My 2002 Ranger has a 5 speed electronic shift Transmission. Recently a rear turn signal bulb burnt out. I grabbed the wrong one at Autozone and had my wife go ahead and drive for a few days until I could get the right one. Well the trans started shifting really hard almost as if the vacumm modulator was out (on older transmissions) The O/D light came on and wouldn’t shift out. I put the new bulb in and the trans corrected. The fluid was burnt and I serviced it with a new filter. What caused this? Any ideas?
Take it to a transmission repair shop. The wiring may be crossed, etc. Normally, the turn signal circuit is not connected to the transmission control circuits.
If the transmission fluid smells burned, it should be changed. It has mileage/time to change the automatic transmission fluid and filter, and other drive line fluids, now.
I already changed the Fluid ( 4 qts is all you can get out) and installed the new filter. I thought I would drive it a week or so and drain out 4 qts and replace that. I hoped that maybe if I siphon the fluid out this way until the fluid looks right, I would be OK.
I changed my coolant also and of course the oil and filter.