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Discussion Starter · #1 ·
This is probably a question that cant be answered but you dont know until you try. Is there a exploded veiw out there of a 85-87 vette that shows all chassis, engine, and battery grounds in prospective to the car. having a couple of electrical problems and want to rule out all possible grounding issues. hatch release wont work. have power running to the switch on one side and then it transfers to the other when the button is pressed in . the relay in the back has three prongs going to it. to of which have power and the third when it receives power pops the hatch. i pulled the plastic cover off of the relay and can pop the hatch by pressing the tab on the top of the relay to make the connection but it will not do it by itself. Also wipers are not getting any power. please let me know if anybody has any ideas. I would like to diagnos the problem before i spend 20 dollars on a relay i dont need. Thanks!
 

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do you have access to a factory manual ?
I can look in my 86 manual but don't have a way to post pics.....
 

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hatch release relay has three prongs going to it.
2 of which have power and the third when it receives power pops the hatch.
Power goes to relay 1st , then in order for the the hatch relay to operate the solenoid , the relay is grounded back at the switch(s)

Org @ relay should be hot (key off )
Grounding the brn/wht wire ( which will as you say be hot ) should make the relay operate; if it doesn't buy a new relay.
If the relay works then start checking the 3 hatch switches go to ground.
 

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Discussion Starter · #7 ·
For the rear hatch release. i have repleced the fuse, circuit breaker, and relay. I figured it wouldnt hurt since they were 26 yrs old. the relay has constant power to the orange wire, and brown wire at all times. To rule out a bad ground i stripped the black wire and put it on a direct ground to the battery and chassis . When i press the hatch release button power all of the power remains at the orange and brown wire. nothing changes at all as far as power to the relay. So i figured it to be a switch which i had a spare. I changed the switch and i dont think i even had to. i have power going to the switch and when the button is pressed it transfers over and works properly. It has me completlty stumped . the orange wire should always be hot , which it is. the brown wire is connected to the switch which is a tan w brown stripe and then turns to brown back by the relay. and the black wire is ground. i have no idea why the brown has power without the button being depressed. Also my hatch ajar light not working on instrument cluster.

Ps. not even looked at wipers yet
 

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To rule out a bad ground i stripped the black wire and put it on a direct ground to the battery and chassis . .
It has me completlty stumped the black wire is ground.
Didn't read what I said did you?
The relay is grounded by going through one of the switches.

The black is the power feed to the solenoid , if your relay had activated while you had that grounded it would have been a direct short and taken the fuse out
 

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When i press the hatch release button power all of the power remains at the orange and brown wire.nothing changes
i have no idea why the brown has power without the button being depressed.
Auto Elec 101

Relay control power goes from the battery through the relay to ground. (In this case the relay control power supply is also the operating power for the solenoid)
The operating switch can be on the supply wire before the relay or on the wire to ground after the relay which is how it is wired in this case.
That is why the brown is always hot

i have power going to the switch and when the button is pressed it transfers over and works properly.
IF as you say you have power at one side of the hatch switch do as I previously stated and check the switch ground
Put a known ground on the cold side of the side and see if it works
 

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Discussion Starter · #10 ·
I put a known ground to the one side of the switch and it popped. Bad ground somewhere I take it. Any ideas as to where the ground goes. Thanks for all the help
 

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Any ideas as to where the ground goes.
Time to buy a FSM.

Hatch switch in console goes to ground through the park brake.
If the PB brake is not on or the PB switch is faulty then you won't have a ground circuit.

Ditto the hatch switches on the doors, they ground through the door ajar switches ; a faulty switch -no ground path
 
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