My thanks to Ralph Gosnell, he let me borrow an original factory wiper interval wiper relay harness. I have since done some initial research and it looks like I could make these available, with a new relay.

I could make the harness available in the $40.-50. range, and the relay is available at cost for about $65.

The harness would come with detailed pictorial installation instructions and the wires would be correctly color coded. It would take careful scrutiny to see the difference from my harness and an authentic factory harness.

Please respond to this post if you would be interested in getting one of these harnesses. I suspect I would just provide the harness and tell you how/where to obtain the relay. Your response is not a committment to buy, I am just gauging interest to see if I should develop this idea further and order parts.

Thanks! Jeff

I would buy one. And I know my dad wants to do this to.

Apparently I'm out of the loop. How does the delay work?

Yup, I'm in! I think I already have the relay from years ago before I knew I needed to create a place to put it.

Jeff, I'd like to wire in a relay, but in my '70 with the switch on the dash. Is it doable?

This sounds like a very practical idea; I'd also like to have one.

I think I have a socket for the relay - just no relay? I have a '73. Is this possible?

Where do I get a relay from?

Oh - and what are common causes of the wipers not retruning to base when they are switched off?

Fiid.

Jeff, I absolutely want one. Hell, I'll pay you the money just to make me one now. We could call it a demo test run.Since i live in CO and am getting snowed on every friggin day lately, it would be a good test year!

Sounds good to me.

Geoff

interested? hell yes. let the r&d begin.

kevin

The 74 model year came with some of the harness in the car. The relay needs a socket and short harness to connect to the body harness. The relay / socket bolts to the drivers side cowl support. You also need to have a suitable wiper lever with the extra contact, and I think the column cover needs to be trimmed to allow the lever to be used. To install in an earlier car would need a fair bit of extra work.

DaveP

Jeff, Count me in. I always wanted the interval feature. Provide good instructions, though. I am not the most electrically-inclined, but I can usually follow a wiring diagram.

Mike

Martin,

Your 74 should have the wires in the body harness. I had to unravel part if the wrapping to find the ends, but they were there. Just around the brake fluid reservoir.

DaveP

If this is like what my '95 VW Jetta implements then I recommend it! Not sure if I will commit to buying one due to the extra column work involved for a '73 and I have bigger problems to address (rust).

yepp, the later cars (i think '74 and onward) have the wires to hook this up.
actually, all you need to make it work on a older car is to run the brown/black wire somewhere to the inside of the car and add a switch.
all the other wires connect to the wiper motor which are the same for early and late cars.

btw. this is NOT a wiper delay, this is a "intermittend" switch.

what it does is:
if you move the wiper lever towards yourself to activate the windshield washer the wipers will come on and run 4 or 5 turns, then shut off.
that's all!

if you have a electric pump, you can extend the brown/black wire to the pump to also operate the pump when moving the lever. (same result as above).

earlier cars don't have the needed switch on the wiper lever at the column (really early cars don't even have the lever, they have a knob on the dashboard).
the easy way to test if you have the needed switch in your column is to find the brown/black wire that exists from your steering column into the wire-harness.
there is a detailed reference to this complete "intermittend" wireing in the Haynes Book somewhere in the electrical pages.

some of this is shown here:
Wiper Relay Instructions

hope this helps,
Andy

No, if you move the switch down a notch from OFF, the wipers run at a pre-set interval of every 2 seconds or so (I have not measured the time).

mine doesn't!

but it DOES move 4 or 5 times every time i use the windshield washer.

now i'm confused,
Andy

I think the wiper relay does both features.

Did you break out the plastic tab so you can move the wiper switch down? I don't remember on the washer, as I do not run a washer (I hate the excess washer fluid running all over the place).

I have a '74, got the parts off a '74 2.0 and found the original wiper switch did not have the extra contact/wire terminal for the feature. Checked the switch from the 2.0 and it was there! Same P/N. The brown/whatever wire was in the harness.

i actually tested it for that said function before i assembled the unit.
however, the unit i have did not have an extra position below the OFF.
i could not move the lever down and i did not get any movement on the wipers.

how can there be 2 completely different "modes" if there's only ONE control wire from the lever to the relay ???
if you take the assembly off the steering column, you can actually see the switch closing on the opposit site.

still confused,
Andy

OK, well I'm confused to. I never looked at the diagram or the wiring, I can only tell you what my (1974) car does. I know it does the delay, I just used it today.

Maybe there are two versions of switch/relay?

It may be that there are two different relays, one for each function. Please check the relay part numbers.

DaveP

I'll see if I can get the number off mine tonight, and I'll check the washer functionality.

I have 111 955 531 w/a 11/71 build date from the donor '74. It's the S1 contact thats missing from my original '74 non appearance group car.

