changed wiper motor, still doesn't work

My wipers quit recently so I got a new motor and swapped it out, and after reassembly the wipers still don't work. Several questions:

I wasn't sure how the arm assembly (whatever its called, all the levers and gears under the hood that the arms attach too) should go, and there's a good chance it isn't exactly like it was when I took it out. Could the problem be just that I don't have these things positioned correctly, and the motor is functional but the assembly is binding and so won't move the arms? (I don't think this is the case because I don't see or hear any sign that the motor is even trying to move.)

If not the above, how do I determine whether the motor or my internal wiring is to blame? I recently bought a multi-meter but don't know yet how to use it to test curcuits. There is a 5-pin connector that hooks up to the motor, so I also don't know which wires are supposed to be hot, etc. Can anybody tell me what to set the multi-meter and which holes to stick the two prongs into?

I'm thinking that there's a decent chance my wiring is to blame, because the radio/cig-lighter circuit just went out about 2 months ago so maybe the wiring is getting old and decrepit (I hate that thought).

However, the "new" motor is a rebuilt model from Autozone, and I've had other problems with parts from them, so I wouldn't be surprised if the "new" motor was bad (but, hey, they're cheap, and they eventually get you the right part). If it is, I'd like to be able to prove it to them.

Also, just to cover all bases, the fuse I'm checking is the one labelled "RR WIPER". That is the right one, right? I don't have any rear wipers and don't know what the RR means, but I assume that's the fuse for the wipers (if it's not, there might be an easy solution here).

The wipers work off of a circuit breaker not a standard fuse. Little silver box maybe an inch long and 3/8" wide. It gets kicked on occasion and falls out of the fuse block.

This is for a Renix but likely close to what you have, the circuit breaker is the same, though the location may be different.

Thanks, 8mud, it's often simple stuff like that where I go wrong, that's why I like this message board. I even have the FSM, but didn't bother to check (why they have a live fuse in an inactive circuit is another question). However, now that I check the correct fuse/circuit-breaker, it appears to be okay. The circuit breaker is fully installed in its proper place, and it tests out on the multi-meter as having a connection between the two prongs (so, does it reset automatically? I don't see any knd of reset switch). The only discrepancy is my FSM says it should be 5.5a, while the one in it is marked 4.8a. But that can't be the problem since it worked for so long with it.

So, any ideas on how to test the wiper motor?

to test the motor, connect 12v directly from the battery to the motor.

The breaker automatically resets. 5.5 is correct but as you say, 4.8 should be okay unless the current draw has increased for some reason.

For an initial check I wouldn't worry too much about exact voltages or what goes where. Turn everything on of course, get your negative lead clipped or jammed into a good ground point (you can make sure of a good ground by touching the pos lead to a known source such as your battery positive terminal) and probe the various contacts in the plug with various settings of the wiper switch. If you find no voltage present for any of the leads, you know the problem lies in the wiring or switch. Otherwise make a note of the readings and wire colors and get back or check your FSM.

Do you have intermittent wipers? I had one module fail and still had high and low wipers -- just no intermittent. I believe others have reported other results so you might check that if it applies.

Let us know how you come out.

89xj said:

to test the motor, connect 12v directly from the battery to the motor.

Click to expand...

Connect where and how? The motor has a 5-pin connecter with blue, green, red, brown and black wires. Should I get some response from the motor if I simply connect the red and black wire pins to + and - on a battery? Is it safe to do this directly from the battery, without a fuse/CBkr, or do I risk burning up the motor?

By the way, my wipers do have the intermittent option, as well as fast/slow.

Pelican said:

For an initial check I wouldn't worry too much about exact voltages or what goes where. Turn everything on of course, get your negative lead clipped or jammed into a good ground point (you can make sure of a good ground by touching the pos lead to a known source such as your battery positive terminal) and probe the various contacts in the plug with various settings of the wiper switch. If you find no voltage present for any of the leads, you know the problem lies in the wiring or switch. Otherwise make a note of the readings and wire colors and get back or check your FSM.

Click to expand...

