1985 flh Ignition

[oldskool]

85 FLH Issues. Had this bike running last summer then it would run for awhile then wouldn't start. Now it won't fire. It's getting gas but I'm having spark issues.When I hit the button I got spark for a couple seconds and it goes away. This happens everything I hit the button. Everything. I swapped coil with another one. I also swapped out sensor plate. Still does the same thing .

[guido4198]

I'm also riding an '85. Mine is an FXRS that I bought new.
Let's start with the battery. I recently went through a breakdown episode myself 350 mi. from home that left me on the side of I-95 in the rain, with similar intermittent failure to yours. So far...all I've been able to determine is that my 2 year old battery was failing...intermittently. (can that happen...IDK but it's all I have to point at).
Some years ago I went through some "Starting issues". I KNEW it couldn't be due to the battery because I had a new HD gel mat battery in the bike. Whattya know...turned out the battery was bad from the manufacturer.
Just Sayin'....

[oldskool]

Forgot to mention just installed a brand new battery.

[fbn ent]

Could be the ignition module. You can check that you are getting power to it at the plug. If you can lay your hands on one give it a try and see if it clears up. There should be lots of them out there. One thing to try is jump power to the coil at the white wire. That should power the module directly.

[calif phil]

I would pull the fairing, inspect, clean and add dielectric grease to every connector you can unplug, remove any ground wire and inspect and clean the bare metal.  Those old connectors do not age well.   

[wfolarry]

Check the handlebar controls. Stop/Run switch.

[guido4198]

Forgot to mention just installed a brand new battery.

How have you verified that your "brand new battery" is not defective..??
Sorry to repeat myself, but I've been stung by taking the approach that "it CAN'T be my battery...'cause it's New".
Again....just sayin'. 

[harpwrench]

If the 85 wiring is similar to the 90 I had, they also had a power relay under the RH side cover. In addition to all the other flaky connections. You should use a digital volt meter and find all the voltage drops, and verify repairs. Adding a secondary power relay was a pretty common thing back in the day, you can likely find a write-up explaining that and why on here. Some also added a second power relay just to feed the coil, if voltage drops below a certain threshold some of them won't fire.

[oldskool]

Thanks everyone I will be back on this asap.