It's official....I'm an idiot!

[TxAgs66]

Ok everyone, gotta tell you this story.

So, most of you know that I have been struggling with electrical gremlins as well as throttle surging. Well, I think I finally figured out the problem.

Turns out that not only does the engine need to be grounded, but the chassis does also! After I ran a new chassis ground to the battery, all of the issues went away, including the acceleration surging.

Here's the interesting part. My car never had a chassis ground in the first place. What happened is that over the past few years, I have replaced the engine, tranny and suspension, effectively isolating the engine from the chassis/electrical system. The electrical problems all started after I put in the T5 with new mounts.

So, interesting lesson learned! Now its time to worry about something else. Time to think about getting a paint job and ordering a head.

By the way, it all dawned on me when I was claiming that I had great chassis ground. Then I realized it was from the engine to the battery.

Jason

 

[rbohm]

8) dont fell bad jason, i was trying to track down an eletrical problem with my old F250. the gauges read normal until i turned on the headlights, the the temp gauge started climbing. it took me a while to realize that there was no ground between the engine and the chassis, except through my temperature gauge. once i ran a ground from the batteries to the chassis, my problem went away.

 

[ludwig]

That grounding is not a simpleton's art. There are a couple of obvious grounding points but there are other less obvious ones as well. There is a ground strap or wire from the starter motor to the firewall. There is the battery to the block and then there are a couple of passive grounds. The motor mounts don't do it because of the insulators.

Furthermore, what was once a ground can lose continuity over time by the buildup of contaminants or paint or rust. What once was a metal to metal contact with a bolt through the middle slowly becomes an insulator with an insulating shank in it through oxidation. When you reinstall stuff, you have to dress off the contacts with fine grit paper or a brush or something to get good metal to metal contact.

 

[Thad]

And you're an Aggie too.

Electrical grounding is often a hidden problem because we do think/ know about it and it is not on any check list.

 

[Frankenstang]

And you're an Aggie too.

My dad was an aggie too...rest his soul, so I use to know a ton of these, but this was always one of my favorites...

An aggie and an irishman from ND come upon a dog curled up far enough to do some cleaning on the family jewels.
irishman: "WOW!...I wish I could do that"
aggie: "Yeah, me too!...but I'd bet he'd bite ya.


Seriously, I'm about to install a new ground strap as well...from the firewall to the block where my batt ground connects (a sufficient overkill batt style strap (4ga?). I don't know when mine was deleted, and I'm really surprised I don't have more issues than a dancing amp gauge at this time. However, I'm also considering running an 8ga length from the firewall connection back to the trunk area where a smallish amp and smaller sub are located...just not sure if I should dead end the ground to a sheetmetal point in the trunk or hook up an actual 'ground block'
I'm definitely subscribing to the thought there's no such thing as too much ground.

 

[66 Fastback]

I had bought and assembly manual for my Pontiac and found that I was missing several of the stock grounding straps. A couple from the Firewall to the engine heads and another from the body to the frame. Things like those straps disappear over the years as the cars are molested.
Nothing wrong with being an Aggie! Too bad the Men's B-Ball did not beat Kansas last night.
Doug

 

[Funky Cricket]

I had some odd issues resulting from a bad chassis ground as well. I figured it out pretty quick, but was a bitch to troubleshoot.

 

[TxAgs66]

Thanks for the support guys. The Aggie comes out in me at the worst times!

Now on to bigger and better things, like a paint job.....

 

[Bradbutlernc]

I upgraded all my wiring to 4 gauge, only cost about 25 bucks for wire, ring terminals, and new battery terminals. I noticed a difference in how the car cranked and the brightness of the lights too. I had a ground to the battery, ground to the starter motor, and a ground from the starter motor to the chassis that i replaced ,stock. I had to add a ground from the engine block to the frame under the engine, not sure if that helps or not but i dont have any electrical issues. Its well worth the upgrade, you shouldve seen how bad the stock wires were, terrible.