We often have discussions regarding the location of ground straps and the fact they can often cause electrical failure when not attached or not securely attached. Below is a run-down of the ground straps used. This post will be updated with additional pictures and info in the future and will be added to the Help Topics page.
Negative Battery Cable
These originally came with spring ring terminal type cables, but have often been replaced with bolt terminal cables over the years. Either type is fine, however, you need a clean tight metal to metal connection as with all ground connections!
Below is a picture of a original type spring ring terminal negative battery cable.
Below is a picture showing an original type spring ring negative cable with the short braided harness that attaches to radiator support:
Negative Battery Cable to Frame and Radiator Support
Battery cable negative to frame and short braided harness from bottom of battery cable to radiator support..where you have lots of electronics attached to or feeding through. I often see newer bolt terminal cables installed on these cars with no ground back to the radiator support and wonder if that degrades the current flow.
Picture below shows the bottom of the negative cable connected to the frame; the short braided ground strap attached to radiator support. You can also see in this picture the right/passenger side forward lamp harness small ground wire attached to the frame all in that same picture. That's 3 grounds in one area.
Right Frame Rail to Engine:
Very large heavy gauge ground strap from right frame rail just underneath the firewall cowl area, over to engine block at transmission. This is the main culprit for ground related starting problems. Here is a picture mounted on the frame which is just above the front transmission cross-member location:
Forward Lamp Harness to Frame
just in front of the radiator support on both left and right side (will cause headlights to not work. See picture above for example of Right side and the picture below of Left Side which is just beside the VIN # stamped on front frame rail:
Left and Right Cylinder Head to Firewall/Cowl Ground Straps
One ground strap from back of each cylinder head to firewall/cowl.
See pictures below:
RIGHT SIDE CYLINDER HEAD TO FIREWALL:
LEFT SIDE CYLINDER HEAD TO FIREWALL:
Grounds to radiator support at voltage regulator
Control Arm Ground Strap - Shaft to Control Arm - On Left and Right at Rear
Several Other Smaller Ground Straps
There are many other grounds throughout the car such as the AC compressor to water outlet pipe cover bolt, wiper motor to attaching bolt, power seat motor to seat rail, fuel sending unit to frame, etc. Also the relays such as horn, seat/window (on 64), etc generally complete the "control/feed" circuit by way of ground to the body somewhere.
Awesome Jason! Thanks for the info...
Thanks, Todd. I just added 5 new pictures, 4 from the current parts car, showing additional ground strap locations. The forward lamp harness and cylinder head to firewall show a lot of corrosion built up over 50+ years and one reason why these need to be inspected, cleaned, and reinstalled to make sure you have solid metal to metal contact.
The ground strap is attached to the flywheel housing --just in front of the starter --where the starter bolts into it --on one side of the ground strap
The other side of the strap --is bolted to the the right side of the frame rail
It is a bit of a difficult picture to take when you get one side of the strap you cannot see the other side of it from the photos of that strap i have viewed
Another ground you would want to be very clean --is the ground on the regulator to help keep the charging system working reliably
Does anyone know where to buy the replacement straps for the "Control Arm Ground Strap - Shaft to Control Arm - On Left and Right at Rear"
Lectric Limited and OPGI (who sells Lectric Limited) only sell replacements for the three major straps: engine to frame and both engine to firewall straps.
Also accepting advance on gauge choice if homemade :)
Thank you in advance,
I have them very good used for $10 each. Email me at email@example.com