Variable (delay) sweep wiper mod (1HM 955 531A)

[rachaeljf]

The VW 99 relay is effectively a changeover relay with some electronics on top, more about this below. There appears to be two types, one with variable interval and the other with fixed interval. The variable type has an arrow on the electronics on the wiring diagram printed on its side (with thanks to the Sterling Kit Car forum):

Here is another circuit diagram:

Regarding the above diagram: Interestingly, this diagram shows a connection between the motor low speed and the switch and the 53M wire tees in. Studying the Fiat diagram, it does seem that this should be ok as when the stalk is in the intermittent position, all the various grey wires are floating and only the intermittent relay can add any juice. I was worried there would be some unwanted interconnection that would override the intermittent relay, but it seems ok and that was a red herring.

I'm not sure the direct connection of the ground to the park switch is correct, as it appears that every time the motor passes the park position the motor supply is momentarily shorted to ground, given that 53M and 53S are internally connected when the 99 relay is inactive. Fiat takes care of that by having the ground wire (blue/white) floating whenever the motor is running and only grounded when the stalk is in the off position. Also I would never have the 12V supply to the park switch permanent as that's a trapped finger or poked eye waiting to happen.

Regarding the 99 relay and its operation: If no power is applied to any pins, pins 53S (=87a) and 53M (=30) are internally connected same as a changeover relay. When the relay's brain commands a sweep, it fires the relay coil to disconnect 53S from 53M and instead connect 15 (=87) to 53M. Applying 12V to terminal T (=86) also activates the relay and its brain keeps it activated for three wipes after you remove the 12V.

Can you confirm that with the 99 relay in your hand, pins 53M and 53S are connected? Also, did operating the washer give you three sweeps of the wipers?

 

[Dr.Jeff]

I know there was at least two versions of the VW relay, but off hand I don't recall the part numbers or exact programming instructions. I have it all documented somewhere, but what everyone has said in the last couple of posts sounds like what I remember. Sorry I don't have more to offer at the moment, but Rachael has it well covered.

 

[lookforjoe]

Can you confirm that with the 99 relay in your hand, pins 53M and 53S are connected? Also, did operating the washer give you three sweeps of the wipers?

Thanks Rachel.

Mine is as pictured.

Yes, 53m & 53s are connected when coil is not powered. I also checked it with an ohmmeter. Operating the washer gave me 3 sweeps.

The only aspect that doesn't work is the delay. I do need to recheck the sequence I used, as I said in last post. I'll confirm tomorrow. I don't believe It's the wiring, as the Volvo relay performs all functions as expected (besides no program)

my wiring (not showing dual relays to offload switch)

 

[lookforjoe]

Definitely no delay function at all with the 99 relay I have. Every other aspect works. I'll have to get another one

 

[rachaeljf]

Something is amiss with your wiring. There is a grey wire that comes out of one ganged switch in the stalk switch and loops back into the another of the ganged switches, maybe you cut into that one. In fact, looking at your hand drawn diagram, there should be a local interconnection between the two grey wires coming from your two ganged switches.

That's bloody annoying if the relay is dead

 

[lookforjoe]

Something is amiss with your wiring. There is a grey wire that comes out of one ganged switch in the stalk switch and loops back into the another of the ganged switches, maybe you cut into that one. In fact, looking at your hand drawn diagram, there should be a local interconnection between the two grey wires coming from your two ganged switches.

That's bloody annoying if the relay is dead

I did cut that loop - it joined the grey 53s going to the relay to grey 53m to the motor. You did say the two needed to be isolated

 

[rachaeljf]

Ah, it needs to connect *before* it gets to the 53S terminal! I originally thought only one grey wire should run from the 53M terminal to the motor. But as I said, I don't think it does any harm to have it connected downstream. Have you got my complete pdf diagram with the 5 gang column switches shown? I have shown the local interconnection but I don't know how far the loop goes into the loom.

 

[lookforjoe]

Ah, it needs to connect *before* it gets to the 53S terminal! I originally thought only one grey wire should run from the 53M terminal to the motor. But as I said, I don't think it does any harm to have it connected downstream. Have you got my complete pdf diagram with the 5 gang column switches shown? I have shown the local interconnection but I don't know how far the loop goes into the loom.

Hello Rachel - this one? - In the diagram it looks like 53s is the one that loops to the switch terminals, not 53m - I tried reversing those two so that 53s went to the two switch positions & that didn't work either, so I need to put back the loop from 53s to 53m at the switch connector, you think?

the factory wiring for 53m / 53s was as per my crude sketch, with the loop at the switch gang plug (loop itself was about 6" or so back into the harness:

 

[rachaeljf]

Going back to your large hand drawn diagram, if you disconnect the grey wire running from stalk terminal [10] to the motor INT, run it instead from terminal [10] across to the unlabelled grey wire terminal between [2] and [8] and splice the grey wires there, that would replicate my diagram.

