Chevrolet Intermittent Electrical Problem

This page is about the Chevrolet intermittent electrical problem. However, the issue also occurs on aging GMC and Cadillac trucks.

My Chevy truck customers complained about this electrical issue for years. Unfortunately, when they show up at the shop everything worked properly.

It’s difficult to fix a truck that isn’t broken. Intermittent electrical problems remain some of the worst issues to solve for even the most experienced technicians.

Quick Links: New negative battery cable for GM trucks. New Positive battery cable for Chevy Silverado. Aftermarket Starter solenoid battery cable.

With that said, enough people have had the issue, the problem finally got solved. The affected customers complain about intermittent power outages throughout the vehicle.

In addition, they can experience false check engine light codes and erroneous warnings on the driver information center.

Often the door lock actuators buzz and the power door locks operate on their own. Sometimes the dash lights go out or the entire truck loses power.

With that said, when the truck starts having intermittent starting problems it's time to do something about it.

Whenever crazy things happen like the above mentioned events, my mind starts thinking about ground connection problems. If symptoms become widespread and randomized poor electrical connections become primary suspects.

Chevrolet Ground Cable ConnectionChevrolet Ground Cable Connection

Intermittent ground connections can cause some really strange side effects. In this situation we often see a failure of the main ground cable that runs from the battery to the engine block and also to the frame.

I have personally seen several issues with this one ground cable in many make and model General Motors products built in 2000 through 2015.

However, the vehicle that brought me a successful diagnosis became a 2008 Chevrolet Tahoe. Thank God for this truck.

When I checked the ground cable for tightness at the battery I saw looseness at the actual crimp fitting that holds the negative cable in place.

Unfortunately, this is not the only problem I found with this cable. You can get an AC Delco replacement cable here.

Chevrolet Negative Battery Cable

I'm no stranger to complicated automotive electrical problems. Nevertheless, the issue with this Chevrolet negative battery cable had me scratching my head. Let me tell you why.

As I mentioned the connection where the cable goes into the battery terminal was loose. So I thought I'll just fix this connection and everything will be fine.

However, that wasn't the case. I pulled the cable out, cleaned the end of it and then soldered it back into the battery terminal.

Unfortunately, the intermittent electrical connectivity of the truck remained. So I went to the other ends of the ground connection.

One is located on the frame of the truck and the other is on the engine block. We'll get into how to find these connections in the next section.

After performing the same clean and solder repair of the ends of the cable the problem persisted. At this point I realized that I would have to get a new cable.

A Chevrolet negative battery cable from the dealer costs $100. Highway robbery if you asked me. You can find factory type cables on Amazon for less than $40.

We fixed the truck by replacing the battery cable. It appears that water somehow infiltrates the covering of the cable and rots out the cable from the inside.

This is not the end of the story, because the positive battery cable looks identical in construction to the negative side.

When I grabbed the positive cable and started wiggling it, I got a couple of dropouts of the electrical system.

It's for this reason that I think you should seriously consider replacing both battery cables to eliminate this Chevrolet intermittent electrical problem once and for all.

Replacing the GM Negative Battery Cable

Chevrolet Engine Ground LocationChevrolet Engine Ground Location

Let's talk about the negative side first. The battery is on the passenger side of the engine compartment near the firewall.

The negative cable has three total connections and a three wire sensor also plugs into the cable itself.

The battery connection is self-explanatory and tackled first. The next connection becomes the large 15mm at the engine block. You can trace the wire down and find that it's mounted to a stud.

The stud threads into the block near the front corner of the cylinder head. It looks like the nut will come off, but when you start wrenching it out the whole stud usually comes out with the nut.

The final connection on the ground side is a little harder to reach. It mounts to the front inside  frame section out near the radiator on the passenger side.

You can get it from the underside of the vehicle. However, there is a lower plastic shield with four 7 mm bolts holding a cover to protect the underside.

After you remove this panel you'll be able to reach the 10 mm bolt holding the ground cable to the frame. The new cable comes with the retaining clips in the right places.

You want to make sure that you tuck the cable in just like they did from the factory. I’ll go as far to say that the new negative battery cable features an improved design. This should keep the water out and you shouldn't have to worry about repeat failure.

Replacing the GM Positive Battery Cable

Chevrolet Intermittent Electrical ProblemChevrolet Intermittent Electrical Problem

New positive battery cable for older Silverado here. The positive battery cable on these General Motors trucks includes the 175 amp mega fuse on newer models.

Although the fuse itself isn't the problem, the connections to it are. Again, I found a loose connection.

In fact, I found the lug loosening up that goes into the fuse itself. This was unexpected.

Instead of tightening the connection or replacing just the mega fuse and being done with it, I started looking at the positive cable.

Do you know where this runs to? That's right, it feeds the main fuse box in the engine compartment on the driver side.

This means an interruption in power through this cable can take out any of the individual systems fused in that main relay and fuse box.

The likely hood of the positive cable as the root cause of a Chevrolet intermittent electrical problem just got a boost.

Interestingly enough, when people have problems with the General Motors positive battery cable they often complain about the power door lock actuators activating by themselves.

Chevrolet Intermittent No Start Problems

On some Chevrolet, Cadillac and GMC truck models there’s a separate section of cable that runs to the starter solenoid. Here's a new solenoid cable for Chevy Silverado 2007 1500 LT.

On some of these models this connection to the starter solenoid becomes integrated into the main positive battery cable. You’ll have to check and see which type you have on your vehicle.

I've heard of people complaining about intermittent no starts from failure of this positive battery cable.

unfortunately, this type of intermittent electrical problem can throw an experienced technician in the wrong direction.

When these parts malfunction the airbag light can come on. In addition, the trucks main computer can set various check engine light codes that have nothing to do with the actual malfunction.

These erroneous symptoms can set a technician on the wrong path of diagnosis from the very beginning.

If you own a Chevy truck, take a look at this related article about GM ignition switch problems. These issues can cause the dash warning lights to flicker and engine stalling.

Question: What causes Chevy truck intermittent starting problems?

Answer: We often find problems with the ground side battery cable or connection integrity. Corrosion at the connection, water intrusion into the cable and loose fasteners cause intermittent electrical issues that can also lead to intermittent starting problems.

Question: My Chevrolet truck intermittently looses electrical power. Why?

Answer: The positive side battery cable can suffer from the same corrosion issue as the negative cable. We often see evidence of this at the 175 amp mega fuse located near the positive terminal of the battery.

Question: Why does my Chevy Silverado click, but wont crank or start?

Answer: Some year Silverado trucks have a separate section of power cable that runs to the starter solenoid. This can also have corroded connections or moisture infiltration causing high internal resistance. However, a weak battery or failed starter motor also remain strong possibilities.

Author bio : Mark is a retired ASE certified master technician, Chevrolet Professional Service Council member and the founder of FixMyOldRide.com. Watch the video on the about Mark the mechanic page to see his credentials, awards and certifications for yourself. Mark hand writes all of the articles on FixMyOldRide.com unless indicated otherwise.