Wipers.

[trv8]

Got caught in the rain yesterday [:(] and my wipers would only work on position 2/speed 2 and would not return to the park position when turned off unless I timed it right. Also when you press down for the brief use of the wiper, that doesn't work either. Does this mean a new wiper switch, or can they be taken apart and cleaned-up, or is it something else.
I'm a bit dull when it comes to anything electrical [:I].

[UKPhilTR7]

I had this situation before I took my engine out. I cleaned the contacts on the stalk and this did not seem to make much of a difference from what I can remember. I did have a play about with the parking switch and the grease in the motor and from what I can remember this did help.

Please excuse my bad memory on this, but it was before my major engine issues showed up [:D]

[Rich in Vancouver]

I had a similar problem and it was caused by the parking switch on the motor. It needed a bit of adjustment. Also, when I took the lid off the motor I found the grease inside had hardened with 35 years of use. The motor is much happier with it's new grease!

1975 TR7 ACL764U

[FI Spyder]

Yes, the parking switch can be adjusted with system in place. I took out the rack to clean and regrease with clear synthetic grease as well as in side gear case. Can only allow the motor to turn with less resistance and less current draw. Be careful with parking switch actuator though. It's copper and I cracked mine when it got caught in parts washer and although I soldered it, it broke on a club run when it was raining and the wipers wouldn't turn off. Had to disconnect connector under steering wheel. I was able fix by resoldering with reinforcing with copper strap. It needed a small adjustment to parking switch which was done with system in place and motor unbolted for access to screws that hold switch.


TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[trv8]

Cheers guys, I'll be having a bash at this tonight.

[PeterTR7V8]

I found this thread while looking for info on the wiper parking mechanism. FI Spyder's post told me what to look for but I thought a few pictures would shine some light on the subject.

When the wiper arm cable gets moved in & out by the wiper gear it also moves a plastic switch actuator up & down a groove.




Attached to the back of the gear housing is the wiper parking switch. The moving part is a plunger that breaks a contact inside the switch unit when pushed. The pushing is done by the plastic actuator when it slides over it & a movement of about 2mm is enough to break the contact. To do this the plastic slider needs to be more than 1/2 way over the plunger. The adjustment is made by loosening the switch unit & sliding it left or right.





As far as I can figure out, the motor has power until the plunger switch is plunged. The motor has three brushes so the one of them must be live even when the wiper switch on the column is in the off position & only stops powering the motor when the plunger breaks the circuit, yes? I've just spent a couple of hours testing & adjusting but my auto-parking still doesn't work so the only thing I can think of is that the 3rd brush isn't getting the 12v needed to keep the motor turning when the column switch is off.

After some more testing I can confirm that the green wire on the loom plug is live when the ignition is on but there is still no circuit from that connector on the park switch being made to the 3rd brush. Conclusion, the switch is bagarap (as they say in PNG) & since it doesn't work anyway I broke it apart & found that the copper leaf spring that's connected to the plunger and was supposed to maintain the contact with the fulltime power supply was being overpowered by the spring that keeps the plunger in the up position so it was never on. There's no way to fix it so I'll be hitting up the usual sources for a replacement. It has been pretty chewed up by battery acid anyway.



That's probably why your wipers don't park either.



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[trv8]

Nice one Peter.
Strange how things look so much easier to do with a few pictures [:)].

[john 215]

Hi,

Great pictures Peter, these park switches were a real common fault 'back in the day' as the same system was fitted to most BL products.

Would be nice if we had a seperate section for 'articles' like yours and my learned friend Jclay and others have done over the years. To save having to search the whole forum.

Cheers John

LIVE LIFE A QUARTER OF A MILE AT A TIME!
1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

[jclay (RIP 2018)]

Done!

Please note that this is a new URL as Apple has reinvented the wheel . . .er? WEB!

http://web.me.com/jclaythompson/Technical/Wiper_Park_Adjust.html

Clay

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[PeterTR7V8]

Thanks Clay. I feel like I've been upgraded. [8D]

I swapped the whole wiper motor unit for one that looked a lot cleaner on the inside & now I have wipers that know when to stop! This is one of those things where I never knew I was missing something until recently. None of my other 3 Triumphs had self-parking wipers so didn't expect the TR7 to be any different. Can't wait until it rains intermittantly now.



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548