760 Wiper issues PLEASE HELP!

I have a 1986 764T which I have owned nearly 8 years. Last spring I
replaced the wiper blades with Bosch MicroEdge, and then the trouble
started. The wipers would be jerky, and sometimes stop or get stuck. It
sounded to me like the motor was wearing out and couldn't operate against
the increased resistance of the new wiper blades, so the local Volvo repair
shop replaced the motor with a good used one (they even said at the time
that wiper motors don't usually go bad on 7xx's). The problem is no
better. Perhaps 30% they will get stuck before moving, 40% they will move
and get stuck mid sweep, 20% they will operate ok but jerky and sluggish,
and 10% they will operate almost normally. When the problem did not get
better after the replaced motor, the shop banged around and gave it a
temporary fix. A few months later I took the cowl off and removed the
assembly, which I cleaned and lubed with wd40. It seemed better for a
couple of days, but I still have the problem. The senior mechanic who no
longer works on cars but rather runs the business thought he remembered
something like an intermittent relay causing a problem like this on these
models. I also have considered maybe a bad ground wire or similar? When
the wiper gets stuck, it doesn't drag on the power (no change on alternator
gauge) so that makes me think it might be electrical. Also, in theory, the
motor is fine, since it was just replaced. But why would the problem start
when I replaced the wiper blades, when they had worked fine up until then?

I have come to realize that problems are rarely isolated occurrences; that
others with the same model may have encountered similar problems. Has
anyone had a problem like this? This car is my "rainy day" and winter
driver, so wipers are an important feature! I realize this isn't click and
clack, but PLEASE if you have any experience with a problem like this let
me know. I am stumped.

Thanks in advance,
Patrick
Kentucky, USA

 

There was a grounding problem, and a separate ground wire was added to
the linkage near the driver's wiper pivot. Noting that the screw used
is steel, and the wiper linkage aluminum, there is usually lots of
corrosion around that connection these days. Also - WD 40 is not a
great lubricant - try removing the linkage and dipping each end into a
can of oil to get some lube into the pivots.

 

Thanks, I'll give it another try.
-Patrick

 

Did you try putting on different wiper blades?

I put some Canadian Tire Teflon winter blades, they are super quiet, $40/pair, and leave
the windshield clean after the first pass.

They are fantastic. But, regular blades would work just as well when they are new. I
have a 1987 760 GLE which gets driven in a very salted city in the winter. Luckily, I've
only had one small alternator wire issue in relation to electrical. The wipers work
great.

--
Myron Samila
Toronto, ON Canada
Samila Racing
http://204.101.251.229/myronx19

 

Mike,

Nice to see you again. Haven't checked the newsgroup for a long time. I was
gonna advice this guy to check for a sepparate condensator wich feeds this
thing, but got confused if this was on my 1987 740, wich finally died after
750K km (!) or on my 1985 245. I'll try to check Vadis, somewhere end of
next week, but if you know the answer, we might give him some easy and cheap
sollution. Both of my cars have had the problem and over here, in rainy
Netherlands, it wasn't funny at all (problem will get worse untill no wiper
function at all!)


regards, Frank v. H.

p.s. Drive a '99 V70 2.0 automatic now. Just had foglights installed today,
still looking for HU-901, RTI-nav and some other options

 

There was a grounding problem, and a separate ground wire was added

I have had about 25% wiper function this weekend (= 75% wiper
dysfunction) so I am anxious to get this fixed. Let me know what you
can find. Thanks, Patrick