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Washer Pump Repair and wiring


Active member
Dec 1, 2021
My !983 245 has both washer pumps not running. I did a voltage check on the terminals going in and there's proper power being sent. There's fluid in the reservoir of unknown vintage (blue).

Windscreen pump has ~4 ohms of resistance across it but wasn't running. Terminals were very stuck to the plug, one actually pulled out of the plug somewhat when removing it. Wires leading to the plug are super crumbly and need replacing (or I just wrap in electrical tape). Looks like they're crumbling deeper into the combo-wrapped wiring bundle.

Rear pump (ironically further forward) has 5 MOhms of resistance, so I assume that one is completely burnt out. Wires are in slightly better shape but still crumbling like crazy.

I watched David Bello's video about the components here https://www.youtube.com/watch?v=-vpv4zijcDE and still have a few questions

1. Is 4 Ohms expected resistance such that if that pump is not running it's likely stalled?
2. Flushing the lines - I assume there's all sorts of old crud in the lines, beyond using compressed air, what are suggested fluids for flushing? (Push a bunch of alcohol or something in, let it sit, push it out, repeat...)
3. Anyone found any problems with MTC's pump?
4. It looks like I can get replacement plug + wires but it also leads to a secondary question - where would I join them in most easily? I assume they connect in somewhere on the massive wire bundle from cabin to engine bay, but what's a good spot to splice in? Just remove protective bundler, find where wires stop crumbling and go with it?
4.a. If I want to just get new plug heads, do those come with the female banana things mounted or would I have to insert the metal and rubber cover too? I think this might be a replacement plug head: https://www.autohausaz.com/pn/9144275
OK I'll give these a go.
1. That is a typical electric motor resistance but doesn't account for seized internals. It's dead Jim. That's a common fail mode.
2. I just disconnect the hoses at the nozzles and run that into a bottle. Then I run the pumps till I see clear fluid.
3. They have all worked for awhile for me.
4. You buy the plug with two leads in it. Pick the proper colors and then you'll have plenty of wire to splice in for the repair.
4a. Yes, when you buy the plug with wires it has the contacts
crimped on and has about a foot of extra wire so you can connect it easily. You can buy butt splices that use a heat gun
to melt the internal solder to the wire and it shrinks the outer casing making a sealed connection. Cut back the black wiring cover till the wiring is good and splice it in there. Buy a piece of wiring loom or good quality tape to cover the wiring when done.
For underhood lines - I just replaced mine with new rather than try to clean out the dried up old ones. Bought a 50' spool of 5/32 vacuum hose for $25, which also works for many of the small vacuum lines under the hood. Recycled the T fittings and spray nozzles.

For the rear washer, if still working - re-running that line would suck. Honestly I'd just disconnect it at the 90* fitting in the back right corner, flush it with washer fluid by running the pump for a while, then reconnect and flush the vertical section out the nozzle. The 90* fitting tends to leak or become disconnected so a replacement and/or judicious use of zip-ties to secure the connection to the barbs may be in order.
The washer pump wires on my '85 were crumbling to bits too. I ended up sliding pieces of heat shrink tubing over each wire and shoving it up into the loom as far as possible. Hopefully, the loom and the added un-shrunk tubing will protect the wires in the loom. I then chopped off the exposed wires close to the loom and spliced in new good wires.

The MTC replacement pumps are fine but they use the weird Volvo bullet connectors. I know that similar pumps, for the same style slide-on mounting posts, exist with more standard connectors, but I don't have the part numbers. There are also universal pump kits that you can screw down nearby.

The 90* fitting in the back of the wagon is a 1-way valve. Mine's currently stuck closed. Whatever you do, don't try to blow it out with 50psi air from the squirter nozzle or you may hear an oh-crap popping noise as the rubber hose in the pillar ruptures.
1. 4 ohm pump and 5MOhm pump both removed, opened, pump mechanism freed and tested, put back in and they work (or at least well enough I'm not replacing for now)
2. front lines were still fairly full, rear needed full prime, no sludge or blockup to be noticed, did need a quick pin poke
3. Irrelevant given neither fully broken
4. What color leads do I technically want? Actual wires crumbled and gross so color readings are like a blind man at midnight. Haynes manual shows front washer as Blue/Yellow for positive, Black for ground, rear washer has Blue/Red for positive, Black for ground. Does that line up with what other people see (I know it doesn't functionally matter, but if I'm going with https://www.prancingmoose.com/blackvinyl.html#2polewithpigtails and customize, I might as well match my shirt to my shoes). I'll take a look at cutting off the covering later on and that'll confirm my color guesses.

Separately, rear sprayer has a pretty wide nozzle that really needed to point down to the glass to spray properly - ended up using a right angle pick since a pin was too small and my smallest allen key was too large.

Separately separately, the ground screw strap on my washer motor hates grounding well (screw on lower left mount that connects the strap from the worm gear backing plate). Should I bother trying to clean threads and getting a good connection there or should I just make a new ground strap that goes elsewhere? I've already wire brushed the screw once.

So basically everything works right now and I electrical taped the bare wire up to the loom spot. Really with there was a specific head and bullet spec to search for rather than going by trust, but this is the automotive world, not mcmaster carr. At a later point (burning wire smell time) I'll likely look at spending money for proper connector replacement.

Might go with bobxyz's method of repair - the stranded wire looks to be in good condition and the connectors work, they just look gross.
BTW if you do purchase new pump motors. The rear pump motor with the black coloring to mark it as the rear is NLA. You just buy two front pumps and color the top of one black with a sharpie if you want to mark it as the rear pump.
4. What color leads do I technically want? Actual wires crumbled and gross so color readings are like a blind man at midnight. Haynes manual shows front washer as Blue/Yellow for positive, Black for ground, rear washer has Blue/Red for positive, Black for ground. Does that line up with what other people see ...

I think so. Go to https://ozvolvo.org/archive/, and if you search for 1984, which should be close to 1983, you can find a wiring greenbook. Pgs 57,61 have a drawing of the pumps and wires.
Visited the junkyard. $5 later and I have two connectors - one from a 760 244's one front pump (pump is a different style), and one from a S60's washer fluid level sensor.

Might splice them in this weekend, we'll see.

Update: Spliced in the connectors (cut, solder, wrap in tape) and added longer shielding in hopes of less decay. didn't go with those cool butt connectors because I'd have to hunt them down and get a heat gun, whereas I have a soldering iron and electrical tape already - also, it's just the washer sprayers.
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