lionel 90 degree crossover problems O scale

[Pecka]

Hi, 

I am relatively new to model railroading, having just started restoring my grandfathers Lionel 671 locomotive and cars.  I have all my wiring issues sorted except every time my train goes over the 90 degree crossover, the e-unit switches to neutral.  I switched it to forward only and it goes over fine though.  I double checked the track connections and they seem clean and tight.  The problem happens when the front roller leaves the middle rail to roll over the plastic part in the middle of the switch.  I have a second 90 degree crossover and tried switching that one in but I get the same result.

Any thoughts would be appreciated.

Thanks

[ADCX Rob]

You've already done some good testing.

The rear roller is the problem!  Clean it, check for continuity between the two rollers,  clean the track, and report back to let us know how it's going.