Low voltage - what else can I check?

[70 Oldsman]

Chase things as far as you can before spending $.
Got a harbor frieght close? If not, pay the shipping.
http://m.harborfreight.com/digital-clamp-meter-96308.html

How to circuit.
http://troubleshootmyvehicle.com/gm/4.3L-5.0L-5.7L/fuel-pump-circuit-tests-1

Ok progress! It's running now between 13v and 14v took it up and down the road and everything held. Seems to drop and 12v when I turned it off started it several times back to back. The speed monitor jumped when turning key on just for a second.

 

[70 Oldsman]

Ok progress! It's running now between 13v and 14v took it up and down the road and everything held. Seems to drop and 12v when I turned it off started it several times back to back. The speed monitor jumped when turning key on just for a second.

I believe that it turned out to be partially a ground issue. I made a ground from negative side of battery to finder. So my thinking is a ground that I checked may actually be bad.

 

[Sixfivedeesl]

Had the same issue recently. I hit a deer and blew my fog lights that I had located in my bumper holes. After that my needles on guages were whacky. Low oil pressure. Low voltage. Hard starting. Headlights would go dim. Found that my ground wire from passenger battery to fender had cooked itself and was broke in half barely making contact

 

[WarWagon]

Had the same issue recently. I hit a deer and blew my fog lights that I had located in my bumper holes. After that my needles on guages were whacky. Low oil pressure. Low voltage. Hard starting. Headlights would go dim. Found that my ground wire from passenger battery to fender had cooked itself and was broke in half barely making contact

Get rid of the ground loop! The battery is for starting the engine only and thereafter is a 6+ amp load for charging. Connecting grounds to the battery means when (not if) the main cable to the engine goes bad or high resistance the current will find other ways to get to the starter. This be through a fender ground, back through bearings, to reach the engine. As you found this condition will burn off the smaller fender ground.

You only want a ground strap from the engine to the frame and engine to the body(fender). Leave the battery out of (extra grounds) aside from it's heavy cables. Again the ground straps are heavy battery sized wires to do any good.

 

[Sixfivedeesl]

I think you mis understood. I didn't have my fog lamps grounded to battery. It is just them getting blown up from a deer which lead me to discover broken / cooked fender to batt ground

 

[WarWagon]

I think you mis understood. I didn't have my fog lamps grounded to battery. It is just them getting blown up from a deer which lead me to discover broken / cooked fender to batt ground

I forget these fender to battery ground loops are a "stock" mistake from GM. (I wrongly assume some ground everything to the battery instead of the engine.) I outlined how they 'cook off' when the main ground from the battery to the engine gets corrosion or otherwise fails. GM does wiring as cheep as possible including being undersized to the point of fires. Regardless a ground strap from the engine to frame and engine to body is always a good thing to add. You might look at the battery ground cables for corrosion. I have removed the battery to body ground wires on my vehicles and depend on the ground straps instead.

 

[jrsavoie]

I seem to have many fewer issues with my ground loops intact. They certainly have never caused me an issue. As long as your main cables are good, the ground lops just supply extra routes to places the grounds are already going anyway.
I ground right to the battery box instead of the cheesy ground to the fender- I've had sevral issues with that little screw over the years

 

[79jasper]

Who let the spam bot in? Lol

Sent from my SM-G892A using Tapatalk

 

[BoostN]

Got em'

 

[Will L.]

Got em'

Quick draw delete button! I didn’t even see it!

 

[NVW]

x2