I took apart my LG4 Z28 a while ago and am currently trying to get all the wiring back together. The only thing I cannot figure out is what grounds go where, and whether or not I'm missing any straps. Can anybody tell me what grounding locations come out of the harnesses and what they connect to? Also, where I need ground straps?

I did google this and search on here, but I didn't find anything that really answered my questions.


Also, I'm not sure if this is related or not, but I cannot get the engine to crank over. I hooked up a battery to it and it just clicks and wont turn. Tried jumping it and still nothing. What's going on there???
Thanks!

 

You could dig out the service manuals and look at all the illustrations, but the beauty of ground wires is that for the most part, they can go to any common ground.

Without having laid hands on an LG4 since about 2003, I can only take an educated guess, but you should have a wad of ground wires to the back of one of the heads. And you should have a braided ground strap from the back of one head or the other to the firewall.

 

Thanks, that at least gives me a direction to go.

 

grounds from the ECM harness go to the rear of the passenger head, as does the ground strap from the head to the firewall. each set of head lights is grounded to the body near the rad support. there are others as well. post if you come across one that you can't figure out.

 

Thank you so much that makes it a lot clearer.


Any idea if this will clear up the cranking issue?

 

I have a few pictures taken with a crappy digital camera from my 84 TA showing the grounds at the back of the heads. But I have to post from a different computer. I will do it ASAP for you.

 

While you're fiddling with grounds do yourself a favor and ground the passenger side head and block together and then ground the block to one of the inner frame rails. Iirc that ground strap to the firewall may be the only thing grounding the engine. Great source for inexpensive pre made grounding cables are the pre wired lengths at Walmart. They're cheap, come in varying lengths and have the ends on. My local store usually has 8/6/4 gauge.

 

I looked, no pictures, but my notes say (3) grounds on the back of PASS cylinder head under a 3/8" bolt.
And I believe Tibo is correct about the grounds. Make sure you have a proper ground to the block, frame and body - even if the factory didn't put them there.

 

Thanks everyone I will just make sure everything is grounded and bonded together.

 

If anybody has pictures that would help a lot. I have a ground connection with 2 black wires coming out of the harness closer to the alternator. Where would that go?? And how would I go about Bonding the block and heads together? Where would I attach them?

 

Just to get running, a ground is a ground just as long it is grounded! All black, black w/ white trace and tan gounded. Ground to block to frame and fender support/radiator support. Get it running then get in the right location.
JOE

 

 

Sounds like a bad batt or batt cable. Assuming of course, that the black batt cable is where it needs to be: as close to the block, electrically, as it can get. NOT to the "frame", NOT to the chassis, NOT NOT NOT NOT NOT NOT NOT. To the BLOCK or as close as possible, such as a big fat bracket that's bolted to the BLOCK.

Once you get that settled, if it still has trouble, use your DMM to see where the voltage is going away.

 

I bought a new battery and everything works great. I'm so glad I finally got it all settled.

Now I can move forward with my project.