As most of you know I am a glutton for punishment when it comes to projects.

Been woring on a diesel Blazer (84) and just this weekend decided to swap out the body in favor of a nicer cleaner one I found.

OK
The issue right up front is that the project truck is a 6.2 diesel truck YEAAAAAAAAAAAAAAH and the truck that ahs the good body is a gasser. BOOOOOOOOOOOOOO

These facts dictate the real need to swap all the wiring harnesses from the 84 diesel's original body into the Donor body.

The engine wiring is fairly easy to get to but, on the other hand all the wiring under the dash is a real @#$%^& to get at.

Been carefully disecting the diesel rig over the last several days and discovered a lot of real issues with the wiring.

First off, the wiring on these older trucks is not all that complicated but its just packed in under the dash pretty well.

The dash has to come all the way apart to gain good access to this stuff too.

Once the cluster is out, then the pad comes off, the glove box comes out, dop the steering column down a little bit to gain more room.
All the HVAC ducting comes out and WOW you can actually see what your working on.

The issue that brought me to writing about this is simple. ELECTRICAL ISSUES.

Last eavening while slowly unhooking plugs and tracing out where stuff goes, I decided to remove the ground BUSS BAR over by the drivers side AC duct. WHHHHHOOOAA once the sheet metal screw was out it was real easy to see a real pile of corrosion under the Buss bar where it contacts the sheetmetal body.

Looking at the area one would never see this issue.
Also to get to this stuff is really tough too unless you are getting serious about removing half the truck.

Further investigations revealed that many of the connectors had corrosion in them.

Most all can be cleaned with contact cleaner and dialectric grease applied to restore them to full function.

With many of our trucks reaching back 20+ years or more, the issues with wiring are becoming almost epidemic.

For the folks that live in the salt belt, the issue is even worse.

Here at TDP we are always telling folks to check Grounds and other connections before spending $$$$$$$$$$$ on repair parts.

This little excercise last eavening really brought this stuff home.

The practice of using the sheet metal body as the ground has been a practice in the auto industry forever,sadly it has its downside.

Over time, the various joints all around the vehicle accumulate dirt, moisture and corrosion and this stuff all goes to work destroying what was once a nice system of grounds that kept all the onboard devices working.

So after 20+ years, things like the electric windows, heater blower and other goodies all start to suffer.

Now spring forward into the age of the computer, do we have any better grounding, nope not all all. The computer controls hate poor voltage supply and bad groun ds can drive this stuff nuts.

The +++ wiring usually has weatherpack connectors with the cool little bellows to seal them. What about the grounds???? Just a sheet metal screw with a star washer in many cases, buttoned up to the good old sheetmetal body.

We speak of checking all the grounds when looking for electrical issues.

OMG there are grounds in these things that have not and will not see the light of day since the truck was assembled at the factory many long years ago.

To totally disect a rig to check the wiring is not something that most folks are willing to do or even think about.

The only real way to even know where most of this stuff is, requires the factory wiring diagram book and even that does not always tell you exactly where the stuff is.

Its amazing at how nasty so many of the connections were that I pulled apart.

No wonder the tailgate power window had failed several years ago.

Keep in mind, that when connections get corroded, the voltage available drops, and as that happens, the amperage draw goes up. With this comes heat and ultimately component failure.

The once gentle whirrrrrrr and very quick action of the power windows become a noisy growl with the window requiring a helping hand to get it down and then a little prayer that it will come back up again.

I will also add that the designers of these things had not planned on someone taking them totally apart.

These vehicles go together in LAYERS with the stuff you will need to service being burried under a pile of stuff you will never need to touch.

OMG what a task to strip out everything in the way of wiring, inspect it and reinstall it.


Hope this gives some others a little insight into what happens behind the scenes as your rigs sits out in the rain year after year.

Dialectric grease is good stuff.

A great plan and one I intend to employ during the reassembly of my Little truck is to add a ground wire to the ground Buss bar that runs to the NEG battery terminal.

This should go a long way to making things work far better.

Sadly the Buss Bar ground fastens to the inner cowl, then this is ground by metal contact to the fenders and if they are still there, ground straps that connect tha body, fenders, frame and engine all together.

So many times during repairs these ground straps are either removed to gain access or damaged or just tossed off into the corner.

Any ground strap needs to be there for a specific purpose and was installed at the factory for that specific reason.

The factory does not spend $$$$ on anything that does not serve a real purpose.


Best to all


Missy