New C30 rollback;wiring question

[KIILew]

You're about to learn just how uninitiated I am...

I am finally starting to play with my recent ’78 C30 flatbed purchase…and I have some electrical gremlins to solve. Maybe someone here can help me as I start in. Without jumping in to the myriad of electrical issues, here are a few initial issues and questions…

At some point, a previous owner installed top mount battery cables, with a 2-wire setup connected to the positive terminal. It appears that the second and smaller of these two wires (which appears to be a 10 gauge or so) supplies power to the fuse block. Moreover, it is clear to me that some previous owner installed this wire himself, and perhaps used this to replace wiring that would otherwise source electrical power from a stud on the starter solenoid (according to the factory wiring diagrams I have seen). I am afraid that the installer might have even removed the fusible link which I think should be present somewhere in the circuit. Tomorrow I intend to see if this wire terminates at the 2-stud junction block located on the firewall. This isn’t obvious without running some sort of continuity test as the wire in question disappears into a conduit buried between the firewall and distributor containing several other similar red wires (at least one of which is fastened to one of the two junction studs).

Does anyone have any thoughts regarding where the fuse box would best receive its power; i.e. when I replace this wire (which has cracked insulation, etc.) should I retain the direct install to the battery post, or should I reposition it to the starter solenoid? At any rate, I intend to make sure that a fusible link is in place, whatever I do.

In anticipation of this project, I purchased a 14 gauge fusible link at Autozone, which is packaged with a crimp connector. I am thinking that I will probably discard the provided connector and solder the connections instead. Any ideas on the advisability of connecting wires one way or the other?

Just thought I would ask.

Ken Lewis

[rfmaster]

Lew

The two wire mod actually solves a lot of problems - If it was done right. Yes, there should be a 6" fuse link 14 Gauge to protect against masive electrical fire. I placed my fuse link in the circuit just before battery.
The two stud terminal block is stock. In original factory harness had a 16 gauge fuse link right near terminal block.

//RF

[KIILew]

RF:

Thanks for the reply and thoughts! I haven't had the time to do anything about the wiring in the last few days since the post, but I am thinking that the direct-wire-to-the-battery setup (i.e. the "two wire mod") probably is more reliable than the original to-the-starter-solonoid installation. After all, that way the wire is kept away from hot exhaust system parts, road debris, etc.

I assume that the typical parts-store new positive battery terminal cables that are available with an extra 14 gauge pigtail for this purpose will serve as an adequate fusible link...any confirmations or disagreements?

Ken Lewis

[rfmaster]

Lew

Nope!!!! Fuselink is designed to start melting at known current (I have to look it up). 14 Gauge Cu wire pig tail will require much higher current to melt!. A good auto store will carry 16, 14 and probably 12 Gauge fuse link wire. Use about 6 iches with usual crimps - blue for 16 & 14 and yellow with 12 Gauge.

//RF Marry Xmas

[KIILew]

RF...

Thank you for the followup! I was starting to come around to that thought, and will use the GM fusible link wire (made especially for that purpose).

It is interesting to that you mention using the standard crimps. In the last several days of this posting exercise, I have done a lot of "googling" on this site and on the internet in general concerning the topic of soldering vs. crimping. Prior to this exercise, I always figured that the pro-solder crowd was right about crimping being inferior in terms of electrical conductivity and connection durability (although I have usually resorted to crimping out of expediency in the past). However, my recent info searches have revealed some seemingly thoughtful commentary about "properly" crimped connections being superior to "properly" soldered connections in vibration prone environments. Reasons cited include the notion that soldered connections are rigid and brittle and will eventually fracture if subjected to repeated motion.

So I am now gravitating back to the crimp method and covering the work with heat shrink tubing, and calling it good. Any further considerations?

"Lew"

[rfmaster]

Lew

I am electrical - electronic engineer with couple decades of experience. In my view a junction of two wires will always be a weak link in circuit.
A solder junction provides lowest possible resistance junction provided that both wire ends were properly prepped and physically attached. A good wire junction can be formed using ‘Western Union’ twist method. There are others, but this is my favorite and it is easy to form. However, most people do not know how to (properly) solder and this typically results in cold solder joints and / or oxidized wires. Also, solder joints are known to fail due to repeated heating and cooling. This happens in high current circuits were even fraction of ohm resistance may cause in substantial junction heating. Over time such joint will fail due to micro cracks in a solder which will further increase junction resistance. I have seen my share of high current supplies with blown PCB traces due to cold solder joints at the I/O connectors.
A crimp joint is well suited for automotive environment provided that it is properly formed and protected. The weakest link in forming a good crimp junction is a crimping tool. Most people purchase a $19.95 crimper from usual places – I should not name them. A cheap crimper will not properly collapse junction tube – resulting in a poor mechanical wire retention and highly resistive wire junction. I have tossed a few of them in the junk bin over the years. A professional quality crimper costs more than most people are willing to spend for a tool – we are talking hundreds of bucks.
Enough said – get the best quality crimper (Amp, Amphenol and the like) and heat shrink the junction to keep moisture, oils and junk from contaminating and degrading it.

Good luck
//RF

[KIILew]

RF...

Wow! Thank you for revealing that background and providing those insights!

Actually, several hours ago, on Google, I typed "solder vs crimp" and read numerous amazingly passionate message-board exchanges on the subject between proponents of both schools of thought! Just from reading those exchanges, I decided that it would be worth spending the money to buy a "ratcheting" type of crimping tool, or something like you suggest.

Your latest post really seems to objectively spell it all out! Very reassuring!

Already, I can see already that finding such a piece of equipment quickly is not going to be easy. I just got home from visiting a local industrial supply store looking for a ratchet type crimper and they didn't have a clue as to what I was talking about. They just sell the usual plier-type crimper.

Maybe I can locate one of the brands you mention on-line. Some of the stuff I have been reading suggests that marine quality connectors and heat shrink tubing with some special sealant incorporated is available and might be worth looking into too.

Any other recommendations, RF?

[rfmaster]

Lew

Well, now you know....
I can personally recommend the following two crimping tools – I used them both with very good results:
1) Amp (Tyco) PRO–CRIMPER Hand Crimping Tool 58433–3. You can find information here http://search.tycoelectronics.com/electronics/

2) Panduit CT-1550 hand crimping tool. You can find information here: http://www.panduit.com/products/Prod...ins/069169.pdf

Both tools are ratchet style, heavy duty industrial usage and will last a life time of crimping given proper care.

I use Amp PLASTI-GRIP Ring and Spade Tongue Terminals which are readily available from electronics supply houses. Most auto-hardware stores carry cheap Taiwanese or Chinese knock offs. They tend to have poor insulator quality and should be avoided.

Enough said – you may get more suggestions and recommendations to confuse daylights out of you!! Marry XMAS and Happy New Year.

[KIILew]

RF:

Sorry to resurrect an old topic, but just wanted to let you know that I am expecting to receive a Tyco Pro-Crimper III in the mail any day now. I did purchase the 58433-3 with an additional die set to handle non-insulated crimps, too.

Thanks again for the web sites and advice!

Happy new year!

Ken Lewis

[rfmaster]

Hey Lew

Happy new Year.

Enjoy quality tools and stay away from Chinese made garbage. My knuckles have many scuffs from poorly made tools - broken sockets, busted and undersized handles, poor grip material - the list is long.

On crimping - practice on scrap wire until you dial in the tool! If my my memory serves me right there are jaw travel adjustments. Test wire retention by performing a pull test. I use my fishing reel drag tester to verify crimp retention!. Remember if you change connector supplier - you may want to re verify crimp quality and wire retention.

//RFmaster