Delay Wipers = weird

[PBJ2500CTD]

OK. After re-reading the initial issue and going over the schematic with several scenarios, I lean more to the wiper motor run/park switch. Just need a little more troubleshooting. Still would like to swap the relay just for grins, and it is easy to do without tools. Since a number of the other functions seem to work as advertised I am less inclined to believe the relay is bonkers...

1. in normal mode what happens if the wipers are switched off at various wiper positions as they begin their ascent, 1/4 way up, 1/2 way up, 3/4 the way up, straight up, and the corresponding descending positions. Test several times.
2. In intermittent mode is the knob able to adjust the variable timing and do the wipers always stop in the same position.

In the normal mode power is applied directly to the motor, causing full rotations and cycling the run/park switch. The run park switch has no effect on the circuit until the power is switched off. At that time the position of the motor run/park switch determines the if the motor is or is not near park. If it is not in or near the park position power goes through the R/P switch and through the closed contacts of the wiper relay switch, through delta circuit "B" to splice S203, through the OFF closed contacts (left circuit of switch) of the multifunction switch, then through contact 1 of the right circuit of the switch, through S202, to the motor slow speed circuit. Once the motor reaches the park position the motor R/P opens up and stops the motor.
In the intermittent mode the wiper relay is briefly energized by the CTM and sets the motor in motion. The R/P switch goes through one cycle and stops in the park position until the CTM energizes the wiper relay. The R/P switch is used for the full cycle in the intermittent mode and if there is a dirty or open position it will loose power and stop until the wiper relay is again energized and the wipers move until they reach the bad part of the contact strip.
I left a lot out since certain functions appear to be working properly. Just need to confirm the steps above. Hope I made sense.

 

[PBJ2500CTD]

Hmmm. I don't think the relay controls the delay function; those relays (of the same size/footprint) are all interchangeable, so it's easy to test.

The CTM should only power the wiper long enough to get it started; the motor should have an internal circuit to power itself until it reaches 'home'. Note the diodes in the diagram; they're a strong hint that voltage/current from the motor must needs be blocked.

I suspect the culprit is the wiper motor because only the motor itself knows 'where' it is and when to stop. It almost certainly has internal low-tech 'rotary' circuitry to keep the motor powered until it reaches 'home'. If your wipers 'hide away' (park) behind the hood, there's a separate circuit and internal control to make the wipers do this. If you open the wiper motor, you'll likely find that the contact surface that keeps the motor powered until it reaches 'home' has a break in it that causes the wiper to stop mid-stroke.

^^^^^I agree 100%^^^^^

 

[PBJ2500CTD]

fest3er,
I believe the "diodes" you are referring to, the A,B and C in the triangles are annotations that the circuit is carried to or from another diagram where you would be able to readily pick up the circuit point, such as shown on the two pages that Dave supplied.

 

[fest3er]

No. Look at 8W-53, inside the 'wiper switch' block. Those little black triangles are, I believe, diodes to keep the wiper from back-feeding other things on the circuit, and to keep other things from feeding power to the wipers. (If they are diodes, the symbol is incorrect.) On the '69 Polara wagon Dad had, if you turned on (IIRC) the wiper, 4-way flashers (or turn signal), and stepped on the brake with the key off, the wipers would move when the flasher was on, and stop when the flasher was off. Correctly placed diodes would have prevented this.

The diodes are needed because the wiper motor gets power from two places: the switch and itself. Turn the wiper on and right off; it continues to operate even though you turned the power off. When self-powered, the wiper motor could power other things on the same circuit. The diodes prevent that from happening. *If* the circuits work as I suspect.

 

[DavidC]

Then why would they work normally as Joe stated ?.

Dave

 

[PBJ2500CTD]

Those are switch contacts for the variable resistor. You'll see them in the relays and wiper motor park/run switch, too. Only smaller.

 

[DavidC]

Joe,swap the relay as stated in post 5 and 10. Let's at least get that out of the way and see what happens.

Dave

 

[PBJ2500CTD]

Then why would they work normally as Joe stated ?.

Dave

That's why I suggested to turn them off in various positions. If the open is early in the wipe cycle and the wiper switch is turned off after it passes the bad section it will not affect the park mode as the park/run switch is a circular contact with two open spaces. When the wiper is turned off the switch positions determine the power source and when the switch in the wiper motor reaches the park position it removes power and stops the motor.

 

[DavidC]

Diode symbol

 

[DavidC]

Found this on a Dodge forum. I would really be surprised if it is the internal switches but you never know.

