I have a 1988 coupe deville the other day my wife left the map light on and the battery died I recharged the battery and the next day this trans problem arived any suggestion or help greatly appreciated.

 

This morning I went to check the codes on the onboard comp and the battery was dead again any thoughts that this could be the problem or is it a coincadence and the battery and the shift selinoid may be bad

 

First thing to do is have a known fully charged battery in the car. How old is the battery?. How did you recharge it? overnight with a slow charge or jump start it? The map light could have been enough to cause an older battery to fail. Get a good battery in it then erase all fault codes, then report back. Make sure cable connections are clean and tight.

 

put a new battery in it how do i erase the old codes

 

I erased the codes and still have the no shifting problem goes into drive fine and reverse and it shifts down when you go to 1 but it wont manually shift up into drive when it is in drive it is not locked into first it freewheels and you have to depress the throttle to catch up with the rpm level at that time.

 

Sounds like a stripped or sticking Governor. The freewheeling off the throttle is the clue. Having the battery disconnected should have erased them. Do you still have codes??

 

Check trans fluid level when trans is hot. If it's full internal trans problem very likely. you could disconnect vac hose to modulator see if it changes anything. If it does throttle body ports carboned up.If trans shifts ok but too hard clearing carbon may correct it.

 

Thanks for the help guys I will try the va***e hose if that does not work its going up for sale car is not worth enough to spend 2500 to 3000 dollars on it is in great shape but its only worth about 1500 dollars I am told.