Going along at 80mph... on I75...10 miles in...speedo and tach needle both point to zero. Security light on....Check Engine light on. 6th gear light stuck on. Odo kept working. Engine kept running perfect as before. All lights ok.

Kept going towards home and my shop. Too far to pull over and risk dead machine in Bradentucky (Bradenton, FL) ...When I got off I75....pulled over into parking lot...cycled main rotary switch....everything came back to normal. Speedo and tach ok...idiot light off...security light off...all systems ok. Rode home another 3 miles...no repeat of problem. WTF...

I have a 2010 Fatboy ....with a Tmax running the engine.
No loose battery connections. No loose grounds...no blown fuzes. No pinched wires. No DTC codes recorded by Tmax.

 

Welcome to the wonderful world of electronics.

The elves trapped inside get angry sometimes and revolt. They can do as little as a momentary hiccup, to an outright city burning riot....you can tell by the smell of the smoke.

But yeah, computers suck. I work on electronics for the Navy, and I lost track of how many times "It was doing it a minute ago though."

 

I have a 09 Fatboy with a thundermax and have had the same issue happen twice in the last year. I did the same as you cycled the ignition switch on and off back to normal. Must be a glitch with the thundermax.

 

You too huh ... dang it. Under what conditions did it glitch? How long you have the Tmax installed ... me 6 mos. What's your mileage ... mine 11k or so. Was it hot .. cold ... what lights stayed on? How fast were you going? RPM? What Speedo do you have? Factory or the HD aftermarket Speedo/Tach combo like I have .... on mine you can change the background color a million shades or some such horsepoop. Also .. my DTE reports correct miles to empty ONLY after low fuel light reports on speedo face ... go figure that one. How did your bike run during glitch? Mine ran perfect .. just no speedo/tach. What have you done to try and Sherlock Holmes this MF'er?

If we can figure this out .. would be great ... it was disconcerting to see those needles bury to zero and the CEL stay on .. I expected the engine to die at speed ... 80 mph and lots of cars and trucks in close proximity ...

I just did a through diagnostic on the Tmax ... no DTC codes ... all ok ... Tomorrow I'm gonna replace the fuze and add a dab of conductor jelly just for the heck of it ... I just checked all connections the other day when I put on new seat ... rode the thing 175 miles on Monday .. no problems. Never happened before ... but ... this is the third aftermarket speedo/tach combo ... dealer has replaced it three times cause of a "fault" with the security light.

I found a pinched connection for some aftermarket lights they threw in as part of the deal .. 20 cent connector ... and it was pinched at the fork stem .. was causing security light to go out when bike got hot ..go figure. I relieved the pinch .. reconnected the wires ... security light comes on as normal .. dealer never figured it out .. but he admitted those speedo/tach combos give them lots of trouble.

I have not had much luck with Zippers answering "off the wall" questions .. so I gave up on the Elkins Md bunch. Have you contacted Zippers? Anything from them?

 

i run a vance and hines fuel pak...
motoring down eway, check speed, says 40...
stopped at a buddys shop and wiped off trans/speedo sensor...
problem solved...
sensors/ecms/fuel tuners/ all a PITA!

 

Ok it has to be asked. Do you have a Gremlin Bell on your Bike? If not that is the problem. You need to get one.

 

definitely a TMax glitch, has happened to me 3/4 times in the last two years

i just pull the code, delete it & ride the **** outta it

Zippers knows that there's a glitch, but i don't think they know how to resolve it

 

yep, i had a tmax and the same thing happened about twice a year. No harm just annoying. TMAX told me it was a known problem that they havent been able to pinpoint. No solution to it as far as i know.

 

It happened once city driving and once on the highway. had it installed alittle over 1.5 years 14,000 KM not miles. Motor fully warmed up both times speedo and fuel gauge went to 0 all dash lights on. I have the stock speedo my DTE stopped working alltogrther after the first time i installed the Thundermax. I called Zippers and asked them about it and there response was that it is a known problem and they have no fix for it. I just figured small price to pay for the increased performance. My bike ran normal both times it happened i have had been running the Thundermax since 1000 Km and has worked awsome runs great better performance i have not noticed any difference in fuel milage only had the two small problems. I have not contacted them concerning this issue as it happened once about a year ago and i just forgot about it untill it happened 2 days ago. i am not even sure it's a problem with the Thundermax just a guess. keep me posted if you have any luck figuring it out.

 

Yup, it is a known T-Max issue. It does not effect performance, just one of the things you deal with when you are removing the MOCO's computer.