Ok, thanks, that sounds do-able. Okay to use the body as ground point? Also, a super dumb question, but what do I set the multi-meter to determine if there is voltage present? DCA? And if so, what setting, 10A, 200m, 20m, 2000 funky-u? Or, more simply, which is higher, 10A or 2000 funky-u? I presume 10A (and is that amps?).

Or should it be set to the ohms/funky-arrow function? I discovered, by trial and error, to use that section to determine if a connection exists between two points.

Sorry for my ignorance, the multi-meter is new to me. I need to learn how to use it, but just haven't had time yet and it didn't come with much of a manual. There's probably something out on the web (anybody know a good site?). I'll go search now while waiting for answers here. Thanks for the help.



Note: table of electrical symbols used above
funky-u = ?? (millionth-amps?)
m = milli-amps?
A = amps?
funky-arrow = ??
(hey, at least I knew that the funky-fat-upside-down-U was the Ohm symbol)

OK, by experiment, it looks like there are two ways to check my circuits - the DCA setting and the DCV setting.

To do my experiment, I took the external speaker to my ipod, which runs on 4AA batts, and removed one battery. Then I tried measuring across the gap of that missing battery with various multi-meter settings.

Under DCV and a setting of 20, I get a reading of 3.9, so it's measuring 3.9 volts for 3 fully charged AA 1.2V batts, which is correct. So I should be able to use this setting to measure the wiper connection on my jeep and get some number, prob 12ish.

Under DCA and a setting of 200m, the experiment-speaker-batt-gap measures 52, which I guess means 52 milli-amps. I don't know if that's reasonable, but it seems okay. So I presume that on the jeep, this setting should also give some kind of result if the circuits are live.

Strangely, the ohm/funky arrow setting doesn't seem to produce any result, even though there is obviously a complete circuit between the points I'm touching with the probes. I'm guessing that the presence of the other batteries means that there isn't any resistance, though, since that is what I'm really measuring rather than connectivity.

So I'll use the DCV and DCA settings on the jeep then.

Your DCA or DC amps setting is going to be too low on your multimeter or so it sounds. Just check for voltage using the VDC.

As Jeepm@n says, as a practical matter you will very rarely use your meter to measure current (amps) on the jeep. Just forget that setting as you will likely end up melting your meter or at least blowing a fuse (in the meter).

You will use VDC across a voltage source, not in series with a device.

Resistance (ohms) is measured across a device while no voltage is present. Again, as a practical matter, a lot of what you will be measuring with the ohms setting is continuity as opposed to an exact resistance reading. Continuity meaning that there is an unbroken or uninterrupted circuit. Do not measure across a voltage source with the ohms setting.

You mention the "funky arrow" -- this is for measuring diodes. I don't know if your meter has a separate setting for this, but for your immediate purposes just use the regular ohms setting.

Funky u is microamps. m milliamps. A amps

Anyway, sounds like you are on the right track. Use the VDC setting to see if there is around 12 volts present in the wiring to the motor and let us know what you find.

I am sure you can google up some good instructions on meter use with diagrams which make it so much easier to understand. My thought is to just give you enough to get at least headed in the right direction with your wipers.

Weird - I got results, but I don't know what to make of them.

First off, as mentioned, the connector is 5 pins with corresponding wire colors (on the motor side, I can't see the wires on the jeep side without unwrapping the bundle which I haven't done) of red, brown, black, green and blue.

I'm measuring 6-7 volts on the green wire pin with the wipers in any position - high, low, intermittent and even OFF. None of the other pins show any significnat current under any setting, but various pins give an initial reading of negative fractional voltages like -0.2, -0.6, and then start counting down toward zero. The pins that give the negative values seem to differ with setting, but I haven't done it enough yet to determine any kind of consistent pattern.

This is the only change between the settings - one or two will have the weird negative readings while the others have a steady 0.00 from first contact of the probe. But only the green-wire-pin shows any significant voltage.

This is with the ignition switch on but motor not running.

