Little bit of troubleshooting today

Help Support 7173Mustangs.com:

vintageman

VIP Members
Joined
Dec 10, 2017
Messages
506
Reaction score
101
Location
Georgia
My Car
1973 Mach 1 "Q Code"
So, I have been troubleshooting a possible battery problem with my 73. I am not trying to start it, just verify that I have things connected properly. I rebuilt the engine and have run it on a stand so I know that is good, sent the entire harness to Midlife, so I know that is good. I had to buy the engine gauge harness because my car did not have one when I bought it and I just changed out the the ignition switch and lock cylinder. I simply wanted to hear it crank but all it would do was an initial crank, and nothing after that.  The battery tested with good under load and had 12.53 volts. Did a multimeter check from battery post to post and had 12.53 volts but from cable to cable intermediate 2-3 volts. Checked all of my grounds and recleaned them to make sure they were good. Verified cable to cable, still intermediate with only 2-3 volts. Positive cable to ground had 12 volts. Damn, need to recheck ground again! Went from ground cable to end of ground cable, I had continuity, but no continuity from battery clamp to ground. I have the type of battery clamp that separates via two bolts and connect the battery cable between. Took that apart, wire brushed the excessive paint off that the manufacturer put between the two pieces and now I have continuity to ground, 12 volts from the cable test and the engine cranks as it should. Great time troubleshooting and very productive. I hope this helps someone, don't trust new parts and new battery clamps.

Tom

 

airfido

Well-known member
Joined
Dec 6, 2018
Messages
45
Reaction score
16
Location
Florida
My Car
1971 Boss 351 Tribute (H-code)
You mean like these?:
1642865568101.png
I have never liked them myself, for just the reason you state. They have failed me on more than one vehicle.

I have switched, with great success (so far), to premade like these:
1642865827899.png
Just gotta make sure the wire gauge and length are correct for your application (resistance). I have also had good luck with what I call the "marine" style with an eyelet lug crimped at both ends of the cable and attached to the terminal via a wing nut (or hex) like this:
1642866350494.png
Of course, it's only as good as the crimps, and the clean contact surfaces. Kinda ugly too, so...
 

Hemikiller

Tech Advisors
Staff member
Moderator
Joined
Jul 12, 2010
Messages
3,556
Reaction score
762
Location
Killingworth, CT
My Car
71 Mach 1
65 coupe
Your description is of "emergency repair" terminals, which are not intended for long term use. Get yourself a new *quality* set of cables from NAPA if you want good aftermarket, or order from NPD for factory style. The aftermarket style will have a small ground strap coming off the battery lug, be sure secure it to your fender apron. The factory ground cable had a strap mid-way the screwed down under the lower voltage regulator screw. Many miss that and don't replace it, or buy the wrong aftermarket cables that don't have it. Make a quick and dirty ground strap from the battery terminal to the screw on the starter solenoid and see if that solves your issues.

71ground.jpg
 

cv_72mustang

VIP Members
Joined
Apr 14, 2019
Messages
206
Reaction score
41
Location
PA
My Car
72 Vert 351C White
I've used these and they work great. Machine crimps !!
 
Top