Electrical gremlins

[RadioFlyer90]

Hi again- My wife has had her '98 Camry for several years now and it has been a great car. When she first got it, it had (and still has) a an electrical quirk- when you pull on the stalk to run the windshield washer, the doors lock or unlock. This was a slight annoyance, but not scary enough to attempt fixing. Then, the backlighting on the factory radio began flickering when the dash light dimmer was not on full brightness. Again, just an annoyance but not apparently unsafe. Now, I am noticing that when I step on the brakes, all of the lights dim momentarily, especially when the high beams are on. This worries me as my wife has to make some rather long drives by herself on a regular basis and I don't want the lights to quit on her. Could all of these problems be related? Has anybody known of a trouble area in the wiring of these cars? I am basically my own mechanic, but the thought of tearing into the dash to find some problem wires is pretty scary, unless I can get an idea of what to look for.

[dc_98_cam]

Where was your Toyota made ... Japan or Kentucky?

Problem #1: The window washer and door lock/unlock mix up
There ought to be one solid green and one solid light green wire ... controlling the door lock mechanism ... traversing under the dash from the passenger side to the driver side door. ... Guessing that one of the window washer ground wires has rubbed up against these and is grounding out the door lock control ... which is what operates the master door lock control function.
As a repair, if you can locate the green and light green wires under the dash ... not sure but they might be going across the steering wheel column ... then get a length of plastic wrap type wire protector from the parts store, and see if you can get it to slide onto the green/light green wires... particularly in the vicinity of the steering column. ... Just curious, which speed comes on when the window washer comes on ... or is it actually the window washer spray pump?

Problem #2: Dash Light dimmer ... Buy a spray can of electrical contact cleaner from your favorite electronics store. See if you can get a little of the contact cleaner into the dimmer control switch ... not sure but the problem might be an accumulation of humidity or moisture. ...If it really bothers you ... find a salvage yard to get a replacement dimmer switch.
Apply contact cleaner liberally to all connections .... can't hurt anything.

Problem #3: All lights dimming .... This is a general electrical problem related to the battery and alternator. First, remove the negative battery cable ... then positive battery cable ... clean both battery and cable terminals with a small fine wire brush ... until contact surfaces are bright and shiny.
Remove alternator connections ... the plug and also the ground wire, clean as necessary with wire brush and contact cleaner. Reassemble alternator connections, snugly reconnect positive battery cable, and finally reconnect negative battery cable ..... snugly. If you still have the light dimming problem, you will have to get the battery and alternator tested professionally ... either remove from car, or take to shop with adequate test facility. ... Usually the test is free ....

So... altogether there should not be too much difficulty here ... Do you think some of the electrical problems could be related to local weather ... rain or humidity? .... It is usually a good idea to remove the negative battery cable when you are not sure what is going on .... Will be looking for any new developments.... hopefully no surprises.

[RadioFlyer90]

Thanks for the detailed response! I might be able to make some progress with that info!

Answer 1. When I pull the windshield washer switch, the pump comes on and the wipers make one pass at regular speed. And the doors lock.

Answer 2. It was cold and snowing the first time the lights started dimming. The car had sat in the snow for two weeks without being started, but started up just fine when I got back to it.

[dc_98_cam]

Originally Posted by RadioFlyer90

Thanks for the detailed response! I might be able to make some progress with that info!

Answer 1. When I pull the windshield washer switch, the pump comes on and the wipers make one pass at regular speed. And the doors lock.

Answer 2. It was cold and snowing the first time the lights started dimming. The car had sat in the snow for two weeks without being started, but started up just fine when I got back to it.

No. 1 problem just sounds like the door lock wire is grounding out whenever you cause a movement in the windshield wiper/washer switch. If you get a length of the plastic insulating guard .... whatever the parts store calls it... and can slip it up over the steering column area ... along both of the green and light green wires ... Not sure how difficult that will be though. There is one type of the wire guard material that has a slit along one side, that might be the easiest to get in place.

No. 2 problem just sounds like a weakness in the battery storage capacity... either due to age, cold, or the alternator not working, or not having a sufficient amount of operation to charge the battery. ... If nothing else, always look for cable and battery terminal connections that are not impeccably clean.