Wiper motor test?

Gotta love that wiring . . .
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70spider
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Your car is a: 1970 Fiat spider
Location: N.E. New Mexico

Wiper motor test?

Post by 70spider »

Is there a way to bench test the wiper motor? It is a 1970. The reason I ask is I took it apart and and cleaned it but think the wiper cycling relay switch is the bad part in the system. So if I can test the wiper motor I can eliminate it as my issue.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
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Re: Wiper motor test?

Post by 18Fiatsandcounting »

The wiper motor casing is the ground, and if you put +12V on the light blue wire, the motor should run at full speed. The light blue wire comes a red wire inside the motor assembly.

-Bryan
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70spider
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Re: Wiper motor test?

Post by 70spider »

Thanks I will give it a go.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
spider2081
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Your car is a: 1981 Spider 2000
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Re: Wiper motor test?

Post by spider2081 »

I have never owned an early spider
I think that early spider wiper motors have a electric field where the later spiders have a permanent magnet field.
The early wire diagram I have shows the wiper motors had a rheostat on the dash to control the wire motor speed. Later Spiders have a speed switch to select fast or slow speed. The rheostat controls the field current.
I'm guessing the field circuit on an early wiper motor might need to be powered for the motor to operate properly. (light blue wire, INT terminal on the motor) as well and the main power wire to the motor (light blue/black wire, C terminal) This power comes from the wiper switch on the steering column.
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70spider
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Re: Wiper motor test?

Post by 70spider »

spider2081,
Yep the system on my spider is a bit complex. At the moment I don't have 12v powering the circuit so I have to do some tracing. It is not important, just thought I would try to get it working, it never has worked.
Thanks for the help.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
spider2081
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Your car is a: 1981 Spider 2000
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Re: Wiper motor test?

Post by spider2081 »

I think I miss stated in my previous post. Looking again at the wire diagram I'm thinking

I think power to the steering column switch comes from fuse 2 or the second fuse from the steering column., When the steering column switch is in any position other than full up, and the is battery connected power should be measured on the INT terminal of the wiper motor on the light blue wire. I believe the rheostat completes the ground circuit for the electric field. I'm not positive about that though. I think if the "D" terminal of the wiper motor is grounded the motor will run full speed as it is getting power from the light blue wire on the "INT" terminal and ground from the "D" terminal.
maybe someone else can confirm this.
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70spider
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Re: Wiper motor test?

Post by 70spider »

Yep that sounds about right. I have been dissecting the wire diagram and isolating what I need to check. I'll start with the #2 fuse and go from there. Thanks
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
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70spider
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Your car is a: 1970 Fiat spider
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Re: Wiper motor test?

Post by 70spider »

Well I have no power on circuit #2. Also, no power on #'s 3,4,5,6,7, and 8. Only #1, #9 and #10 have power. Could it be the fuse box? I just replaced it a year ago but it did get wet a few months ago. So how exactly does the Fiat fuse box work? Does each circuit have its own power source or are they shared. My only concern at this point are getting the headlights to work.
Thanks
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
18Fiatsandcounting
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Re: Wiper motor test?

Post by 18Fiatsandcounting »

Here's a quick summary of where the 10 fuses get their power:

Fuse 1: From a large black wire to the starter motor post, so this always has power and sounds OK on your car.
Fuse 2: From a blue/red wire from the INT terminal on your ignition switch, so this may have an issue.
Fuses 3,4,5,6 are the headlights, low and high beams left and right. Power comes first to the outer lighting switch on the dash, then through the stalk switch on the steering column.
Fuse 7 and Fuse 8: Power for these is from a white/black wire from the outer lighting switch on the dash.
Fuse 9 and Fuse 10: Power for these is from a large pink wire from terminal 15 on the ignition switch.

With the exception of Fuse 1, all other fuses are only powered when the ignition switch is turned on.

Based on what's going on with your fuses, my guess is that there is an issue with the outer lighting switch on the left of the dash, or the wiring to that. Occasionally the switches go bad.

-Bryan
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70spider
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Re: Wiper motor test?

Post by 70spider »

Bryan, thanks I think I got it. Now I just have to put the dash back together.
1970 Fiat Spider 124 Sport aka "Pesto"
2002 Mazda Protege5
2013 Buddy 170i
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