Ground question
Thread Starter
Instructor
Joined: Apr 2009
Posts: 186
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From: Pensacola Florida
Ground question
74 coupe--wipers and a/c fan only run with hood/door open. I have searched the archives and guessing its a ground. Does anyone know of or have a pic of the ground that goes to the bellhousing area. It seems to be a fairly common thing among the c3's. I am going to chack and see if it is accidentally connected to the starter. Any help is appreciated
Thanks
Frank
Thanks
Frank
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I don't have a picture handy, but if you follow the harness down to the starter there is a black wire that comes out with the rest of them. It had a 3/8 lug on it -- that's the one that goes to the bell housing.
Le Mans Master
Joined: Aug 2006
Posts: 7,417
Likes: 1,554
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Wiper problems.
If the wipers work with the door open then the wiper switch is back feeding a ground thru the courtesy light switch. The original dash ground is hard to get to, try attaching a wire from one of the screws that are on the back of the wiper switch to a good ground.
http://s243.photobucket.com/albums/f...=dashwires.jpg shows the original ground for the dash wires, it's the wire that connects to screw #2. PG.
http://s243.photobucket.com/albums/f...=dashwires.jpg shows the original ground for the dash wires, it's the wire that connects to screw #2. PG.
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
also check for your body Gnd. it's a small gnd. braid located app.
where your left foot would rest when seated,
under the car connecting the frame to the bird cage.
where your left foot would rest when seated,
under the car connecting the frame to the bird cage.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
74 coupe--wipers and a/c fan only run with hood/door open. I have searched the archives and guessing its a ground. Does anyone know of or have a pic of the ground that goes to the bellhousing area. It seems to be a fairly common thing among the c3's. I am going to chack and see if it is accidentally connected to the starter. Any help is appreciated
Thanks
Frank
Thanks
Frank
cc
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Sounds to me like the blower and wiper are grounding through the alarm wiring . To get them to work are you saying you have to have the hood "AND" the door open or just the hood or one of doors ? Does your alarm work ? Is the key on the fender in the ON position ? When the blower is running does it cycle on and off if so its grounding through the alarm flasher. So many questions !!!!!
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The blower motor and the wiper motor (the one that plugs in to the spade on the washer pump) and the alarm switch all share the same ground on the 1974. I think Dwnnchs and the OP have nailed this problem, you probably have a wire cut or off the car and the two motors are searching a good ground. When you shut the hood the switch is opening and you lose the ground.
Willcox
Willcox
Last edited by Willcox Corvette; Jul 26, 2009 at 07:21 PM.
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Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
One more little thing,when Willcox mentioned the 74 ground sharing and the possibility of wire cutting or altering I ran to get my one and only 1974 DocRebuild diagram (yes I took it to Florida with me) to look at the seat belt interlock wiring and sure enough the interlock relay shares this common ground. Some of these interlocks have been jumpered. Try attaching a tempoary ground wire from the black ground wire at the wiper motor to the engine and see if that fixes things if so go looking for the black ground wire down around the starter.
Here is a pic of Duke94s starter showing the black wire attached to the starter bolt.
Here is a pic of Duke94s starter showing the black wire attached to the starter bolt.
Last edited by ...Roger...; Jul 26, 2009 at 07:35 PM.
