XJS wiper delay module/relay?

My 1983 Jaguar XJS has a delay setting on the stalk. The motor works but it won’t park. I have checked the park switch in the motor housing and it is good. The wiring diagrams talks of a delay switch somewhere in the car. I can’t find it. I have unplugged a few relays while the wiper motor was running but can’t find one that controls the delay or the parking motion. When I turn the stalk off, the wipers stop. If I push the button on the park switch that is mounted on the wiper motor, it keeps running. Something somewhere is not telling the motor that it needs to run the cycle when I turn the stalk switch off. It just stops when I turn the stalk switch off, and the wiper blades can be anywhere!

It is number 2 on this diagram. A delay unit. If I find it and replace it then my wipers will be fixed. One less thing to deal with!

Thanks

Russ

Russ,

I believe it’s above the passenger footwell, accessed by removal of the dash under-scuttle.

Thanks. I did find it and found that it was working. I just didn’t wait for the delay. So it works great. It parks after each stroke of the wipers. Now I need to find out why under the normal low and high speed settings that it won’t park when shut off. Maybe the stalk. The switch is being pushed in the motor but some how the power isn’t kept on when I turn the stalk off so it finishes to the park position.

Another mystery to solve I guess.

Thanks for the help with the delay switch.

Russ

“Maybe the stalk. The switch is being pushed in the motor but some how the power isn’t kept on when I turn the stalk off so it finishes to the park position.”

Probably is the stalk switch, as they are prone to failure and parking current does flow through the switch.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

Ed,

Thanks. I will do some wiring voltage checks tomorrow. I think I read something on the Jag-lovers page about that. I will have to search again.

Russ

Russ,

Here’s what I would suggest.

Make several copies of the schematic and get a hi-lighter pen. For each position of the stalk switch, hi-light the circuit from the ign +12v (LG) to motor ground.

Let’s do it for Slow first. Current goes to SW-1 (switch pin 1), SW-5, M-5 (motor pin 5), M-1, SW-7, SW-2, ground. Motor runs in the normal operational direction.

Strangely, the Off position is more complicated, since there are really two states: when the Park microswitch is in position Z (parked) and when it is in position Y. When first switch to Off chances are high that the motor is not in the parked position so the microswitch is in the Y position. The circuit is then SW-1, M-1, M-5, SW-5, SW-6, R31b2 (relay pin 31b2), R31b1, M-2, M-4, ground. Note that the current is now going through the motor in the opposite direction, so the motor runs in reverse. Eventually the motor will reach the Park position and the microswitch changes to Z, thus breaking the ground path and stopping the motor.

So, failure to park can be caused by either the stalk switch or the relay. I believe we have more reports of switch failures than relay failures. So, I recommend you test the switch.

To test the switch, disconnect its harness and do some continuity tests. In the Off position SW-5 and SQ-6 should be shorted, and likewise for SW-1 and SW-7. If it fails these tests, replace the switch. Otherwise, replace the relay.

Note that I’ve never worked with your particular system. What I know on the matter is from spending the last several months retrofitting a ’89-’92 XJ-S Electrolux wiper system to my ’76. In the process, I’ve done a lot of circuit tracing and testing like this. BTW, I had three bad switches. Two were used eBay purchases, and one was brand new. Fortunately, the problem with the new one was simply that the single-wipe didn’t work. I am currently using it anyway since I can do without that feature.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

The micro switch is fine. And I don’t think there is a relay in the system for normal slow and fast wiping. I do think though that power isn’t coming from the stalk to keep the motor energized long enough for the micro switch to take action, I will follow your advice and check out the wires you suggested. It should be a relatively easy job to follow.

Thanks

Russ,

“. And I don’t think there is a relay in the system for normal slow and fast wiping.”

Correct. The circuit doesn’t go through the relay in these modes.

“I do think though that power isn’t coming from the stalk to keep the motor energized long enough for the micro switch to take action”

I don’t look at it as a question of time for the microswitch to take action. It’s an either/or situation. Either the correct contacts are being made in the stalk switch and the relay, or one of them isn’t.

BTW, way the Intermittent mode also depends on the park functionality. At the beginning of each interval the motor is turned on by a very brief pulse from the relay… it is turned on then off almost immediately. The run/park functionality then takes over, keeping it running until the Park position is reached. If it doesn’t park, the intermittent mode won’t work either.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

I see what you mean. It does park in the intermittent mode, so obviously that part of the electrical system is keeping the motor running until it hits the micro switch. So it must be in the stalk that when switched off, it isn’t keeping current to the motor. So even in off mode there is power standing by that would keep the motor turning if it weren’t for the micro switch. I still haven’t done what you suggested in the earlier posting because of the timing of my car and the holidays. I will this weekend though.

At least the stalk is still available if needed. Thanks for your help Ed. It is getting me closer to getting it back on the road.

Russ

So it must be in the stalk
that when switched off, it isn’t keeping current to the motor.

I haven’t followed this too closely, but there is a known issue with the stalk
switch in that the contact board that the sweeper moves against gets
distorted under years of stress and fails to make reliable contact. IIRC, the
resulting problem usually manifests itself as a failure to park, sometimes
fixed by holding the stalk up gently or some such.

Buying a new stalk switch may or may not solve the problem. Even a new
one is likely to have been sitting on a shelf for decades and may have the
same problem. A more positive fix is to actually modify the switch, providing
additional reinforcement behind that contact board to prevent it from
distorting. When I fixed mine, it involved adding a tiny piece of 1/2"
aluminum angle held in place with two screws. I seem to recall having to
grind away some metal on the housing itself to get the aluminum angle to sit
where I needed it to sit. I was VERY happy with the result, as my stalk
switch worked far better and with more authority than it ever had.

