Ovedrive solenoid/Overdrive relay

Hi Everyone,

I haven't posted on the newsgroup for awhile, I guess it's because up to now
my 90' 765T has running great.
I am having problems with the tranny. It won't shift into 4th-overdrive
until the car has been driven for about 10-15 Minutes.
I have replaced the kickdown cable and made sure it is adjusted properly.
I just replaced the overdrive solenoid and so far no change.
I will try replacing the relay next.
Has anyone replaced the relay? Can the relay appear to work, it clicks when
cold and upshift arrow lights up, and still be bad?????
I took it out and took it apart and the solder appears to be fine with no
cracks.
Nothing happens when I deactivate the solenoid with the button when it's
cold but when it gets warm and I know it will shift the transmission will
change when the button is pushed.
When the car was cold I tried to listen for the click from the solenoid when
deactivating it with the switch, I didn't hear the click when deactivating
or activating the solenoid.
That's what led me to believe it was the solenoid because it did not click
when the car was cold.
Am I looking at a new tranny??
By the way the tranny was recently flushed and when I replaced the kickdown
cable more clean fluid was added so the fluid is nice and clean.
Any answers will be welcome.

Bernie Franklin 1990 765T 200K still running.

 

My first guess would be a broken wire somewhere if the relay is ok, though
hairline cracks in the solder can be hard to see so I always add some fresh
solder once I've got one apart.

Get the car up on ramps or jackstands, turn the key to accessory and engage
the OD (arrow light off) then climb down under and check for 12v at the wire
to the solenoid. If it's present, have someone engage and disengage it and
listen to see if it clicks.

 

James,

The overdrive solenoid is brand new and works when the car is warm only it
takes different amounts of time before it is able to go into overdrive.
Should there be 12V at the wire going to the solenoid when the car is on and
overdrive engaged (shift arrow off).
Have you ever had a relay be intermittent and still click like it is
working?
I am worried that it is the transmission itself and not the relay, which is
the last thing I yet to replace.
I have ordered one so it will be here in a few days but I have to drive on
the freeway and can't go on until I know the overdrive works properly.

Thank-you for the information James.

Bernie Franklin

 

I'd think that the 4th gear switch on the tranny wold be intermittant more
so than the relay.

I believe that the wires for the dash light and the solenoid are connected
at the relay socket so if the dash light goes on when you push the button,
the OD should work.

If the dash light does not come on until everything is warmer, the relay may
not be grounded by the 4th gear switch so no reaction would be more likely a
bad 4th gear switch.

 

I had intermittent overdrive problem. Finally traced fault to a bad
conncetion between relay & relay connector (base). Inserting the relay had
pushed the connector out underneath but was still touching the relay. We got
12v at solenoid but not enought amps to drive it properly. Took a while to
track it down too . . .

 

Thanks everyone,

As I am going out of town for the weekend using our other car I can't check
out the solutions but I will next week and let you know how it goes.
After that is a stop to the local Volvo mechanic.

Bernie Franklin

 

Yes, again it was the soldering.

It does sound like the tranny to me, if you have voltage at the solenoid
with the OD engaged (arrow off) then the problem is either the solenoid or
the transmission.

It's no problem to go 80 mph on the freeway without the OD, remember that
back in the 70's OD was an option. You'll burn a fair amount of extra fuel
though, not a good thing with what it costs these days.

 

There isn't a 4th gear switch, it was only used on the manual transmission
cars.

 

An automatic tranny, no wonder I look funny with my foot in my mouth. (
Among other characteristics.) Why is it dark in here???

Duane

 

Bless you, Duane! I was getting tired of being the befuddled one all the
time.

Mike