There 2 flasher in car one for left and right turn other for hazard flashers that one slow turn flashing down is possible changed wrong one. You turn on turn and fell top flasher to check see that one flashing. One for older 18 wheeler will slow don't they are real tall more auto one.

Your Local U-Haul Dealer Etc might be able to answer your question/concern.

1. I have connected from my rear lights to get my needed lights and noticed faster flashing w/o a problem for years.
2. I c/n remember noticing the faster flashing when there was a factory connector.
3. IMO there is something related to an overload connected at the lights vs a Factory Connector.

Look at the message-boardâÂÂs info at the link below. This explains why my truckâÂÂs rear flasher was faster and I was told that indicates a bad bulb (which was the problem).

âÂÂYour friend is right,,,the blinker relay flashing rate is based on the current draw of the circuit....more lights or a heavier current draw like hooking up a trailer would make the blinkers flash slower and less lights or a burned out light will make the blinker flash faster. LED's draw less current than the original bulbs which tricks the flasher into blinking faster as if the bulbs were burned out. The hazard circuit has more bulbs in it....both sides and front/rear... so it is less likely to be affected by a lower drawâÂÂ.

http://answers.yahoo.com/question/index?qid=20110121202753AASTliB

Here is a link that might be useful: More Info