– Kirbert

I will be trying what it is that you did to correct the wiper stalk problem. I was reading the very informative “Help for the Jaguar XJ-S Owner” and read of several attempts to fix this. Yours seems the most viable way. It also talks of putting relays in the system to get 12 volts to both high and low speeds so the stalk doesn’t have to have that kind of current running through it.

Saving $125 is a lot better if it can be fixed. I do appreciate the advice.

Russ

Russ,

I took one apart and can tell you there will be a challenge to get it back together. The pot-metal body has tiny posts that poke through holes in the cover plate and then get peened over. To get it apart you have to file or drill them out. However, when you want to reassemble, good luck! I’d be glad to send you this one to practice on. Or, I could send you some photos. It’s from a later model XJ-S so won’t be exactly the same as yours.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

Well, I did push on the end of the stalk while turning the wipers off and it did work. It didn’t take much pressure either. I can see then when I read about some thinking about fixing them that the easier decision was to just put up with it.

I would appreciate both if you don’t mind. Either way though I guess I will be taking mine apart. Photos would be great first. I finally put the wiper motor and grill back on the car so hopefully I can fix the switch and have that part sorted out.

Not sure if you want to send the photos here or my email but either is ok. rnoswal@suddenlink.net the first letters are an r and n, not an m.

Thanks

Russ

Yes, relays are highly recommended, they will literally transform your wiper system.
Aristides

I read that in the Help for the Jaguar XJ-s owner by Kirby Palm. I thought I would do that before I had to put together the dash and glove box area. They talk about it but I am better with actual pictures and with actual part numbers for the relays. I have used relays that come in a headlight upgrade system but not sure what to ask for at the parts store. At some point there was an upgrade to the fuse box in splitting a fuse that was almost always over used. So that mod was done but the windshield relay is something I would like to do also.

Do you know of anyone who has done this with parts and pictures in this or another forum?

Thanks

Riss

Russ,

As I mentioned, I’ve just finished my retrofit of an ’89 Electrolux wiper system to my ’76. I completely rewired the whole thing, including a new power relay so the current to the wipers is not drawn through the ignition protection relay. However, the current to the wipers DOES go through the stalk switch. However, I do not think it’s practical to avoid going through the stalk switch. The reason is the switch has to provide +12v several (3) different connections at the delay relay and motor. Consequently, meaning you would have relays all over the place! Moreover, the stalk switch, if it works at all, can easily carry the needed current.

OTOH, there is some argument for not drawing wiper current through the ignition protection relay, since that relay carries all the current for everything else that needs current when the ignition is on. If you do want to do put in a new power for that, I can tell you exactly how to do it.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

However, I do not think
it´s practical to avoid going through the stalk switch. The reason
is the switch has to provide +12v several (3) different connections
at the delay relay and motor. Consequently, meaning you would have
relays all over the place! Moreover, the stalk switch, if it works at
all, can easily carry the needed current.

The problem isn’t so much the stalk switch as the wiring. The power having
to go back and forth between the wiper motor and the stalk switch absorbs
too much of the voltage, leaving the wiper motor to run on severely reduced
voltage. It shows in wipers that “move as though they are dragging
themselves into the grave.” The point of adding relays to the system is to get
full voltage to the motor so it runs like it should. It does involve several
relays, to be sure, but relays are dirt cheap, especially if you get them from a
junkyard.

OTOH, there is some argument for not drawing wiper current through the
ignition protection relay, since that relay carries all the current
for everything else that needs current when the ignition is on.

The entire point of the ignition protection relay is to handle current to take the
load off the contacts in the ignition switch. So you’re talking about adding an
ignition protection relay protection relay. I suppose that makes sense if the
contacts in the ignition protection relay are overloaded, but I haven’t heard
any reports indicating that they are.

– Kirbert

Are you talking about the wires between the stalk switch and the wiper? I don’t think there’s much resistance in, what, 5-6 feet of 16-18 AWG stranded wire.

I agree that relays are cheap, but places to put 3 of them and provide all the wiring would a nightmare, in my experience.

I remember when this came up years ago so I connected a DVM to one of the wiper motor wires (don’t remember if it was Fast or Slow) with the stalk switch on. I don’t remember the exact voltage, but I do remember it was not below 12v, so I set the matter aside. Nevertheless, since I was doing a complete rewiring for my retrofit anyway I decided to put in a power relay just to be sure the wipers get the highest possible voltage. Basically, it’s a matter of running the ing +12v to pin 86 of a new relay, then relay pin 87 to the stalk switch 1, replacing the original source of ing +12v that comes from the ignition protection relay through fuse 11 (on my car). BTW, the car was fitted with an ignition protection relay from the factory, component 204 on the early XJ-S circuit diagram. So, am not talking about adding one. Also, I would think this relay is intended to provide the ignition (coil, distributor, etc.) with full voltage regardless of periodic current draws from things like the wiper, AC fans, etc. IOW, in my opinion (perhaps wrong) it’s protecting the ignition, not the switch.

Ed Sowell

'76 XJ-S coupe, red

http://www.efsowell.us

I agree with your assessment about the relays. What I read sounded like a reason for the stalk to fail but after reading this and knowing that the one in my car has lasted over 30 years, well I will try to repair mine or live with the problem.

Thank you for the pictures too.

Russ

Russ,
I did put the relays as described in Kirbys book and I can attest that it really made a difference and they are not dragging themselves into the grave any more !
The relays are the very common and very cheap SPDT automotive ones, and can be found everywhere…
The most complicated part is figure out the wiring.
I mounted the relays on the battery support, very convenient as it’s really close.
Also, instead of connecting the wires directly I’ve put a connector plug in between, so it is reversible, and helps for troubleshooting if something goes wrong.
Best,
Aristides