erratic wipers

car911 · 01-06-2003, 10:40 PM

I've posted on this before but thought I would make another inquiry before seriously tackling this annoying problem on my 84 Targa.

My wipers occasionally come on when the motor is running. Happens usually on damp or cold days. What is interesting is that this seems to happen only when the motor is running. With the ignition on (but motor stopped), this does not happen (but I can activate the wipers normally with the switch). Sometimes, I can stop this behaviour simply by turning off the engine then restarting it again.

So, to me, this would rule out obvious faulty switches or relays since they would cause this behaviour with ignition on regardless whether the engine is running or not. The only other thing I can think off is an intermittent short only when the engine is running???

Lightly holding the wiper switch stalk (but not enough to activite the pump) also stops this behaviour. So it might have something to do with the washer pump switch? (Tho the pump appears to work normally otherwise).

What should I do first - just go ahead and replace the wiper switch assembly? Anything else I can try?

RoninLB · 01-07-2003, 12:36 AM

Quote:

Originally posted by car911
What should I do first - just go ahead and replace the wiper switch assembly? Anything else I can try?

no hard info now.. but I believe there is electrical radiation interfering with something.. I do remember reading about it.. to late for me now, 3:35am.. try finding the info, or remind me later..

car911 · 01-07-2003, 11:17 PM

In the trunk, at the front where the washer fluid pump is located, there is what appears to be a relay. Does anyone know what this is and what it drives???

RoninLB · 01-08-2003, 01:18 AM

Hey car.. still don't have the hard info on your crazy wipers..but , I believe it has to do with the interior brake light gizmo in center of the dash.. in other words try removing the plug.. so it can't possibly have any electric floating around in it.. sounds crazy, I know..but the problem may have to do w/an electric field..that electrical gizmo is a relatively complex integrated circuit.. if it solves your problem you are the first guy that I know of that finally had the problem.. I just did a quick look for hard info and the solution/sorry.. and don't forget to let me know the out come..................Ron

steveW · steveW's Garage

I've got a similar problem, except mine slow down, spped-up and go into imtermitent mode no matter which position they are in when they are switched on.

RoninLB · 01-08-2003, 03:13 PM

Quote:

Originally posted by steveW
I've got a similar problem, except mine slow down, spped-up and go into imtermitent mode no matter which position they are in when they are switched on.

You have a different problem, I think.. since 1977 the integrated circuit has become very complicated.. maybe 6 or 7 feed wires to that center dash brake and seatbelt light.. try removing the plug for entertainment.. but I think you have a different problem.. the wiper switch is somewhat expensive, but the internal contacts can be cleaned and adjusted, somewhat. the switch is a bit complicated.. the off position contacts[good luck finding them] do not kill all wiper power. they have to allow the wipers to reset on the windshield. so those contacts can be a problem. I would probably start with the intermitment wiper motor relay, only because it's easy..also the wiper motor has internal contacts, which are easy to figure out, and can be cleaned and adjusted.. and as long as your in there the wiper mech system can be oiled if you remove the arms and operate while getting oil into the shaft bearings.. not an expert. it's more complicated than routine electrics and not a common problem, so no hard info, sorry........Ron

DJB · 01-08-2003, 04:38 PM

Hi,

I had a different problem on my 86. Here's a few things to try.

The wiper stalk may the culprit, clean it and check the connections and switches.

Also check the additional washer fluid switch, it if is faulty it may cause a wipe and spray.

There is also a relay behind the guages that may be sticking.

Lastly you may try disconnection the very large solid state intermittent wiper controller to see if that fixes the problem. The wipers will still work (not in intermittent mode though) but will not return to the park position. This is located behind the heating system blower in the trunk - good fun to get to.