After turning off the ignition, I checked again and the green wire intially showed over 6 volts, but then counted down to zero over about 60 seconds. So apparently once it takes on a charge, it dissipates slowly? That might have fouled up my readings, I guess I'd better go through the cycle again.

P.S. I'd really like to directly test the replacement motor I bought to see if it works, but I'm reluctant to just start hot-wiring it for fear of burning it up. Presumably the green wire pin is the hot wire, but which pin do I run the ground from? And is there a danger of damaging the motor? I suppose I could pull the circuit-breaker and wire it in the loop, with some extra trouble. Does that make sense?

I have an extra wiper motor that probably works, that I took out of a 90 XJ hoping to use it as a backup, only to discover that it has a different plug configuration (6 pins in a different physical pattern). If I don't hear back on a safe way to test, I may try experimenting with that one. However, the wire colors are different so it might not give an answer applicable to my model.

Also, I think I'll run up to the parts store and get a replacement 5.5 amp circuitbreaker. Just in case, and it can't be too expensive.

Do me a favor and check the wire colors on the harness connector for your 92 and not the wiper motor connector. Some after market motors have odd colored wires. On some model XJ's the wires change color three times between the wiper module and the motor.
Are the wiper motor wire colors a match with your replacement and the old one you pulled out?

Is your 90 wiper motor six pin or six wire? I've never seen a six wire wiper motor.

I meant to mention that with a digital multimeter you will get stray readings that will fluctuate and disappear. I'm not sure what these are, capacitance or whatnot, but they meaningless. I assume your meter is autoranging?

I would say first that the liklehood of both your original motor and the replacement motor being bad are just about nil but I guess anything is
possible.

As to testing, I would put a fuse (maybe 10 up to 20 amp if you are using jumper cables) in the circuit rather than the circuit breaker. If you don't have one, get an inline fuseholder when you go to the parts house. These are handy to have on hand in any event. They should have one -- otherwise Walmart in the automotive electrical section.

I agree that you should have some protection in the circuit, not so much to protect the motor but in the event of a short somewhere. I'm sure I don't have to tell you about the awesome results from a direct short across a 12 volt storage battery.

Battery ground to the black wire or probably the metal case if that is easier -- you can use your ohm meter to confirm the case has continuity with the black wire in the plug. Touch the fused positive lead briefly to the green or other leads until you get some reaction. That's what I would do but understand I don't know how these motors are wired -- perhaps someone with more knowledge will chime in.

The first thing I would do though is unplug the intermittent module underneath the dash and plug the cable ends together and try the wipers just to eliminate the possibility that this is the problem. Someone pointed out in a recent post that the two plugs can be joined. That module is right at the bottom of the lower dash to the left of the steering column, held with velcro.

Get back if I have missed anything.

have you tested to see if you have current flowing into and out of the wiper delay module?

i could only find the currect size curcuit breaker at the dealership when i replaced mine in my 89. you could use a wire to bridge the contacts for the curcuit breaker in the fuse block during the tesing if the breaker is bad

8Mud said:

Do me a favor and check the wire colors on the harness connector for your 92 and not the wiper motor connector. Some after market motors have odd colored wires. On some model XJ's the wires change color three times between the wiper module and the motor.

Click to expand...

Here's the wire color scheme, first on the motor side as reported before, followed by the colors on the harness side per your request. Most of the wires on the harness side have different colored stripes.

Wire Color
Motor side/Harness side

Blue / Tan with Red stripe
Green / Green with Black stripe
Black / Black
Brown / Brown with white stripe
Red / Red with yellow stripe

8Mud said:

Are the wiper motor wire colors a match with your replacement and the old one you pulled out?

Click to expand...

Yes, although on the replacement (autozone reman), all of the wires appear to have been painted black. However, it's a sufficiently bad paint job that I can see patches on each wire that match my original in color.

8Mud said:

Is your 90 wiper motor six pin or six wire? I've never seen a six wire wiper motor.

Click to expand...

