I have trouble shooted overdrive problems with my 240s before but in those cases the up arrow indicator light was always on. I am having my daughters 240 slip in and out of overdrive but the overdrive arrow is not lit. The indicator light works because I can turn it on and off the regular way.

If the wiring to the solenoid was bad, would that cause this set of symptoms? I'm thinking that the indicator light is probably more dependent on the relay and that the wiring to the solenoid might be independent of this.

Can anyone confirm or advise on my suspicion before I get too deep into this?

Thanks
John

 

Most of the problems regarding the OD on auto trans were due to a bad solenoid or the relay.....nothing else.

How about just bypassing it? so you always have it on.

Lets say you have a bad transmission mount and when in motion it shifts where the wires get pinched or moved.....but when you are parked you turn on/off the switch the normal way and the light turns on/off just fine...

 

assuming its not an electrical control system problem.... could be a bit of flug inside the tranny where the OD solenoid goes. could be a mechanical problem with the transmission, sadly, fixing these costs more than the cars are probably worth :-/

the solenoid is powered to enable OD, and when you push the button, and the arrow light comes on, its de-powered (so, yes, its the opposite of the light). a tired solenoid, or one with a plugged port in its little actuator shaft, could easily cause intermittent problems.

 

Well, I'd prefer to just spend a couple bucks on some wire then have to buy the bypass kit. I have turned the overdrive on and off while driving during times when it would not go into overdrive and the light went on and off so I know it's not just getting pinched while driving.

Thanks
John

 

Thanks. You could very well be right. I would still like to know though if a symptom associated with a short in the wiring is that the overdrive indicator is not lit.

Thanks
John

 

that would depend on where the short is, I guess.

the light goes to a 'hot' circuit, while the solenoid goes to ground. if the relay connects them both to hot, the light is out and the solenoid is powered. if the relay connects them both to ground, then the light is on, and the solenoid is unpowered.

if the solenoid itself is defective, then no electrical fixes will work. instead of the bypass kit, you can dremel a notch into the end of the solenoid and it will act the same as if its always powered.

from what I've gathered the commonest wiring problem is with the wires to the pushbutton, or the pushbutton itself, if they go bad, they are very hard to repair, and it results in erratic or no control.