Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) wiper delay

i have a problem with the intermittent wiper which hasn't worked for some time.
all other functions on the wiper stalk work OK.
i have changed the relay but it made no difference.
i want to check the stalk wiring.
the question is what are the steps to get at the wiring to check it.
i guess the steering wheel has to come off and then the indicator/wiper switch assembly.
any advice on how to do this and when dismantled am i likely to see the terminals?
thanks in advance.

No need to remove the wheel.
Just remove the screws on the cowl.
Remove the cowl and you have access

The wiper stalk comes off quite easily. You can then unplug the wires to the loom.
Can’t find the Google link at the moment showing how to place a thin screw driver to lift the stalk assembly over the little pin. But it is somewhere. On the discovery forum iirc. Just caution when removing the small tail lead as the tab it sits on is brittle.
I recently finally found the cause of my washer problems. Chafe on wires into loom. You may have something similar.

Paul although you have changed the 6 pin wiper delay relay please note that MMC appear to use the standard 5 pin relay base connector with a sixth connection added for the narrower "I" pin. This is the one that accepts the intermittent trigger so worth checking this connection is good as a replaced relay could still leave no connection here and it's a known issue! If it helps it's the pin with orange/green wire connecting to wiper stalk resistance array via a flying lead at stalk. It may save you checking at the wiper stalk. Please also read this article I wrote on wipers employed on later Classic Mogs:

Have been unable to find any in depth explanation of the functioning on the wiper control system used on recent Morgan Classics with wash and delayed wipe, or indeed of similar on any other marque. Below is my attempt at explaining the system based on research into chassis loom, delay relay and wiper stalk. Models from around 1997 and on to end of Classic production, appear to employ both the same wiper stalk and delay relay so should function similarly.

The Lucas 14W two speed wiper motor has the usual self parking mechanism employing an integral changeover switch operated by a cam on the drive wheel. This allows continued current to motor after wipers are turned off until the cam, coinciding with the wiper park position, throws the switch to ground the normally live side of the motor. This puts a short on the motor windings and with help from the motors back emf brakes it, so preventing overrun of park position. The motor has three brushes oriented to allow slow and fast wipe speeds. Wipers are controlled by the right hand Lucas steering stalk. Note it functions standalone with no connection whatsoever to CANBUS, ECU or BCU.

A downward pull on the stalk against spring detent engages slow wipe, allowing a single wipe with timely release. Pulling stalk forwards against spring operates screen washer pump whilst simultaneously applying +12 volts to a timed hold trigger on an integrated circuit (IC) within a dedicated six pin plug-in wash/delay relay (pin 53c). The IC then conducts on the ground side of the relay coil (pin 31). As the other side of coil is permanently connected to +12 volts (pin 15) whilst ignition on, this allows it to energise and switch the changeover contacts (pin 53e) to allow current to slow speed connection on wiper motor. The coil remains energised by the IC long enough to allow three or four (dependant on wiper speed) further slow wipes after stalk is released.

First twist position on end of stalk engages delayed wipers commencing with a single slow wipe. Each of five delay periods are selected by an inner knurled twist selector, longer downwards. Each position switches a resistance array within the stalk in the range zero to 7.5k ohms (max delay) with +12 volts being fed through the resulting resistance via a flying lead connector to a second delay trigger on the relay IC (pin I for interval). After delay the coil is energised briefly to allow another single wipe before repeating. Further twists on end of stalk engage slow then fast continuous wipes independant of delay relay.

Note the self parking mechanism is electrically routed through the relay so only takes over when intermittent or off is selected on stalk end switch and relay coil is de-energised by IC via normally closed relay contact (pin 31b) to wiper motor park switch. This of course happens seamlessly such that the briefest of wiper commands will produce a full wipe and will always leave wipers parked when turned off.

The wipers will always stop unparked if the ignition is turned off whilst they are functioning, however if this happens with it on, especially intermittently, suspect the parking switch which is an easy fix as it simply clips on with replacement readily available. Note also the wiper delay relays sixth pin labelled "I" is narrower than the others. It appears MMC use a modified 5 pin plug-in base which may not provide an adequate captive connection for same so worth checking if you have a wiper delay issue. Hopefully above info will smooth fault finding.

Replacement part numbers:
Motor: Lucas 14W 12v 2 speed PARK->
Stalk: Lucas STC4016 or SQB161
Delay relay: Wehrle 60 201 002

A simplified version of the system is shown on this wiring diagram although wiper relay pinouts are slightly different and the delay is fixed. It does help illustrate my text above though.

Yep I'd go with Richard's suggestion of the park switch on the wiper motor first. Dead cheap and easy to change and with that open exposure the contacts are always corroding throwing up all sorts of anomalies in use!

Sorry but the park switch is not the problem sewin and I didn't suggest it was. Paul has no intermittent wipe and explains the wipers work fine otherwise. This is controlled by the wiper delay relay commanded by selections on wiper stalk.

As RichardV6 states :
Paul although you have changed the 6 pin wiper delay relay please note that MMC appear to use the standard 5 pin relay base connector with a sixth connection added for the narrower "I" pin. This is the one that accepts the intermittent trigger so worth checking this connection is good as a replaced relay could still leave no connection here and it's a known issue!

I discovered this very issue when I had no intermittent wiper function. If you have removed the relay you must ensure the exrra 6th pin and wire are connected manually.

Paul, have you had chance to check out your wiper delay issue yet? I and am sure others would be interested to know.

Ditto your MIL light issue.

Not had a chance o spend time in the garage yet.
The change in the weather has seen me painting the garden cabin i built two months ago.
Hopefully next week.

Had a chance to investigate the wiper situation.
i removed the steering wheel (needed two g clamps, some 19mm ply and 8mm studding, nuts and tape).
i next took off the cowl over the switch gear.
the wiper switch assembly was only partially available as it clashed with the ignition assembly which i did not want to move at this time.
however i inspected the wires as best i could and upon wiggling the wires (two grey ones)that seem to join the assembly from the stalk internal switching it worked.
Nogging tomorrow so i needed to reassemble to be able to steer.
at least i now know where the trouble is. if it occurs again i can plan for switch gear removal and a proper plug inspection.
meanwhile i have full control of the wipers again.

many thanks gentlemen for the tips and comments.