65 caliente wipes wont shut off

The Era of The Square Body Racing Comets
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bronkntrukholik
Posts: 1
Joined: Thu Mar 25, 2010 12:40 pm

65 caliente wipes wont shut off

Post by bronkntrukholik »

I am working on a '65 caliente conv. that had an under dash fire, i found a '65 4-door comet for all the wiring and parts that i need. Both have the intermittint wipers, i don't know if either worked before or not. I am getting everything working now, had the wipers working at one speed last week, now they won't shut off at all. I tried both switches, tried the box on the firewall also. Like i said, i'm not sure if either workd before or not, Any ideas to check or anything to help me out? thank you.

PLP6400
Posts: 57
Joined: Sat Sep 20, 2008 11:21 am

Re: 65 caliente wipes wont shut off

Post by PLP6400 »

I had that same problem with my 65 Comet. The problem was the wiper motor. 65 Comets with intermittent wipers used basically the same motor as the single speed wiper motor. These motors when switched off and returned to the park position, actually caused an intentional short that tripped an automatic circuit breaker to cut the power to the motor. If the circuit breaker goes bad, you can not turn them off untill you turn the ignition switch off. I switched my intermittent wiper system to one from a middle 70's to early 80's Ford "F" series truck. It is strictly bolt in and looks original, plus it has 2 speeds. Another option is to buy a rebuilt or new single speed wiper motor and see if everything works, if not there are Vintage Mustang vendors that sell an itermittent wiper switch for the singlespeed wiper motor which eliminates the vacuum regulator and hoses. 65-66 Mustang wiper motors and switches are the same as 64-65 Comets and Falcons. The original intermittent wiper system you have now was never very good and had a lot of problems. Mercury only used this system for 4 years. Hope this helps.

Patrick

SASSY
Posts: 4032
Joined: Fri Jan 06, 2006 11:32 pm
Location: Wynndel, BC CANADA

Re: 65 caliente wipes wont shut off

Post by SASSY »

Patrick ,sounds like your the man!
By F series do you mean 1/2 ton like F-150 or the bigger trucks?
Fred
I'd rather do it myself if it's done right or not,,,isn't that what hotrodding is all about?
Mission bc 09/12 (I think)
Roy, Brian n me
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PLP6400
Posts: 57
Joined: Sat Sep 20, 2008 11:21 am

Re: 65 caliente wipes wont shut off

Post by PLP6400 »

It is the same wiper set up for the F100 through the F-350

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tweaked
Posts: 806
Joined: Wed Jun 30, 2004 7:06 pm
Location: British Columbia

Re: 65 caliente wipes wont shut off

Post by tweaked »

Thanks for the good info.
Roger
65 comet 7.61@96mph 1/8
Made in Canada, Built for speed.

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kevinshi
Posts: 184
Joined: Thu Jul 17, 2014 12:56 am
Location: Bellevue, WA

Re: 65 caliente wipes wont shut off

Post by kevinshi »

PSA: A detailed description for installing 1973-79 F-Series or 1978-79 Bronco Wiper Motor + 1978-87 F-Series or Bronco Intermittent Wiper Switch & Wiring Harness was written by Dick Harrington of Comet East under the title Intermittent Windshield Wipers + 2 Speeds. As Patrick described in the work he did, Harrington's instructions imply removing the Comet's (optional) factory vacuum interval system and replacing it with a modern electronic mechanism.
PLP6400 wrote:
Sat Mar 27, 2010 10:30 am
...If the circuit breaker goes bad, you can not turn them off untill you turn the ignition switch off.
Patrick
An additional issue is that the motor's circuit breaker relies on an incoming switched ground (in addition to the motor's chassis ground) - on my '65 this is the white/black wire in the motor's 3-wire plug. Properly stopping the motor is a function of BOTH cutting the 12V+ park power circuit (motor's black wire) AND completing a ground circuit (motor's white/black wire). If this ground fails the motor will continue to run even when the black wire is de-powered (such as when the switch is turned to OFF).

This ground circuit has multiple points of failure:
  • The dash switch has to complete an internal ground circuit while in the OFF position. Hypothetically the switch itself could be broken. Unlikely the culprit for the original post in this thread (since multiple switches where tested).
  • The washer foot pump has a relay with a ground circuit that is completed when the pump is at rest (e.g. not pumped). The wiring on this relay was in a precarious location (in the line of fire for being stomped upon). If either of the two ground wires on the pump relay is broken (or disconnected) then the ground won't make it to the motor (and the motor may never stop even with the switch OFF). Furthermore, a bench test of the system will fail if either the pump is not included or the pump ground circuit isn't accounted for (e.g. bypass the pump entirely). Finally their is an internal switch in the pump's relay (activated by pressing the pedal) that could, theoretically, fail somehow. (To wit: Ya gotta account for the pump when you test these things!)
  • While in intermittent (interval) mode, the ground is supplied by the vacuum governor which has a little brass tab on one of the mounting screws to ensure a solid chassis connection (ground). If the Governor is not grounded then, while in intermittent mode, the motor may start but never stop. However this condition will be corrected by a properly functioning dash switch (e.g. moving the switch to OFF will properly park the wipers even if the governor's ground is bad).
Thanks,
kevin
1965 Caliente Convertible
5H25A525287 (76DM6204L5416)

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