 

[lookforjoe]

Going back to your large hand drawn diagram, if you disconnect the grey wire running from stalk terminal [10] to the motor INT, run it instead from terminal [10] across to the unlabelled grey wire terminal between [2] and [8] and splice the grey wires there, that would replicate my diagram.

OK - I'll try that. The only thing is, without the grey wires going from 53m to the switch, the wipers don't park. I tried disconnecting the two wires from [10] at the switch (diagrams only show one wire at that point, but in fact there are two, so actually 3 grey wires at the switch) altogether, and the wipers don't park.

I did try reversing 53s & 53m at the switch plug, that didn't work.

I'll try adding a bridge that connects all three grays at the switch connector.

EDIT - [10] on the right is [10] on the left relay part of the diagram, sorry I didn't clarify that it in the diagram - so [10] is already going to [int] on the motor. I'll add the bridge

 

[rachaeljf]

If you look at my diagram, you will see there are indeed four grey wires joining at the connector. According to the Haynes BoL diagram, there are two on each side of the connector, but you may well have three on one side and one on the other. Simply reversing the wires at the 53M and 53S terminals would not work.

 

[lookforjoe]

If you look at my diagram, you will see there are indeed four grey wires joining at the connector. According to the Haynes BoL diagram, there are two on each side of the connector, but you may well have three on one side and one on the other. Simply reversing the wires at the 53M and 53S terminals would not work.

Hello Rachel

I'll just put it back as it was - with a loop at the switch connector between 53s & 53m (with only harness side of 53M connected to motor) & see if that does it

 

[Dr.Jeff]

Regarding the relays, there are a number of aftermarket makers of this part. Some better quality than others. But looking back at post #34, it appears you have a actual "VW" part. Therefore the quality should be fine, regardless of where it was produced (looks like Mexico). It's always possible for the part to be bad, and if it was from certain other makers I'd suspect that. But I doubt it in this case.

I imagine you already tried a different approach for the programming sequence? Seems you said you might of had that wrong before.

 

[lookforjoe]

Temporaily connected the two wires previously going to 53M (from the switch) to the switch wire going to 53s on the relay. Delay function now works as intended - I can program time of delay as wanted. Makes sense, as the relay was not staying activated - now, with the internal supply from 15 to 53m, the relay stays powered whilst the delay feature is set.

Thanks for bearing with me Rachel!

all tidied up, made a "Y" from the 53s to the switch connector, and connected the two grey wire shown above to the second wire.

 

[rachaeljf]

That's excellent, congratulations! I'm kind of relieved too I must say!

 

[Mark]

I’ve been wanting to do this. Do you have a diagram of the final wiring conduct?

Temporaily connected the two wires previously going to 53M (from the switch) to the switch wire going to 53s on the relay. Delay function now works as intended - I can program time of delay as wanted. Makes sense, as the relay was not staying activated - now, with the internal supply from 15 to 53m, the relay stays powered whilst the delay feature is set.

Thanks for bearing with me Rachel!

View attachment 41152

all tidied up, made a "Y" from the 53s to the switch connector, and connected the two grey wire shown above to the second wire.

View attachment 41154

 

[lookforjoe]

I’ve been wanting to do this. Do you have a diagram of the final wiring conduct?

Will you be repurposing some of the stock wiring or adding new wires to the new relay? I can do a drawing with the steps (Rachel outlined) listed, if mine are easier for you to read than Rachels...

 

[Mark]

Repurposing as much as possible.
I wasn’t sure where the relay gets placed in the circuit. Does it go at the column switch or in place of the stock delay?

Will you be repurposing some of the stock wiring or adding new wires to the new relay? I can do a drawing with the steps (Rachel outlined) listed, if mine are easier for you to read than Rachels...

 

[lookforjoe]

Repurposing as much as possible.
I wasn’t sure where the relay gets placed in the circuit. Does it go at the column switch or in place of the stock delay?

It will go where the stock relay went. you will need to buy a relay socket that has a mount ear so you can bolt it in the stock location - I'm assuming yours is similar to mine here. If yours does not have the ATC fusebox like mine, I do not know where the stock relay was mounted.

 

[Mark]

It will go where the stock relay went. you will need to buy a relay socket that has a mount ear so you can bolt it in the stock location - I'm assuming yours is similar to mine here. If yours does not have the ATC fusebox like mine, I do not know where the stock relay was mounted.

I will be installing this on my '85, so it should be the same as your car. Reading through the posts, it sounds like wires at the column switch will be spliced and ran to the relay. Here is the Bertone wiring diagram: