post due to the connections and fluids it shares with the block. You shouldn't get a spark from that though. On your bike, I would be verifying all your grounds for being clean and tight.
Last edited by Ed Ramberger; Dec 4, 2019 at 01:30 PM.
Club Member
Joined: Jun 2007
Posts: 45,429
Likes: 2,898
From: Bedford UK
Ed makes a good point - a bad ground will persuade your electrics to find a new way back home! I suggest you start with checking and cleaning both ends of your battery ground cable and work from there.
Thread
Thread Starter
Forum
Replies
Last Post
laserman2431
Sportster Models
6
Jul 18, 2012 07:49 PM
