Hi, I have an 86 tenere with electrical problems. The bike is just new to me so I am starting from scratch.

Out the other evening in the rain bike running ok when lights begin to dim then fail/faint glow. Bike still runs ok then stalls. Not enough power for starter but bike goes ok on the kick and runs sweet all the way home. Start the bike again tonight cold on the kick real easy and bike runs fine but again lights fade away to nothing after 1 minute or so.

I'm thinking maybe the alternator but maybe I am missing something obvious?

Anybody been here before?!!

Hi Tony

I would agree that the battery isn't charging (or won't hold a charge), the Tenere ignition is CDI and doesn't use the battery.

I wouldn't assume that the alternator is at fault though, the bike has old wiring, and I would give that a good look over first.

You can measure the resistance of the alternator windings with a multimeter and check they match the figure in the Clymer manual, sorry I don’t have it to hand.

Also try charging the battery off the bike then check it with a battery hydrometer, a small one designed for bikes. Check the electrolyte level first , if its very low the battery is probably scrap

The other thing in the chain is the rectifier/regulator (or is it 2 separate units, can’t remember that either), I’ve had one fail, if ignored they can destroy the alternator windings too, so defiantly worth “a stitch in time”

I’m assuming that you aren’t running a couple of spot lights and a heated waist coat, though I had no problem with heated grips

God luck

Mark

Happens to me all the time: the fuse is loose or dirty, erathing connections corroded etc. Time for an afternoon with the good old contact spray: clean all plugs in the wire harness, check all points where earth is made to the frame, clean and cover with petrleum jjelly. Sand paper comes in handy too.
Clean and grease (jelly) battery terminals.

After all that you'll be fine

Ah! Thanks for the advice people, something to start with at the weekend!

Tony