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TOPIC: Check and clean the Grounds!

Check and clean the Grounds! 10 Jul 2015 01:15 #1

  • Tracy Gallaway
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I had a funny and slightly embarassing incident a week ago. My cousin has a 1970 Chevy Malibu ragtop that I replaced the engine in 14-15 yrs ago. It lives in a garage and only comes out for summer drives, probably only about 1000 miles on the rebuilt engine. So my Cuz asked me to come over to see and fix a no-start condition.
IT had a fresh battery fully charged to about 12.7 volts. A new starter as well, but no sign of response with a turn of the key. So we hemmed and hawed over it, I checked the fuse box the fuses had corrosion and only showed a bit over 8 volts...? Even w/ a fully charged newer battery the car was electrically dead. :angry: The battery terminals looked perfect batt. cables were excellent too. No corrosion at all... Tried direct hot wiring the starter solonoid, still nothing. Thinking it was a bad starter or solonoid, we proceeded to spend several hours pulling the header and starter, then connecting the solonoid hot terminal direct and grounding the case- and click goes the solonoid!

Ok so we reinstall starter and header after I scrupulously cleaned the block metal for a good ground to the starter...and AGAIN nothing from the solonoid or starter. Then- I noticed a short thin stud at the front of the starter winding case. On a hunch I had my Cuz feed a 12 guage wire w/ alligator clips on it down to me. I clipped on to the thin stud and had Cuz ground the other end to batt. neg. terminal--and CLICK goes the starter solonoid!! :blink:

So- I removed the batt. neg cable from the battery terminal and cleaned it even though it looked fine. Re-connected it and it cranked and started! ;) I tell ya the battery posts and cables looked PERFECT, but there was enough oxidation on the neg. post and ground cable terminal to cause a 4 volt voltage drop! :blush:

So I got to learn about bad grounds and re-learned about voltage Drops all over again. Boy did we have a good laugh over this, and my cuz and wife fed me a real nice steak dinner for resuscitating the Cruiser! How to turn a 5 min. job into a full afternoon of wrenching!!

Dr Jacobs said in his book- "By 4 to 1 most electrical problems are caused by bad Grounds."

amen!

Tracy G
Tracy Gallaway
Carburetor Coach
Mood Elevator
Gadgetman Reno, NV

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Check and clean the Grounds! 15 Aug 2015 22:20 #2

  • Tracy Gallaway
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As we are jointly perusing the ongoing saga of Karl's Mazda--let me again re-emphasize the concept of cleaning wiring harness grounds, and computer-related wire/plug connections! :evil:

I've seen it, others certainly have, corrosion never sleeps. If you do any reading in service Manuals re: electrical or ECU diagnostics, you will see mentioned again and again: check the electrical connections!! Such small things, so easy to overlook, I think we humans want to look at something BIG we can see.

but just like a bee's stinger- such a small thing can cause a LOT of pain..or gnashing of teeth! I checked the Forum My topics button, Ive posted on 372 topics... :blush: (THAT many?) and this is one of the most Important IMHO.

Just sayin..

Tracy G
Tracy Gallaway
Carburetor Coach
Mood Elevator
Gadgetman Reno, NV

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