I had the same issue as you guys. Low and high wipers worked fine. Intermittent was all over the place. on once. on 3-4 times. doesn't work at all.

After replacing the switch and the relays in the fuse box (which didn't do anything), the issue was simply dirty connections inside the motor assembly itself. There is a cover? or casing you can easily remove, I cleaned up the connection points as "osufans" stated, and they work just fine now.

 

[DavidC]

This is on a 3rd gen but same principle
https://dodgeforum.com/forum/3rd-gen-ram-tech/336854-intermittent-wiper-diy-fix.html#post2869375

 

[PBJ2500CTD]

This is on a 3rd gen but same principle
https://dodgeforum.com/forum/3rd-gen-ram-tech/336854-intermittent-wiper-diy-fix.html#post2869375

This is a good example of what the switching circuit looks like. It acts like a brush, or slip contact and energizes the circuit for the duration of the trace arc. If the trace is worn or dirty/corroded it would be like an open circuit and cause the motor to stop at that point of contact.

 

[PBJ2500CTD]

Th

Then why would they work normally as Joe stated ?.

Dave

That is a very good question and piqued my curiosity as to what condition would cause it to "appear" to work correctly in normal mode and to fail in intermittent mode. The relay should be good since it activates the intermittent cycle through one set of contacts (NO) and is used in the park cycle (NC). The CTM controls the timing aspect for the wiper relay. The normal cycle bypasses the park circuitry until the power is removed via the wiper switch. When the wiper switch is turned off alternate power is routed through a closed contact in the off mode of the wiper switch. The wiper relay and wiper motor's rotating switch use the secondary power source to keep the motor running until the slip connector of the wiper motor switch reaches the open circuit of the arc causing the motor to stop. The intermittent cycle starts the motor rotating through the brief activation of the wiper relay. Once the wiper motor begins rotating the park mode is engaged. So you get one swipe at the interval determined by the position of the variable resistor in the wiper switch and CTM timing circuits, causing the wiper relay to energize then de-energize over and over. So the park circuit/wiper motor rotating slip switch is used fully and extensively in the intermittent mode. The only difference in the modes would be when the wiper motor rotating slip switch is used. In the scenario given in the initial posts the most likely event is the contact arc is dirty/corroded at a point that is outside of the point where the wiper switch was manually turned off so it would park correctly. By varying the placement of the wiper switch to the off position related to the wiper's arc position the chance in finding the bad spot is increased in the normal mode. Hope this helps and didn't put anyone to sleep.

 

[PBJ2500CTD]

Found this on a Dodge forum. I would really be surprised if it is the internal switches but you never know.

I had the same issue as you guys. Low and high wipers worked fine. Intermittent was all over the place. on once. on 3-4 times. doesn't work at all.

After replacing the switch and the relays in the fuse box (which didn't do anything), the issue was simply dirty connections inside the motor assembly itself. There is a cover? or casing you can easily remove, I cleaned up the connection points as "osufans" stated, and they work just fine now.

Yep. This is the wiper motor park switch. The biggest cause of wipers not parking correctly. A little more detail is presented post 33. I bet one cool, delicious cyber beer that Joe's issue will be resolved as long as the cleanup will work. If the trace/contacts have been burned up or worn out completely a motor change is required. That was the case with my 92 Dakota...toasted trace. Previous owner probably attempted too many ICED to the windshield starts.

 

[DavidC]

I guess the Service manual t/s section needs amending. Or maybe that's the part "replace motor". Do not try to repair yourself.

Dave

 

[PBJ2500CTD]

I guess the Service manual t/s section needs amending. Or maybe that's the part "replace motor". Do not try to repair yourself.

Dave

It's the replace motor (and linkage assembly) in exchange for an exorbitant amount of clams...
I prefer fix it for greasy fingers.

 

[Joe Mc]

