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1998 Ford Ranger No wipers, some of the time

Tiny
GIBBYPLEASE
  • MEMBER
  • 1998 FORD RANGER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 133,500 MILES
I've had this 98 Ford Ranger for about a month. The wipers do not work in the morning but will work in the afternoon and evening. Engine temperature doesn't seem to have much to do with it.

I've already installed a new multi-function switch, and I've replaced the fuses in the interior fuse box.

I have no other electrical problems to report. All the other signals, etc. Seem to be normal.

Is there a relay somewhere that I'm missing? What else can it be?
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Friday, August 7th, 2009 AT 11:17 AM

11 Replies

Tiny
IMPALASS
  • MECHANIC
  • 3,112 POSTS
Hello -

That is kind of strange. . .. . .. . .isn't it.

To better assist you what is your engine size in liter and the 8th digit of your VIN.

Okay, your model does have a CTM. . .. . .Central Timer Module. The function though is it regulates the wipers according to the speed you are traveling from what I can see and when the wiper switch is activated, the CTM receives a signal from the wiper switch and activates the wiper high/low relay, wiper run/park relay or washer pump relay.

It is located behind the center of the instrument panel.

Let's check a few other things first though if that is okay.

Please go to Auto Zone (AZ) or O'Reilly's (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don't get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

By chance the system may have thrown a code. . .. . ...we are looking for like, B1342 or B1431 etc.

Next, let's check out the motor and relays. . .. . .. . ...

COMPONENT TESTING

WIPER MOTOR

1. Check High Speed Operation - Turn ignition off. Disconnect wiper motor linkage from wiper motor. Disconnect wiper motor harness connector. Using a jumper wire, connect battery ground to wiper motor terminal No. 3 (Black wire terminal). Using a second jumper wire and in-line ammeter connect battery voltage to wiper motor terminal No. 5 (Dark Blue/Orange wire terminal). Wiper motor should operate at high speed and should draw 5.5 amps or less with wiper linkage disconnected. Replace wiper motor is operation is not as specified. If wiper operation is as specified, go to next step.

2. Check Low Speed Operation - Move battery voltage lead from wiper motor terminal No. 5 to wiper motor terminal No. 4 (White wire terminal). Wiper motor should operate at low speed and draw 3.5 amps or less. Replace wiper motor if operation is not as specified.

I know you just replaced the switch but by chance there may be a bad wire. . .. . .. . .here is the tests for the switch.


https://www.2carpros.com/forum/automotive_pictures/248015_Picture1_84.jpg




https://www.2carpros.com/forum/automotive_pictures/248015_Fig_1_7.jpg



You have 3 relays. . .. . .. . .. . ..please test each one. The wiper high/low relay, wiper run/park relay or washer pump relay. I have attached the pic of the location of the relays. . .. . .. . .for ease of viewing it is in two parts though. . .. . .. . .. . ..so make sure you overlap.


https://www.2carpros.com/forum/automotive_pictures/248015_F2_6.jpg




https://www.2carpros.com/forum/automotive_pictures/248015_F7a_1.jpg




https://www.2carpros.com/forum/automotive_pictures/248015_F7b_1.jpg



I will continue to look for any tests for the CTM while you are doing the above. . .. . ..is that okay?
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Saturday, August 8th, 2009 AT 2:20 PM
Tiny
GIBBYPLEASE
  • MEMBER
  • 7 POSTS
Engine size is 4.0L v6. 8th digit of VIN is 'X'.

Yesterday evening, the wipers decided to work again. This morning they did not.

When they work, they work completely normally. Should I assume this means that the motor is okay?

If I suspect the CTM, what is the part no?

Is it sometimes referred to as the GEM?

Thanks very much.
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Monday, August 10th, 2009 AT 1:08 PM
Tiny
IMPALASS
  • MECHANIC
  • 3,112 POSTS
Hello -

Thanks for the info.

If it were me I would first do the tests I suggested above....... Going to AZ or OR for codes, the other tests on the motor and relays.

I suggest this as the relays may be getting worn or defective. The motor may have dead spots in it and that may give us a clue.

DESCRIPTION & OPERATION
Wipers operate at high, low or variable intermittent speeds. When wipers are turned off, wipers will continue to run for a few sweeps until wiper motor parks. Intermittent speed interval decreases with increasing vehicle speed. Speed dependent interval is controlled by Generic Electronic Module (GEM) or Central Timer Module (CTM).
Models equipped with 4-wheel drive or power windows are equipped with GEM, all other models are equipped with CTM. When wiper switch is activated, GEM/CTM receives a signal from wiper switch and activates wiper high/low relay, wiper run/park relay or washer pump relay.

According to the above if you have a 4WD or power windows you have the GEM. You have a 2WD......... Do you have power windows?

I am sorry....... My manual doesn't show the part number for either. You will have to check the dealer for that. I didn't even see it at AZ.
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Monday, August 10th, 2009 AT 10:48 PM
Tiny
GIBBYPLEASE
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I'll do the tests as soon as I can and get back to you.
I don't have power windows.
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Monday, August 10th, 2009 AT 10:53 PM
Tiny
GIBBYPLEASE
  • MEMBER
  • 7 POSTS
"No DTC's are presently stored in the vehicle's computer."

