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change ecu and got a problem

67wizard

Junior Member
Have a friend that changed his ecu (thunder max) on a 05 road king. Now no speedometer and other lights in the speed o housing, also no tail lights. The brake light works fine, checked all fuses and their ok. Any and all ideas welcome. HELP.
Put the old ecu back in but same trouble. Called thunder max they neve had such a problem come up. May not be the ecu, but at a lose.
 
I could only suggest fuses or possibly the plug on the harness to ECM? All the pins straight and in line? Only other thing comes to mind is the ignition switch.
 
Make sure the fuses were checked using a test light or DVOM. Eyeballing the fuses can be deceiving.

Other than that if no codes are showing I would trace every step made during the change and use a process of elimination until the problem is found.
 
Up date all pins in ecu look good. All fuses were checked with a meter
How do you check the ignition switch? When its turned on the bike runs just fine just no idiot light in the speedo and no running light in the back of the bike. We nhave turn siginals and brake lights.
 
Thanks Tbones. I will check with the owner in the morning. I know he said he had to reset the Thundermax, other than that I don't know
 
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