I was wrong on that, on closer inspection it's actually 5-pin with 5 wires. On the wiper motor side of the connector, there are 3 male pins, 2 female pin-connectors and 2 more holes for female connectors that aren't used, all aranged in a circular pattern. My 1992 model, in contrast, has 5 all male pins in rectangular pattern that has space for 1 more. Also, the 92 pins are much smaller than the 90's.

Wire colors on the 90 are gray, blue, red, white, black. Other than the connector, the motor itself appears identical to the 92 version, and in fact I used the waterproof sleeve from the 90 to replace mine, which had become torn in many places and which did not come with the rebuilt motor.

The wires from the different connectors attach to identical points on the two motors, and it's prety obvious that gray(90)=green(92) and white(90)=brown(92), while all the same color wires attach to the same place. If I can satisfy myself that my original motor really is bad, I'm pretty sure I can take the connector off it and put it on the 90 model and if that works, I can return the replacement motor I bought, or just keep it for a spare.

Pelican said:

I meant to mention that with a digital multimeter you will get stray readings that will fluctuate and disappear. I'm not sure what these are, capacitance or whatnot, but they meaningless. I assume your meter is autoranging?

Click to expand...

Wow, I'm having just a horrible time getting any kind of consistent reading. Scratch all the measures I reported earlier, I can't get anything to repeat.

I got those earlier measurements using a ground on the hood where the little rubber fixture had worn through the paint. I thought it was meaningful because it seemed semi-consistent, with zeroes or near-zeroes on most pins and 6-7 V on the green wire pin.

But I never let the numbers stabilize - the 6-7 V reading was where the meter jumped to when I first connected. But if I hold the connection in place, it keeps moving and counting down toward zero, just like it did when the ignition was turned off - the closer to zero it gets, the slower it goes, but eventually (after like 60-90 seconds) it reads something like 0.02 or 0.03.

When I run a jumper cable to the negative battery terminal and use that as my ground, things get even crazier. Now several positions on the connector jump to various numbers and start counting down toward zero. Then if I break the connection and reconnect, it may read 0.03, and repeat that a time or two, and then the next time it jumps to 8 and starts the countdown routine again. Or 3 or 6 or whatever (never over 12).

The only consistent thing is the black wire now reads a steady 12.42 V, same as the battery itself. Before, with the hood ground, it was reading zero, so I guess that shows that the hood ground wasn't good, so I'll keep using the jumper off the negative battery terminal.

This is driving me crazy. I gotta take a break and eat lunch, then I'll try to rig up some clips or something so I don't have to hold the probes in place with my hands. Maybe that way I can get some stable readings.

I'm not sure but I don't think my multi-meter is "autoranging". I have to choose a setting from the dial with options of 200m, 2000m, 20V, 200V and 500V. I have it set on 20V for these readings.

make sure the battery in your meter is good, and that you haven't blown the fuse in the meter...your meter probes themselves may have intermittent connection...A bad probe will drive you crazy!

20 volts is the proper range setting.

I'm still working on this, but I got side-tracked last night and this morning on other stuff. I'll get back to it soon and hopefully will have mm readings tonight or tomorrow.

BTW, the multi-meter I'm using is a Gardner Bender model #GDT-200A as shown here.

Not real fancy but I think it's a respectable brand. I'll check the battery and do some test readings on simple things to be sure it's working okay, then try again on the wiper motor connections.

Meter looks fine -- virtually any meter will suffice for basic use on our vehicles.

To check it, set to VAC, range over 120 and plug into a home outlet -- should get a steady reading of about 120. With VDC test a dry cell which I think you have already done -- should get a steady reading of 1.5. Test your car battery directly across the terminals -- should get ~12 with motor off and ~14 running. On OHMS touch the leads together -- should get 0.0. A 100 watt light bulb should measure around 9 ohms. Note that when measuring circuits with light bulbs that it will take a minute for the reading to stabilize.

If your meter responds well to these tests, it is okay.

You need to ignore those stray readings that count up or down. A good reading will be completely stable or perhaps move around a tenth of a point or so -- that doesn't make sense -- anyway, say 12.1, 12.0, 12.1 etc.

More later.