What is this wire?
#1
What is this wire?
All, My car won’t start and it’s not even cranking. I think I need a new battery. When I go under the hood to check the battery, I see this little thin ground wire not plugged up. The car ran before and now it doesn’t, but I can’t remember if the little wire was hooked up. There is a thick ground wire from the battery and thin one. Thick one looks like it’s connected to the block. I have no idea where this little think ground wire goes. Should this be connected somewhere?
Last edited by Rosco920; July 31st, 2018 at 05:02 AM.
#7
Sorry about that. I have a 72 cutlass convertible. See the attached pic. Also, I think the battery is dead as no lights come on...not even when you open the door.
I wonder what that goes to. The frame?
I wonder what that goes to. The frame?
#8
A dead battery will definitely prevent the car to start. And again, that wire will not prevent the car from starting unless the big black battery cable is no good. Chances are if that's the case the little black wire will melt.
#9
As a matter of fact, my battery tender doesn't like this battery. I think the voltage is way to low for it even to crank. I took a multimeter to it and I believe it was reading in the 4s or 5s. Even if the problem is the battery, I'd still want to know where that wire goes. I cannot find the other end or terminal where it attached.
#13
Pull the battery and have it load tested. Id do the same for the alternator. Have it bench tested. That battery looks like the wrong "group" size for the car, Replace it with the correct "group" size and CCAs...at least 650-750 CCAs IMO...
Clean both sides of both the positive and negative cables. The negative battery cable should be attached to the engine behind the power steering pump with a shallow bolt and a star washer. There is a ground strap that connects the rear of the cylinder head to the firewall. Install one if its missing or ratty.
With a fresh battery and good cables and connections the car should start right up as long as the starter and solenoid are in good shape too.
Fusick, Year One and others offer OEM parts for your car. Dont go the big box places and try to find "will fit" grade zero parts & fasteners.
https://www.fusickautomotiveproducts.com/
https://www.yearone.com/Catalog/1964.72.cutlass.442
#14
That is an accessory ground there to get the front end of the machine in electrical balance a little more quickly than bouncing back through the block and alt case. Prevented flickering headlights. Will absolutely not prevent car from starting if not hooked up.
#17
Good news, but dont rest yet...A new battery will mask bad or not so good grounds and other tired components. In other words, the charging and starting system are still working harder than designed. Which will tax the new parts (battery in your case) and reduce life expectancy on the rest. Every 40-50+-year-old vehicle should have its grounds and + connections cleaned and sealed. ? Read your charging VDC. It should be 13.8 to 14.2 VCD ish. The voltage drop should not dip below 10.5-11.5 VDC...ish.
#18
Ok so from the battery, you connect the 2 wires from the negative terminal to the engine block (Thick wire) and to the frame (Thin wire). Does this thin wire allow you to connect other grounds to the frame? Or it has noting
#19
The negative big wire I think goes to the alternator housing, someone will confirm.
The little wire goes to the core support (black thing that holds the radiator and headlights. Move the wire around and look for a mysterious hole (or one with that bolt above) in reach of the wire for no good reason. This provides an additional ground path for the core support for the headlights.
Everything else is grounded to the body. There is a large braided ground strap somewhere from frame to engine, and probably one from body to frame. The fisher body manual and chassis service manual will have details. You should get those books for your year.
The little wire goes to the core support (black thing that holds the radiator and headlights. Move the wire around and look for a mysterious hole (or one with that bolt above) in reach of the wire for no good reason. This provides an additional ground path for the core support for the headlights.
Everything else is grounded to the body. There is a large braided ground strap somewhere from frame to engine, and probably one from body to frame. The fisher body manual and chassis service manual will have details. You should get those books for your year.
#21
The thin 10ga wire attaches, as we described, to the radiator core support. Look at the vertical driver's side metal support that the radiator sits in. The wire is the right length to reach it. At least that's where it attaches in a 68-69. The assembly manual for your car will show the correct location if I'm incorrect.
#22
Generally a black wire is on the negative post of the battery and bolts to the engine block. Be sure its metal to metal, remove any paint, grease, grime, etc where you put the ground. The Red goes to the horn relay on the drivers inner fender.
Its ok to put extra grounds. There is usually one on the firewall behind the motor that also bolts to the motor, usually a valve cover bolt or anything (clean) within reach. The heaver the wire the better. I also put one at the rear of the car, frame to body. My extra black off the battery terminal was/is on the drivers inner fender, i added another to the same screw to the radaitor core support. Cant have too many grounds.
Steve
Its ok to put extra grounds. There is usually one on the firewall behind the motor that also bolts to the motor, usually a valve cover bolt or anything (clean) within reach. The heaver the wire the better. I also put one at the rear of the car, frame to body. My extra black off the battery terminal was/is on the drivers inner fender, i added another to the same screw to the radaitor core support. Cant have too many grounds.
Steve
#23
The thin 10ga wire attaches, as we described, to the radiator core support. Look at the vertical driver's side metal support that the radiator sits in. The wire is the right length to reach it. At least that's where it attaches in a 68-69. The assembly manual for your car will show the correct location if I'm incorrect.
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