SS details #3: Marelli wiper motor

I mentioned I was digging through my parts organizing them, well I came across this Giulietta SS Marelli wiper motor at the same time as the heater vents. It has been patiently waiting for me to clean it up and test it. It looked pretty good and clean on the outside but you know what they say about appearances so I decided to have a quick peek inside of it. I’ve never gotten into an electric motor besides a Bosch 105 starter that I took apart after it burned up from a solenoid stuck on. Imagining this wiper motor is only used on Giulietta SS’s and Ferrari 250 Lusso’s I went slow and was gentle with the tools.

wiper motor 1This is the before shot. I had been messing around with an old Weber so I had some fresh carb cleaner handy to clean the goo off the outside.

marelli wiper motor ssThe makers mark Magnetti and Marelli, made in Italy. I’m glad that rusty bolt and washers is present so I know what the original hardware looked like.

marelli wiper motor connectorHere’s where the wiring hooks up to it. Seems like a lot of wires, maybe it has two speeds. Note the lacquered cloth wound wires.

disassembly of marelli wiper motorI unscrewed the two long machine screws and pulled the end off using the little cut out provided that can just barely be seen at the right on the edge of the body.

Marelli wiper motor gutsSurprise! Wow, it’s almost perfect in here. The cloth wrapping and copper wires of the commutators is like new and the inside of the casing is spotless.

marelli wiper motor brushesOne of the brushes goes to ground, the other to power. I guess I should read up on these kinds of motors with brushes. I think the armature is basically a rotating electromagnet and as it turns the brushes excite different parts of it.

marelli ss wiper motor armatureHere’s the armature and one of the screws holding the lot together. That armature looks NOS to me, I guess the car this came off of never got driven in the rain. I do know the angular placement of the layers is to spread out the transients of the push from each as it goes through the fields. I think the way it works is if there are 30 layers and they are in 12 groups 30 degrees apart one layers transient starts every degree spreading the torque out very evenly. Any EE’s care to chime in? I put a light dab of grease on the short end of this before reassembly. Should have put it in the bushing the end goes into, would have saved me worrying about getting it on the brushes.

marelli wiper motor brush wear SSThis brush has almost no wear. Cool, I don’t have to try and track a set of brushes down.

cleaned wiper motor assembly ss marelliThe intrepid explorer closes up the patient and hopes it will function correctly after the operation. Very nice unit.

I am happy with this wiper motor turning out to be so clean. If it works as good as it looks I’m in business. I’ll figure out what the multiple electrical connectors are for and test it before I install it in the car. This motor looks a lot like the Marelli motors that come up as fitting FIAT’s if you do an eBay search. I bet one of those could be retrofitted to work. It’s nice to be back on the SS even if only tackling little jobs like this. Where am I, 900 hours to go?


2 thoughts on “SS details #3: Marelli wiper motor

  1. HI



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