How many grounding straps do I need on my 70 Cutlass and where should they be located?

 

Not including ancillary equipment: (1) NEG (=) BAT terminal post to engine block; (2) NEG (-) BAT terminal post to upright chassis fan shroud side support; and, (3) rear of engine head to firewall.

 

 

Norm is correct. The only reasons you would have to run additional grounding would be if you have a "system" with amp and auxiliary speakers, a CB/ham radio, or aftermarket EFI.

 

Referencing my statement regarding ancillary equipment, there are additional ground strap locations for the fuel tank (ground), dash/instrument panel (ground), steering column (ground), etc. Ground locations can be found in the Product Information Manual (PIM).

 

And if a rear-mounted battery is frame-grounded, add a full-size cable grounding the engine block to the frame.

 

Just wondering if there is a ground that should go between the body and frame?

 

The ones mentioned by Norm above are the only ones you need. Why do you want to add a strap between the body & frame?

 

If you put your battery in the trunk, a ground strap to frame is seriously recommended.
But the Neg to the engine block is essentially a ground to the frame.

 

The reason I am asking is that I am having trouble with my right brake lights intermittently not working so, I think it is a ground issue. The left brake lights work fine. Since the lights do not have a ground wire then its grounded thru the tail light assembly then thru the bumper then thru the bumper brackets then the frame. The next thing I am going to check is to make sure the tail light assembly has a good contact to the bumper.

 

You're correct in looking at the tail light assembly. Many require bulb replacement socket &/or wiring assemblies.

 

I have had this intermittent issue for quite sometime and even after I did some tail light maintenance back in December I am still having the same problem. See link below to my post about it. So, I am gonna make sure the tail light assembly is making good contact to the bumper and then the next step would be checking the wiring. Gotta love those intermittent electrical issues!

https://classicoldsmobile.com/forums...-issue-189697/

 

I've replaced many tail lamp socket assemblies on many classic vehicles. There are many tail lamp sockets & socket assemblies available from variance manufacturers. As you stated in your other thread & as I have witnessed anything w/in the wiring &/or assembly is suspect, springs, corrosion (likely suspect) at any point (often the socket itself becomes corroded & creates intermittent contact). You may stab the wire(s) one day w/ a circuit tester to find you get a good closed circuit only to find the next day you perform the same test to find a bad (open) circuit.

In general, I cut the wires & replace the entire socket assembly splicing into the remaining harness wiring. Most times (and the last time) I walk into a general auto parts store, reviewed their socket assemblies & picked one out. Don't be dispelled if they don't look "identical", most of the aftermarket tail lamp socket assemblies fit MANY of the classic cars (at least those which utilize 1157 bulbs). The crimps which hold the socket assembly often challenge individuals, but w/ a slight>modest amount of ingenuity you can easily remove (cut/rip out) the current socket assembly and install a new socket assembly. A little ingenuity is really all that's required. Depending on where you're looking for replacement socket assemblies (on-line vs. in-store) I suggest you stop by several local auto parts stores in your area & merely look at what they have available right off the shelf. Maybe you've already done this? At any rate, many types are available.

 

Hello Norm,
Yes, I have explored replacing the sockets but the way the factory makes them (crimping the copper socket onto the tail light assembly) is far superior than what the auto parts stores sells. My sockets/springs are in good shape. A good clue for my troubleshooting is the left side tail lights work all the time. The right side is giving me the trouble and as you know there are two bulbs per tail light assembly in the 1970 models. Both bulbs on the right side are both intermittently working which leads me to it being a ground issue.

 

Kevin - I agree w/ you, the most likely suspect is a simple ground (-) side issue.

 

RE: Crimping. I completely understand. It's exactly that crimping which often times looks unapproachable w/ aftermarket sockets when you evaluate the "crimping". I've replaced several sockets with aftermarket sockets which are not "identical" but are very well made. They may have fewer or more "crimps", or the size is a little bit cattywampus, but it's what I was attempting to indicate previously, with a little ingenuity you can install several of the aftermarket sockets after you cut out/remove the OEM socket(s). A little ingenuity is all that's needed and you'll get the "crimp" to provide a secure ground connection. At any rate, best of luck - you got this.

 

I got tired of fighting the ground issues on my taillights. I modified my taillight housing to accept a socket with a ground wire, and ran the ground wire someplace more weather resistant. It’s been 20 years, zero problems since.

 

Matt - Agree. Many have gone that route - often times in necessity &/or for simplicity.

 

If you put in LED bulbs that may be the issue, those tabs on the bulb are a little shorter than the originals, I have a problem on one side every now and again.