Hello.......I'm a little green to this, so any help would be much appreciated. I have had my '79 F150 with a six cylinder for about a year. I just bought a new battery for the winter. I want to make sure the cables that are installed are the correct ones and if all are necessary. There are THREE cables connected to the Negative clamp! Here's the set up:

1 Positive cable - Battery clamp to Solenoid (Marked 6 GA.)
1 Positive cable - Solenoid to Alternator (.200 in diameter)
1 Positive cable - Solenoid to rear of Starter (.300 in diameter)

1 Negative cable - Battery clamp to Battery tray mounting bolt (.270 in diameter)
1 Negative cable - Battery clamp to Starter mounting bolt (.350 in diameter. Marked "4221 NEG" on cable.)
1 Negative cable - Battery clamp to Engine block (.375 in diameter)

Is the negative cable running from the clamp to the Starter mounting bolt necessary? I just thought you needed one ground to the engine and one to the body. The clamp can barely fit a few strands from the third negative cable. Are the cable sizes correct? I have a feeling they are not. I apologize, but I do not know my gauge sizes yet. I'm fresh. Thank you kindly.

 

No you do not need the one from the starter bolt to the clamp. Having a large gauge ground to the truck frame and one to the block of the motor would/should be fine. Large gauge like 8 or 10 gauge would be perfect. Run new ones yourself, it's not hard and you can pick up everything at the local parts store.

 

Three? Thats' overkill. Battery neg to engine is fine.

But chassis grounds are a good thing because weak grounds can cause electrical gremlins. I recommend ground straps as follows: engine to cab, cab to frame, and bed to frame.

Interestingly, my 70 has a ground strap under a front bumper's nut to the right frame horn and I've seen a few others in the JY with the same thing. Weird.

 

Now that REALLY sounds ghetto. You don't have a picture of that do you? I love seeing people's farcical repairs/additions. ( I know it wasn't you )

 

Thank you for the replies! I thought it was overkill as well. I would have taken a photo, but my camera died last week. I plan to post more stuff about this truck in the coming months. I bought it from a guy that used a crescent wrench for almost everything, so this should be fun. Thanks again!

 

Ahh! "crescent wrench guy", i believe he's related to "duct tape guy", don't ya just love PO's.

 

Quite often the WORST thing that could happen to our trucks is a "previous owner".

 

Not factory but you should have a three grounds from the battery. One to the block, one to the frame, and one to the radiator support. Then A ground from the cab to the frame, and the bed to the frame.

 

So so true! Thought it many times; just never saw it in type.... This could be a separate thread, "Whats the worst you've found/seen" My latest is the "po" used bolts to cap off the air tubes on a 360ci. Only thing is that he left them tall enough to interfere with the valve covers.... The covers couldn't seat and there is a 1/2in of buildup everywhere from years of oil leakage!

Checking and cleaning existing grounds can cure "electrical gremlins" also. Thanks for the reminder!
.

 

Is there not a PO here amongst us, let the finger pointing commence, i plead innocence.

 

This is the first time I have ever heard about a ground to the radiator support. Why is that important and what gauge wires should I install for each ground? What kind of battery clamps do you guys recommend ? I'm looking to buy good quality. I think the "duct tape guy" and the "crescent wrench guy" are brothers!

 

There is a thread on this very subject, I can't remember the title though. Some of it is hilarious and some of it all you can do is shake your head and wonder WTF?

 

Here they are:

From the dentside forum:
https://www.ford-trucks.com/forums/9...se-owners.html

From the bullnose forum: https://www.ford-trucks.com/forums/3...r-post-up.html

 

One cable from battery to block. Block to firewall, block to frame. The only reason I know of to ground radiator, is if using aluminum radiator that is shock mounted(isolated). "Supposed" to help with corrosion due the different metals involved. Won't even get started on PO "modifications".

 

I have one to the radiator support since before I did the 3G alternator upgrade that was where the regulator is. Having a ground there cured my dimming headlights. Now I have my dc control fan control in that spot and that is a super high amp draw. I just wanted to make damn sure there werent any issues in that area.