Northwest Nova

Overview

The Chevy II debuted with a newly designed "non-depressed" electric windshield wiper assembly available in three configurations.  The base level (and standard) system was the single speed with no windshield washer.  A step up from that was the uncommon single speed with washer, optional through the 1966 model year.  The top option was the dual speed wipers with windshield washer.  This is the upgrade most often encountered over the base single speed and is relatively common. It became standard in the 1967 model year.  A wiper delay option (the "Pulse" system) appeared in 1975 with the 5th generation Nova and was available through 1979.

Most pieces of the pre-1975 wiper system are now reproduced, with American made replacement switches available for some applications.  Good used parts are common and NOS pieces can often be found on eBay. Switches and some knobs do interchange with other GM cars.  The motors give out more often than the switches and people butcher the wiring, so if you are encountering issues with the system, start there.

 Buyer Beware...

→ Part advertised as wrong year(s), this includes reproductions!
→ Stripped mounting threads either on the switch, nut or knob.
→ Part damaged or mutilated from improper removal – common with the bezels.
→ Switch actuator shaft bent on switches with the washer option.

THE PARTS – WIPER SWITCHES AND RELATED HARDWARE

— Group 10.16 —

GM part name per the catalog in ( ) when applicable.

GM used numerous wiper switch assemblies during the classic Nova's production run.  The switch design varied based on dash configuration, wiper speeds and presence of the windshield washer option.  The switches were not unique to the Chevy II and could be found in other GM vehicles, such as the Corvair and Chevelle.  This makes good used and NOS relatively easy to find, most are also reproduced.  Disassembly and cleaning of the internal electrical connections will often restore functionality to a non-functional switch.

Year(s)	Model	GM Part #	Application Notes
1962—64	ALL	1998729	Single speed w/out washer -- 1993441 supersedes 09-79 [1]
1962—64	ALL	1993541	Single speed w/ washer — Part Reproduced
1962	ALL	1993527	Two speed w/ washer — Not reproduced, use 1993584
1963—64	ALL	1993584	Two speed w/ washer — Part Reproduced
1965	ALL	1993677	Single speed w/out washer
1965—66	ALL	1993680	Single speed w/ washer — Part Reproduced
1965—66	ALL	1993679	Two speed w/ washer — Part Reproduced
1967—68	ALL	1993395	Two speed w/ washer — Part Reproduced
1969—71	ALL	1993464	Two speed w/ washer — Part Reproduced
1972—76	ALL	1994180	Two speed w/ washer — Part Reproduced
1975—76	ALL	356114	"Pulse" (delay) wiper system
1977—79	ALL	1994199	Standard wiper system
1977—79	ALL	461210	"Pulse" (delay) wiper system

1. There is reference in a 1973 GM book to a switch part #1993323 that 1993441 supersedes.  No application is given and we have found no other reference to 1993323.  It could be a misprint or human data entry error, which was common in 1970s parts books.

The wiper switch knob varied quite a bit in the 1962 – 67 period.  Early models with the optional windshield washer had a knob with a cast metal button in the center.  1962 – 64 100 & 300 Series models used a black plastic (Bakelite) knob in place of the chromed diecast piece.  Chevy started standardizing the switch knob around 1966 and by 1967 it was the same across car makes & models.  The pre-'67 knobs interchange here and there with other Chevrolets, with the possible exception of the base model black plastic knobs (they may have been used in trucks & vans).

1969 and later switches were of a completely different design and had an integral knob—a knob that was considered part of the switch assembly.  This knob can be removed and is reproduced on its own, but GM did not give it its own unique part number. The 1975 and later optional "pulse" wiper system did use a non-integral and unique knob that GM gave its own part number.

Year(s)	Model	GM Part #	Application Notes
1962—64	100 & 300 Series	1991014	BLACK PLASTIC – single speed w/out washer
1962—64	100 & 300 Series	1991015	BLACK PLASTIC – single & two speed w/ washer
1962—64	400 Series & Super Sport	3780348	CHROME – single speed w/out washer
1962—64	400 Series & Super Sport	1990992	CHROME – single & two speed w/ washer — Part Reproduced
1965—66	ALL	3859221	Single speed w/out washer
1965—66	ALL	3859222	Single ('65 only) & two speed w/ washer — Part Reproduced
1967—68	ALL	3906147	Two speed w/ washer — Part Reproduced
1975	ALL	356138	With "Pulse" wiper system

All 1st & 2nd generation individual bezels were stamped aluminum, clear anodized (not chrome!) and embossed with the word "WIPER" in black.  The exception being 1965 400 Series and Super Sport models, which utilized chrome plated plastic dash trim. 

The bezels will have a flat edge on the inner mounting circle that properly clocks the bezel onto the switch.  1966 & '67 visually use the same bezel, but the inner mounting flat spot used for clocking vary due to the use of different wiper switches;  hence why GM lists two different part numbers for what seems to be the same bezel. This is an obscure detail most are unaware of and the repop does not take into account. 

1968 and later switches mount into the large plastic instrument cluster bezel from the rear and do not use any form of front metal accent or cover.  The 1975 and later optional "pulse" wiper system is the exception to this.

Year(s)	Model	GM Part #	Application Notes
1962—64	ALL	3791059 [2]	None
1965	100 Series	...	See notes below
1965	400 Series & Super Sport	...	Uses a large chrome plastic piece, not a bezel — Part Reproduced
1966	ALL	3859223 [3]	Mounting flat spot at STUB o'clock — Part Reproduced
1967	ALL	3897350 [3]	Mounting flat spot at STUB o'clock — Part Reproduced
1975	ALL	370145	Pulse wiper switch knob bezel

NOTE:  1965 100 Series models may have used two different style dash bezels.  Early parts books indicate use of the 1962 - 64 bezels, later books show the 1966 bezel.  Our experience is '65 100 Series using the '66 bezel, however I have seen a picture of an original looking car using the earlier style.  GM very well could have used both and there is a manufacturing bulletin somewhere out there notifying of the change.

2. Correct reproductions are not currently available.  A version without the "WIPER" embossment is on the market, but not prevalent.

3. Available reproduction as part of a dash bezel kit.

The retaining nuts or "ferrules" are the same as other Chevys of the period.  You will see some variation in appearance between nuts of the same application (and part number).  Likely an indicator of multiple manufacturers or different production runs (or both).  Threads do not appear to have varied, but size did. Some are bigger – wider or taller or both – than others, being employed with larger dash bezels.  With the Chevy II the only one to be wary of is the '65 ferrule, which is larger and does not fit properly with the other year bezels. 

Suitable (not exact) reproductions are available. The repop nuts encountered on the market are often sold as fitting all years, which they usually will.  Good used can be surprisingly difficult to locate at times. It is an often overlooked and lost (or tossed) part.

NOTE: 1969 and later switches were of a completely different design and screwed to the dash bezel from the rear.

Year(s)	Model	GM Part #	Application Notes
1962—67	ALL	3820531 [4]	Except '65 400 Series & Super Sport — Part Reproduced
1965	400 Series & Super Sport	3838353	With chrome plastic dash trim — Part Reproduced
1968	ALL	3916709	Control Switch Nut. Discontinued 12-1981.

4. In later parts books 3820531 is listed for all 1962—67 Chevy IIs.