Hi everyone. I just bought a 91 740 wagon with 145k on it for 700$. It is in really good shape, body-wise, but has some quirks. For starters, and the most annoying thing is that the windshield wipers don’t work. The washer sprays the front windshield, but it won't wipe at all, and the rear wiper doesn't spray or wipe. I noticed that some people have had luck getting them to work by wiggling the key, but that doesn't work for me. I also have a miss/lope at idle that smooths out once I give it more throttle. The plugs and wires were recently replaced, as well as the t-belt, but the cap and rotor were not replaced. Any ideas where to start looking to get the wipers going again, asap?

 

Welcome! You're going to need a few things with which to work on your Brick. One of the most valuable things is a digital multi-meter. Sometimes, a test light alone is sufficient. I believe the washer motor and sprayer pump are on the same fuse, but I'd still check the fuses first. The second thing I'd look at is to see if power gets to the wipers when switched on. If there is power then the motor may be shot. If no power then I'd look at connections between the stalk and the wiper. There is a relay on that circuit but I think it is only for the 7 second delay...would need to research that further...If the wiper motor can be heard running, then obviously there is something not right with the wiper linkake.

 

Thanks for the advice. Would you happen to know which pins to probe in the motor connector? I don't know if this is related, but like the other ones I've read about I also have no horn when pressed, and the SRS light is on constantly. I've heard that those all seem to go out with the ignition switch, but I have no idea. This is not only my first Volvo, but it is my first non-domestic car I've ever owned...I don't want to get off on the wrong foot..

 

Offhand, I don't know which pins but...don't probe the motor connector. Just use a test light and probe the connector that attaches to the motor. Turn the wiper switch to on and probe one slot at a time with the test light well grounded.
I doubt the ignition switch is bad...you really don't have the miles for it but...if it were driven exclusively on many short trips during its life I suppose it is possible. First, I'd pull the SRS codes...this should get you started...

 

Thanks. I'll check that out tomorrow before work. I had another question: what is the hole in the exhaust pipe for before the catalytic converter? I just removed a menagerie of soup cans that were hose clamped to the pipe because of an exhaust leak, drilled out the cat flanges and put bolts in the flange and reused the old gasket, but there's about a 1/2" hole in the pipe with nothing going to it and as far as I can tell it is original and likely should have something going into it or attached to it, maybe an o2 sensor?

Any thoughts on the miss at idle?

 

I believe some models had an O2 sensor before the cat and some had the O2 sensor in the cat. Assuming your O2 sensor is in the cat then this hole should be plugged. As to the miss try pulling one plug wire off at a time . The wire where it doesn't make a difference would be the problem cylinder. That being determined then check the spark plug , the wire and the dizzy cap and rotor. Also check the compression in that cylinder. That's where I would go.

 

Ok thanks. I'll check that out.
Well, another question...WHERE is the wiper motor? It's not against the firewall, so I can only assume it's buried somewhere under the cowling. I'm sure I have to pull the wiper arms, but where do I go from there? How does the cowling come off? Or would it be more beneficial to check the switch first before doing major disassembly?

 

You are correct, the motor is located under the cowl but don't despair...it is child's play to access. Remove the wipers and three bolts and is off the car. These pics are of a 91 740 cowl and wiper mechanism so it's exactly what you will find. The engine bay shots are of a 90 model which also attaches exactly the same.
The cowl attachment points...
overview

passenger attachment point

driver side

center (this tucks behind the firewall, all you see is the bolt)

Here's what you see under the hood...
passenger side by hinge

driver side

center bolt, just under the bay light on firewall

close up

The cowl has forks on the side edges that hook to hold the rear and sides down. After removing the three bolts, pull forward and slightly up...


The wiper mechanism is self contained and looks like this...

On the driver side of the assembly is a gray connector. That's where you check for juice.

And, yes, I'd check the switch first. But, as you can see, removing the cowl is really not tough...If you find your motor is bad, it's simpler to swap out the entire assembly...the one in the pics is available should you need one.

 

Thanks a lot! I will definitely check that out later. I am a mechanic, but have literally no experience with european cars... this car looked so ridiculously simple to work on when I bought it and hopefully I don’t change my mind about that.

Thanks again for all the help!

 

Oh..it is simple. The first Volvo I popped the hood on freaked me out. Stuff that should be round was square, stuff that should be mechanical was electric and vice versa. Once I sat down with a shop manual and read it cover to cover as if it were a novel, I was not only impressed, I was ready to start digging in!! Happy hunting!

 

If it does happen to be the wiper switch and not the motor would I be able to swap in a switch that doesn't have the rear wiper control? I went to check out the rear wiper and it looks like the trans or motor are completely disconnected...I can move the wiper up and down by hand... so i'm thinking the rear wiper hasn't worked for some time, but again, like I said the front washers squirt, but no wipe.

 

Either will fit; I believe there is just one less connection for the sedan version.

 

Well, I messed around a little with the motor last night and NOW it works. I was pulling up on the arm to see if the motor would work with a little persuasion, and with a little persuasion it struggled to wipe, BUT moved. I ripped off the arms and the cowling and gave the armature end of the motor a gentle tap with a hammer with the switch on and then the wipers started working perfect. I gave the motor case seams, and the wiper trans linkages a light soaking with some liquid wrench, and then some knock-er' loose, and turned the wipers on about 50 times with no troubles in any speed. Then I let the motor/wipers run for a solid 10 minutes with the motor showing no sign of weakness, all the while lubing up the linkages.

SO, I have it figured out anyway, and hopefully should have enough time to get a replacement motor if the mood should strike me.
AND thanks again everybody!

 

Now it's time to get some new wiper blades and work on that miss... the kid I bought it from said something about the transmission mount being bad, but really all a mount will do is make you feel the miss even more, from my experience. And I have to change the trans fluid and filter...it's pretty brown.

 

Does anybody know how much of a pain it is to change the trans fluid? I also know it says in the owners manual to use DEX/MERC II trans fluid, would I be safe to use MERC-V? I have almost a whole case of merc-v synthetic that i'll probably have little or no use for in the near future.