The ground wire is also attached to the frame near the motor mount. It appears to have the insulation removed and a clamp swaged onto the bare wire. The clamp also has an addition insulated clamp for the positive wire for the starter.

I feel it is important to have the battery ground cable attached to the starter as the starter draws over 200 amps. Putting the battery ground near the ALT would mean the current flow would have to travel through the engine. It is like using a DC Arc Welder; you always clamp the ground lead to your work, not the bottom of the metal bench leg.

Also shown are two pictures of an engine ground wire. It connects near the oil pressure sender and attaches to the lower inboard wiper motor attach bolt. This grounds the engine to the frame/chassis. This ground wire has to be able to carry the return current of the ALT, so if you have an 100 amp ALT at full output it will need to be able to handle that amount of amps.

Personal I would add more engine grounds. A simple way is at the motor mounts, just jumper around the rubber mount. I would do this at each mount. Bad grounds can cause lots of problems that are often difficult to trouble shoot and solve.

As Festus Hagen said, proper grounding is extremely important and this can’t be over stressed.

 

thanks, Jim. Appreciate all the help

 

I'm pretty **** with grounds, intake to head to block to chassis for each head, block to cab, block to starter, chassis to bed, with bradded ground straps. I also run a wire from the alternator to block.

I ground my batteries to the block.

-Enjoy
fh : )_~

 

DK if I will start a thread on this, but, I have no current to the cab. Batt is good. Main suspect: large gauge YELLOW wire comes from starter solenoid and goes into firewall, passenger side. a large yellow wire comes out of firewall on drivers side, and is disconnected from a connector. with any luck that wire just goes to ground. any ideas?

 

other side of that connecter is gone BTW

 

I had a friend that couldn't get anything to work on a truck she just bought. Turned out every single ground was cut. Body to frame, engine to body, engine to battery, headlight grounds, horn grounds, almost seemed intentional.

I've had vehicles with grounds on the starter, altenator bracket, head, intake, and the side of the block. Didn't seem to matter they all worked wherever it was attached.

Your engine is pretty clean, at least you can see the starter. Hopefully it's just that ground issue.

 

see, i just took out the 86 eng, and put in a 81 eng. used the duraspark out of the 81. i SHOULD be able to get her to crank, at least. that big yellow wire is my prime suspect

 

Hey greyghost,that yellow wire is probably not a ground.It being yellow,I would suspect hot off the relay on the inner fender.Turn on something that isn't working,domelight maybe?,and run a jumper wire over and momentarily touch it to + battery and see if it comes on,don't hold it,just flash it until you see what it does.Don't be charging the battery will you do this!!!! Could go BOOM!.

 

buster, what would that show me, other than that my dome light was working? dont have the belt on the alt (so no boom), eng should STILL start, right?

 

You said you had no power to the cab.Do you have a test light? You could see if you have power when you turn the key on,at the coil,and at the small wire on the starter relay that activates the starter switch in the relay.I will check my manual and see if your truck diagram is in it,maybe I can figure out what that yellow wire is.I'm not great at tracing,I can wire almost anything,but tracing drives me nuts.I mentioned the boom because,as you probably know,when the battery is charging on a charger,it produces hydrogen gas and a spark is not good,if you have ever seen one blow.

 

According to the Haynes manual '84-'86 diagram,there is a yellow wire comes out on driver side that goes to the EEC Relay.I don't think you can get anything going without the EEC getting power.I believe that's the power to the brain,computer.I know on my '91 there was 2 or 3 relays together on that side,one was the fuel pump relay and one was the EEC relay,can't think of the other one right now,doesn't matter.I think that the EEC is pretty major,may shut everything down if it loses power,even the fuel pumps.hope this sheds some light on it for you.It shouldn't have been unhooked?

 

i made a test lite out of a tail lite socket and bulb. on the starter relay, where do i touch my wires?

 

There should be a small post that has a small wire coming from the key/starter switch,it should only have power when someone hits the starter with the key,this activates the relay to power up the starter.Ground 1 wire on your light and put the other on the small post.You can use that light to run through checking different places to find out what's hot and what's not,and you will find out where power ends.You can use it to see if you even have power to the key switch.That yellow wire makes me wonder,because I don't know if the EEC is critical to your truck,or maybe it's converted to not use the EEC.maybe someone else on here can cover it better that has modified their truck.

 

I had that large wire too. It terminates at nothing, and was covered with old crud. It appears to be unused unless you have the EEC. Is this a new truck? Has this run before for you? You might want to check the fusible links. I had this problem after I did my 3g upgrade. I disconnected the original alternator harness and had no power. I had to plug it back in and tape off the ends I did not use to get power back to the cab. I still do not understand it, but that is how Ford wired it.

 

what do you mean, ck the fusable links?