427 BB Positive battery cable routing

[Joe B.]

Need a little help on a 1966 427 L36. Does the positive battery cable run from the solenoid directly to the clip at the blower motor. And it does not use the clip on the battery heat shield? I cannot find the L36 routing in the AIM, just L72. I suppose they're the same and do not use the heat shield clip.

[Gary S.]

Re: 427 BB Positive battery cable routing

You can run the positive cable thru the solonoid clip but that clip is mostly to hold the starter wire harness coming down from the heater box clip. The heater box J-clip is only for the starter wire. A real 66/67 427 made car had a clip riveted on the firewall as shown in my picture to retain the positive battery cable away from the exhaust manifold and then was routed to the positive battery post. I think you will see this in the L36 AIM.

[Steve B.]

Re: 427 BB Positive battery cable routing

Great picture by Gary and to answer your question about the battery heat shield clip, it is not used on 67 big blocks.

[Joe B.]

Re: 427 BB Positive battery cable routing

Thank you Gary & Steve

[Greg W.]

Re: 427 BB Positive battery cable routing

Gary,
In the picture you showed the upper clip is part #3788712 and the lower clip is #3799990 both in the AIM. What is different about the two clips. I am replacing the rivets on my L36 and would like to use the correct one's if they are different. Thank's
Greg

[Richard M.]

Re: 427 BB Positive battery cable routing

Gary,
In the picture you showed the upper clip is part #3788712 and the lower clip is #3799990 both in the AIM. What is different about the two clips. I am replacing the rivets on my L36 and would like to use the correct one's if they are different. Thank's
Greg

Greg, Gary may confirm, but as I was researching the 3788712 clip for another post question, I came across this Thread...

See Post#11. It states the 3799990 was vinyl/plastic coated per the print.

https://www.forums.ncrs.org/showthread.php?92315-New-Forward-Wiring-Harness&highlight=3788712

I've observed that if the clips hold electrical wiring, it was vinyl coated(3799990). Clips for the hood cables were uncoated(3788712). However, it's possible that they occasionally got mixed on the assembly line.

[Greg W.]

Re: 427 BB Positive battery cable routing

Richard, The other post in question, I am the friend Don stated. The 3788712 clip for the spedo cable I can see not being dipped as it is a cable. But the same 3788712 clip is used at the bottom of the heater box to hold the wires going to the starter, (aim upc 12/A9 #22). It is in three places on that page. Any thoughts? Thanks for the help.
Greg

[Richard M.]

Re: 427 BB Positive battery cable routing

Richard, The other post in question, I am the friend Don stated. The 3788712 clip for the spedo cable I can see not being dipped as it is a cable. But the same 3788712 clip is used at the bottom of the heater box to hold the wires going to the starter, (aim upc 12/A9 #22). It is in three places on that page. Any thoughts? Thanks for the help.
Greg

Greg, In the research I did earlier, no one had a blueprint for the 3788712 clip. All I've encountered were not coated and bare steel or backed-out.

Here are my thoughts though.....

The 3788712 clips that hold the hood release cable up in the cowl area are only for the cable itself, not for any wiring. The wiring is attached to the cable using the plastic ties. The hood release cable is grounded via the underdash hood release cable-pull knob which is attached to the cluster housing, which is definitely grounded. This may be why the harness wiring was never intended to be captured by those clips directly and were isolated by the plastic ties.

All other clip locations are attached with rivets directly into the fiberglass, therefore those clips are never directly grounded. The clip on the lower heater box stud in the engine bay is not grounded. That heater box stud is isolated from ground as it's embedded in the box itself and never touches grounded metal.

But, for any clip that holds wiring in a un-coated clip, it could eventually chafe through the harness and cause a short, not to ground but to other wires in the harness. ANother example.... look at the bare backup lamp switch harness clip in the transmission tunnel. It's a bare clip too. However, if those wires shorted together to the bare clip, it wouldn't hurt anything, it would just flicker the backup lamps on and off going down the road. I'd bet this may have happened to a few cars.

For this reason some of these clip configurations make no sense. I think they thought of several potential wiring short scenarios to prevent, but not ALL of them. IMO all clips should have been coated when wiring was involved. But much of this may be related to cost. I'd imagine the coated clips cost more, and the engineers were probably trying to keep costs down to keep the finance folks happy.

Rich
PS Your reference thread ....

https://www.forums.ncrs.org/showthread.php?122624-66-67-AIM-hole-diameter-question

PPS Here is another thread that has more clip info, also particular the "mystery clip" we figured out behind the brake booster area and it's oddity.

https://www.forums.ncrs.org/showthread.php?116052-1967-L71-Engine-Bay-amp-Underdash-Wiring-Configuration-Views

[Greg W.]

Re: 427 BB Positive battery cable routing

Rich, Thanks for the help. I looked at my car and the clips for the hood cable and the clips on the fender are all bare. Some have wiring and some just the hood cable. None of these seem to have been off the car. I was missing the lower heater box clip that I will replace. There are two coated clips on the firewall, one has the back-up light wire in it,the other is just above the clutch pedal rod and holds some wireing. And the one is coated for the pos bat cable. Just a thought, could the bare clips have been installed in the body build area before paint and baking the paint. The coated clips down the line as not to burn the coating? Just a guess. Thanks again
Greg

[Richard M.]

Re: 427 BB Positive battery cable routing

Rich, Thanks for the help. I looked at my car and the clips for the hood cable and the clips on the fender are all bare. Some have wiring and some just the hood cable. None of these seem to have been off the car. I was missing the lower heater box clip that I will replace. There are two coated clips on the firewall, one has the back-up light wire in it,the other is just above the clutch pedal rod and holds some wireing. And the one is coated for the pos bat cable. Just a thought, could the bare clips have been installed in the body build area before paint and baking the paint. The coated clips down the line as not to burn the coating? Just a guess. Thanks again
Greg

Greg, I don't think baking would burn the coating.

Rich

[Greg W.]

Re: 427 BB Positive battery cable routing

Rich, Thanks for all your help, you are a asset to this group!
Greg

[Gary S.]

Re: 427 BB Positive battery cable routing

Regarding my post (#2), friend called. I should point out my picture is of a 67 427 car (St. Louis body) and all the pictures I have of 67's have the same clips and rivets for those two clips.

In 66 Smith and St. Louis made 427 cars. I own a Smith body 66 427 convertible (VIN #22300) that has those two clips but are held on with recessed head hex screws that look like the ones that hold the interior floor courtesy lights on. I don't have the AIM for 66 so not sure if the battery cable clip was used from day one or not in 66. Do your own research. I wanted to add this just to show there is a difference. Also, you will find the battery cable retainer clip was not attached in the same exact place on every car. Pictures attached of my 66 for your viewing pleasure....