Wow you guys are all AWESOME = Thanks!
Here's where I'm at presently:
1- Picked up new relay.
2- Tested old "original" relay (as outline in SM) it tested OK. "However", SM indicates coil should be 75 +/- 5 Ohms, old relay read 74.1, yes "OK".
3- Tested new relay, coil was 80.1 Ohms.
4- Removed cover from old relay to look at contact points = a). normally open side - both contacts were nice and shiny/smooth b). normally closed side - stationary contact had a divot/pit and the pivot/arm contact had a protrusion/bump matching the divot/pit.
5- In PCM I checked contacts/forks for Wiper Motor Relay which were clean and shiny.
6- Installed new relay and started engine.
***- I've had a suspicion that when the grid heater is on there's slightly less voltage being supplied to the electrical systems and this might be part of the reason why I'm having electrical gremlins (grid takes quite a bit of power as obvious by the volt gage in dash = fluctuates down to about 10.5v or so and when grid goes off gage needle climbs back to 14+, then next grid cycle the needle will drop but not as far down, maybe to 12-ish).
7- As grid was off and volt gage was normal I turned on delay wiper to high (highest speed delay) the wipers came full up then full down and parked twice.
8- As grid came back on the wipers went full up and on return to park (about ¼ way from full up) they paused for a split second and went to park position.
I observed the delay of the wipers work fine while grid was off and pause slightly when grid was on.

I didn't want to mention, but, for quite some time now I've had other electrical oddities, such as:
1- With a CD playing in the middle of a song it will sometimes just stop and restart. In the past I've thrown a few CDs out that, even after cleaning them, I figured were just old. Recently when this (stop/start) would happen I'd press the volume button to display the counter (vs. clock), then rewind 5-10 seconds and let the CD play, it wouldn't stop/skip at the same spot or even in the same song. I have a cleaning disc for the CD player and use it fairly regularly (of course cleaning disc after each use per instructions) and over the years I've taken radio out of the truck into the house and took apart to "deep" clean (if you will) so the player is not dirty.
2- Sometimes the radio display will not light or be very dim, the lights on the channel buttons (1,2,3,4&5) will often not illuminate or sometimes only the 1 & 5 will light, however the 3 slides for the EQ always illuminate. Seems odd that sometimes the display will be fine and after driving a while it'll go out "and then" after driving a while it'll come back on and stay on for entire trip.
3- If I don't push and hold the cruise on button sometimes it won't come on/won't work. Often times if I hit the cruise cancel button it stays at speed sometimes even after hitting it multiple times. Here's a crazy thing; when I hit cruise cancel and it doesn't cancel, if I hit the brakes (it always cancels when I hit brakes) and hit the "resume" button wait for speed to increase then hit the cancel button = it cancels????
4- Lastly, the radio remote steering wheel buttons don't work and I've replaced the clock spring twice over the years = once with a MOPAR unit about 8 years ago which seemed to work the remote radio buttons for only a few months and another after market clock spring (iCARDI I think) about a year or two ago that worked radio buttons fine until I pulled out of the driveway then it stopped. I've sort of given up on the remote radio buttons but they're a nice feature that I'd like to have working.

I somehow think all the above = delay wipers, radio display & button lights and the remote radio controls are somehow related to either the CTM or (unfortunate) aftermarket alternator that I had no recourse to purchase a few years back as the original went out due to being sprayed with coolant from a water pump leak = all this as I was on the road at least 150 miles from home. Note: the radio display, button illumination oddities and remote buttons have been problematic for more years than since I installed aftermarket alternator. So, I'm leaning more towards the CTM but can't rule out the alternator all together due to wiper delay situation when grid is on.

Wish I could have rebuilt the original alternator but I was on the road and needed to get back on the road. I did purchase correct manufacturer type replacement alternator = brought original in the store with me to make sure it was correct = I forget DENSO or whatever original one was but did purchase same manu. replacement.

Ain't this fun and really odd = YES odd / FUN not.

Thanks guys.

 

[DavidC]

You really need to get the electrical working right, less voltage = more amperage and more of a chance of arcing contacts causing pitting etc.. This includes relays, switches (headlight for example),AC/heat motors the list goes on and on. I believe you can buy new replacement Denso (foster truck ?). Not to mention the havoc on electronics, PCM, ECM etc. It's just a time bomb ticking.

Dave

 

[Joe Mc]

Dave, Thanks. So you're saying the alternator is the culprit and not the CTM?
BTW: alternator I purchased, although from a chain parts store, was "new" = not a reman unit. I always buy "new" parts, occasional scrap yard stuff but not mechanical parts. Keep in mind the radio display, button illumination, remote radio buttons and cruise anomalies mentioned were happening pre-alternator replacement.

 

[DavidC]

That's hard to say. Your dealing with the CTM electronics but if your having gremlins The alternator is the place to start, have you checked the AC ripple from the alternator ?. That would be the first test as you may have bad diodes causing less amperage available for the load. I think I have posted that test here somewhere. If not I can find it for you or maybe Bruce can. I have to get ready for my glow in the dark treatment right now so let me know and I will look it up when I get back.

Dave