OD Relay soldered, now UP arrow on dash is on

Hi guys! It's me again with the latest in the saga that is my 1989 740
Turbo A/T.
Remember when my top gear went out and a new OD solenoid was
recommended? We put one of those on and then the OD started working
again, but alas, intermittently. It hasn't come on at all in the past
week or so. Good thing I only use the car for in-town driving and I
live very close to work.
Today I soldered the OD Relay and now the "UP" arrow on the dashboard
is on and I can't get it to go off.
Also, there's a horrible high-pitched whirring sound that kicks in at
about 40mph/2,300rpm.
As always, any assistance would be greatly appreciated.

 

Are you sure you didn't accidently bridge two joints in the relay?

Not sure what the whirring sound would be, I doubt that's related to the
relay.

 

(92 wagon)

Posted a similar problem a while back. Stuck in overdrive. Solenoid
was totally shot and replaced. Relay checked and ok. No problem with
up arrow light. So everything outside of transmission apparently
working.

Last resort was power flush. Took to dealer, asked to watch beginning
of fluid drain before flush. Saw fluid come out, about 3 quarts(?) It
was still red, though not bright red as new. Saw no black gunk, metal
bits, etc. Dealer suggested not doing power flush because 1) they
"sometimes may break things" during flush on older car and 2) fluid
was very much cleaner than we expected.

Replaced 3 old quarts with 3 new quarts. About 2 weeks later
overdrive started to "unstick" at about 55 mph. Has now been
unsticking more frequently and starting at about 40(?) mph.

Am going to change out 3 quarts transmission fluid every 5,000 miles
along with engine oil from now on. May be overkill, but short money.
Why is engine oil changed so frequently and not transmission fluid?
Doesn't make sense on something with so many moving parts.

 

Both lubricate moving parts, but engine oil gets contaminated by
combustion gases.

 

There's a LOT more dirt created in the engine from burning fuel, and the
operating temperature of many parts is substantially higher. Changing
the transmission fluid is a good idea, but every 30k-50k is more reasonable.

 

For your car the ATF should be flushed/replaced every 30,000 miles (Volvo
recommendation).

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

Agreed. I plan to change 3 quarts per service only. Fully flushing it
out will depend on what my mechanic says about what may break as the
dealer put it. My mechanic doesn't have the power flush machine. Have
to go to a dealership for that, or god forbid, a national chain
transmission shop.

 

If you just drain the pan about 2 quarts comes out. You can also
replace all the fluid at one time (sort of a power flush) by hooking up
a 1/2" clear hose to the top trans cooler line at the radiator, put
the other end in a gallon container and run the engine about a minute
at a time. stop the engine after about 2 quarts of fluid comes out. Top
off and do it a few more times until the new fluid starts coming out.
Takes about 9 quarts to do it this way.
I did it on my 89 740T I bought used with 179K miles. The 2 quarts from
the pan came out pretty clean but the rest from the flushing method was
somewhat redish/brown and a bit murky. Shifted much smoother
afterwards. HTH

Dave