Strange Wiper/Speedo/Trans Problem

[53effie]

Hello folks,

I have a 1999 Ranger XLT regular cab longbox with the 3.0 and automatic transmission. For a little while now, the intermittent feature of the wipers has not worked properly, and the windshield washer squirters have not worked at all. When I say that the intermittent settings do not work properly, I mean that they either don't work at all, or when they do, the wipers seem to select an arbitrary delay and then stick with it no matter what position I have the switch set to. Recently though, I had an instance where the wipers were working on intermittent and just before the wipers would start their sweep, the speedometer would drop to zero and then return. At that time, and maybe it was a coincidence, the truck seemed to keep dropping in and out of passing gear. Does anybody have any idea what might be going on? Any help would be greatly appreciated.

Thanks in advance.

Glen

 

[Earl43P]

Not much in common with those 3 functions.

The grounds involved (G102, G103 and G105) are on the front inner fenders and the one on the firewall between the PCM and the blank plate (dead center is G102, used for the VSS signal to the PCM).

G103 is driver side inner front fender, last one aft, about where the front of the fusebox is. Used for the wiper motor and right door ajar (see if that works) and tachometer and 4WABS (not RABS).

G105 is on the passenger side inner fender, just forward of the heater blower. Used for the VSS signal to the Cruise Control and ground for the washer motor.

Might try cleaning those up.

The multifunction switch (turn signal stalk innards on the steering column) are a frequent problem which could account for the intermittent wipers and washer, but has nothing to do with the speedo, which IS why it is dropping out of OD (loss of speed info to PCM).

When you clean those grounds, note that on the sheet metal side, all you need to brighten up are the three raised dimples that the ground lug rests on. Obviously, you also need to brighten up the ground lugs that contact those raised dimples.

I would suggest having the alternator tested. Whacky things can happen with a bad alternator, particularly if the diode trio is bad, passing some AC voltage into your DC system. Most parts stores will test that for free, but most have no clue about the AC part. Use a multimeter set on AC volts for that.

Best guesses I got!