From O'Reilly's scanner.

Wipers are working as of noon. They were not working from 8:45-9:00 am.
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Tuesday, August 11th, 2009 AT 3:19 PM
Tiny
IMPALASS
  • MECHANIC
  • 3,112 POSTS
Hello -

Thanks for the info.........

Okay, then the way I see it your model has the CTM. We may have to replace that but let's do the other tests first to be sure.

No codes..... Okay.........

Have you had time to do the tests on the motor, relays (all 3) and the new switch?

The only reason I suggest the switch too is in case there is a bad wire going to it.....

Once we have checked that then it may point to the CTM.

Please let me know what you find. I am currently having technical difficulty so I will try to get back with you as soon as you reply from this spot while my other station is being worked. Hopefully it will be up soon and I can have all my systems working......... Then I will go back and see what other info I have on the CTM now that we are sure your model has that and not the GEM.

Thanks again for the update.
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Tuesday, August 11th, 2009 AT 8:39 PM
Tiny
GIBBYPLEASE
  • MEMBER
  • 7 POSTS
Well,
Not having confidence in my abilities to do diagnostic work with a jumper lead (and not having a jumper lead around), I took the truck in to a nearby Ford Dealership. They did a recall repair and for $96, were able to tell me that all the relays and switches were fine, and that when they tap on the motor, the wipers come on. So there's something internal to the motor.

They then offered to replace it for me for $420. I'm going to pick up a rebuilt motor from O'Reilly's for $60 and attach it myself. That should do it.

Thanks for your help. If I had any experience with the jumper lead, you would have been all that I needed to get this one solved. I'll be back next time.
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Saturday, August 15th, 2009 AT 8:59 PM
Tiny
IMPALASS
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Hello -

Thanks for the info.........

Hey, don't be so down on yourself....... You did an outstanding job..... Nobody knows everything......... We all have our limitations..... Many shops sub work out due to not having the proper equipment or experience.....

It cost you $96 but your time and worry dealing with it was well worth it.......I think.

You are still saving $420...........

Here is the info on motor removal and installation.

WINDSHIELD WIPER MOTOR
Removal & Installation
1. Turn ignition on. Turn wipers on. Use ignition switch to stop wipers when blades are vertical. Remove wiper arms. Disconnect negative battery terminal. Unplug wiper motor connector.
2. Remove right linkage access cover. Reach through access cover opening and unsnap wiper linkage clip from wiper motor shaft. Push clip away from linkage until it clears nib on crank pin. Disengage wiper linkage from motor crank pin. Remove nuts and wiper motor. To install, reverse removal procedure. Ensure linkage clip is securely seated.
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Saturday, August 15th, 2009 AT 9:33 PM
Tiny
IMPALASS
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Hello,

Hey, one other thing. it also, it looks like you may have some recalls on your vehicle. The dealer may fix these for free. Please contact the dealer service department, give them the VIN number of your car and have them check on these to see if they apply to you.


https://www.2carpros.com/forum/automotive_pictures/248015_Recall_21.jpg


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Saturday, August 15th, 2009 AT 9:43 PM
Tiny
DECASEMAN
  • MEMBER
  • 1 POST
I have an odd pairing of issues. My 1998 Ranger std cab 2.5l 2wd manual has the same intermittent wiper failure. I have replaced all relays and fuse. I have replaced the speed selector on the column 3 times. The last thing I did was to open of the GEM and let it dry out read that somewhere. It's been a year now and it came back today.

The other paired issue is that my dome light stop working at the same time my wipers do. I can be driving down the road with the lights and wipers switched on and nothing is happening. Then all of a sudden the light flips on and the wipers start moving. Then off and on and off and on and so on. No pattern.

I did figure out there is a metallic ping sound that happens when they switch from on to off. Sounds something like what I remember my dad's old 20 foot Ford flatbed turn signal relays used to make. The ping also happens when the car is just sitting there no key in it.

Possibly related is that my aftermarket radio has reset itself 3 times in the 6 years of owning the car.
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Monday, January 4th, 2021 AT 11:04 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
It does sound like a control module issue so let's assume that and try to prove it. Here is a wiring diagram that we need to monitor voltage on.

Basically you have a hi/lo relay and a park run relay. When you turn the switch to tell the GEM to turn the wipers on, it uses the run/park relay to determine if they are moving or not. Then it puts the hi/lo relay in the position of the switch. It defaults to high so when you turn the switch to lo it turns the relay on and it moves it to apply power to the low side of the motor. Then it turns the relay off when it is on hi. So if you are on hi, you should have no voltage from the GEM to this relay.

Let's turn the wipers on low and check voltage at the GEM on the two wires coming from the switch. Then check voltage going to each of the relays at the GEM. The GEM is actually supplying the ground to complete the circuit on these relays but you should have voltage on both when on Lo.

Here is a guide that will help with this:

https://youtu.be/Hlna_kUt7As

https://www.2carpros.com/articles/how-to-check-wiring

Below is the diagram for your use. Let us know what you find.
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Monday, January 4th, 2021 AT 1:41 PM

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