I would like to know what the internal wiring of this relay looks like too - I am interested in building (and selling) a small circuit that replaces it and provides variable speed for intermittent wipe.

And why don't my wipers return when I turn them off?

Fiid.

Not sure if this is the same or what since there seems to be some confusion but I'll add it anyway. Here is how to add an intermittant wiper relay to the VW Type III (air-cooled stationwagons). The wiring colors/routing should be consistant between VW and Porsche so route wires accordingly. For experienced electrical users only. Batteries not included. Don't ask me for help cuz I've never done this to any car. Don't run with live grenades. Perform at your own risk.

At the bottom:
http://www.icbm.org/erkson/ttt/windshield_...tem.html#custom

I could definately go with intermittant wipers ... bring the harness on.

OK, I just got in from the garage.

1974 2.0 has relay part #111 955 531.

When I pull the lever for the washer, the wipers traverse twice (wipe/wash function).

When I push the lever down, the wipers traverse every 5 seconds (delay function).

I also have a relay from a 1976 and that is also #111 955 531.

now that I think of it, my 74 has the same functionality as James'

ok, so the difference is in the relay AND the switch at the column.
(mine doesn't have the DOWN option) ...

interesting
Andy

I'm thinking of going even simpler than that with a dial from an SC.

Thanks for the great responses so far...I will hope to shed a little more light on what I have found...and maybe more confusion.

The Factory Manual calls it a 'wiper interval relay-(optional)', on both the 1972 and 1973 model year schematics. In 1974 they issued a separate 'Additional wiper interval' schematic, dated 1973. There is no similar diagram for the 75 model years and the factory manual does not cover the 1976 model year. I havent studied the schemantics in any detail to see if there are other differences, which I need to do.

I dont know how the wiper interval relay works internally Fiid...but why reinvent the wheel? Its only a paltry $65 for the real deal...

The factory manual has a diagram and instructions for the conversion, dated 1973, at page 4.4-6/1. To me that means the 74 cars would be capable of a direct swap in retrofit. It maybe possible to retrofit a new switch and wiring into an early car, but I dunno...

The relay can be had from PP or apparently anyone with access to Bosch. PN 111 955 531 is apparently the originally specified relay. It has been superceded by PN 477 955 531 according to Darren at PP. He quoted me a price of ~$57. +tax/shipping. The relay has some microelectronics in it...capacitors and a chip I think, not just a typical on-off electromagnet type relay. If I do these harnesses, I'll just do the harness and let you get your own relay....I have no interest in inventorying something you can easily get on your own.

The wiper delay/relay is not an appearacnce group item, it was simply an option...like the rear window defroster.

The harness I have seen only has four wires - Brown, Green/white, Red and Blue/Black. Andy described his install as having 5 wires, which corresponds to the 1974 'Additional wiper interval' schematic, in fact it corresponds to each of the 72-74 schematics. The additional brown/black wire comes out of the main body wiring harness and is attached to the S pole of the relay, which goes to the switch.

In either case the wiper lever arm/switch and/or the steering column housing needs to be modified (a tab removed) so that the multi-positions can be achieved.

Jeff

Edited Feb 26, 5:20 am

That's good to know. I thought the factory relay was NLA.


Here's an idea:

Is there any reason why the original relay needs to be used? It seems like designing a harness that uses, for example, a $5-10 relay from the FLAPS would be a great solution.

The original relay does appear to be NLA Anthony...thats why there is a substitute relay with a superseded PN.



Which is why its not a $5 relay. It looks like a relay but its not a relay at all....its a circuit stuffed into a realy-like box.

Its the same as a 75 and later Bug so go to a VW parts store to find one.

Right, but why does that part have to be used? Is there a technical reason? FWIW, JC Whitney sells a intermittant wiper kit for $16.

As I have unequaled access to factory stuff...I work at a dealer, I can tell you all what I've done for my '73 1.7. The factory harness is STILL available, part number 914-612-143-10. According to factory info, any car built after 02/01/72 (basically late '72 or later) should have the wiring you tap into already in the car. I then got a relay, which was originally part number 111-955-531. This has been superceded to a 924 part number...starts with 477-. I also got the wiper column switch out of a '77 924..getting hard to find from the factory, but I think it's available aftermarket. This switch already has the plug out for the interm. postion. I found the wiring under the cowl to tie into, and also the other end, under the column. I remember changing the white plastic wire holder from my switch to the 924 one so it would fit in my column. My car operates as the others have said, and it's a whole new world on the frosty new england mornings.

Thanks for the heads up on this Partsman. I have verified it is available still...this thread is dead. If you want one...get it from your friendly Porsche dealer... Glad to know the real ones are still available.

Bollocks. There was a 924 at Pick-n-Pull when I was down there the other day. I didn't even know to look for an intermittent wipe relay otherwise I would have snagged it.