Big Three Upgrade

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Caman96

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It was easy for me. I have access to what I need to get something like this done. For the connectors, you can buy them on e-bay, although I did make mine.
Yes I’ve purchased these before.
 

kennythewelder

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Yes I’ve purchased these before.
I was talking more about the battery connectors. I did make some of the lug connectors , but did buy some too. The fuse holder, and fuses were store bought. We have a 4x4 shop a block from my work. They do custom work, so they had all the connectors, and fuses I needed.
 

TechNova

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If you are like me and have old GM battery cables laying around ,if you cut the rubber **** off the end and clean up the cable, file down a bit on one end, you get a nice heavy gauge ground strap cable for free. the ring is large on one end if you do that but its a nice way to have free good cables.
That is an improvement, but larger cable with a higher strand count is much better. Really shows when you start adding electric accessories. I did the big 3 on my then stock 89 and thought I imagined the wipers going faster, Kenny confirms it may not have been my imagination.

I have become a fan of star washers, IE style. See them used alit for grounds in later OEM.
 

kennythewelder

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That is an improvement, but larger cable with a higher strand count is much better. Really shows when you start adding electric accessories. I did the big 3 on my then stock 89 and thought I imagined the wipers going faster, Kenny confirms it may not have been my imagination.

I have become a fan of star washers, IE style. See them used alit for grounds in later OEM.
The welding lead I used, is a high strand count wire. Original, I was going to use #4 welding lead. When I saw how small it was, I went up to #2. The salesman at the welding supply said, it's because of the strand count inside the cable. The physical OD of #2 now, is about the same physical size #4 used to be, but it can carry more amps, because it has a higher strand count.
 

AuroraGirl

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That is an improvement, but larger cable with a higher strand count is much better. Really shows when you start adding electric accessories. I did the big 3 on my then stock 89 and thought I imagined the wipers going faster, Kenny confirms it may not have been my imagination.

I have become a fan of star washers, IE style. See them used alit for grounds in later OEM.
GM says not to use star washers for grounds,the next post I will post my proof

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TechNova

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yes because they are using specially coated one time use fasteners. If you know anything about OEM repair procedures, I use them daily, you will know that a recommendation not to do something by one OEM can be a requirement by another or all others. If you know anything about engineers, I worked next to them a few years, you will know that that change orders don't always make alot of sense, I think they change things for job security, show off, or for a perceived problem that may not be serious.
The OEM rivstuds and coated nuts work, I have used them and keep a couple extra new nuts in my drawer. AN OEM application has fewer variables, I have seen rivstuds and nuts not clinch very well causing a poor connection. For a DIYer, a bolt and star washer is cheaper and easier to do properly and will last a long time if done properly and coated properly after the repair.
 

1998_K1500_Sub

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Hey, I have searched but did not find this topic. I did this upgrade on my gmt800 and noticed a difference all around, bc i think the factory put bare minimal effort in grounding these trucks.

So i've got this 1/0 wire, 1/0 - 3/8 copper lugs, heatshrink, a 300 ANL fuse, wire cutter, and hammer crimper. I plan on cleaning up factory grounds too ... a little grinding/sanding, dieclectric, and spray with black tractor paint. Anyone have knowledge or tips for doing the big three upgrade in a gmt400 before i get started? Thanks!

Here's what I've done (but I don't have my notes handy, so from memory) and probably a few others on GMT400 have done.

Be methodical:

- Get a voltmeter / DVM. Cheap ones can be had for... cheap. I use a Fluke 77.

- Connect the DVM's black lead firmly to the engine block / alternator

- Get a pad of paper and make some columns, labeled

(i) battery gnd
(ii) frame (at ground strap, passenger's side)
(iii) body (at ground strap connection, passenger's side)
(iv) alternator output
(v) battery +
(vi) terminal block (driver's side at the fuse holder)
(vii) another body location, you pick (for comparison to (iii) above, as a sanity check)

- Start measuring the voltage at those locations with the DVM's red lead, under at least the following situations:

(a) engine off
(b) engine on, RPM 1200, HVAC off, all lights / accys off
(c) (ditto) headlights on high
(d) other variations as one sees fit, e.g., blower high, compressor on, high-watt stereo cranked, etc.
(e) add your particular situation here

When done, grab a beer, start admire your research and study the measurements.

Look where the larger voltage drops are happening, and focus on those locations for "upgrade" with heavier gauge wire.

I suspect you'll find that the biggest bang-for-the-buck is "beefing-up" the lead from the alternator to the terminal block (driver's side fuse holder) and battery, as the OE wire isn't really that heavy and it's a LONG length of wire.

Otherwise, "freshening-up" some of the ground connections may be required to reduce voltage drops, but of course the voltage measurements will tell you where you need to focus. You may find, for instance, the ground strap from the frame to the engine has excessive voltage across it and needs freshening... or not.

Then, after you've made changes, duplicate your measurements as appropriate and make note of the improvements. Save all the notes, so that you have them at a later time should there be some electrical issue needing attention.

Crack another beer and reflect what you've learned, the methods you employed, and the improvements you've made :)

PS: If you're curious, get a DC-current capable clamp ammeter (e.g., Fluke 36, which I use) and measure the current in the various connections (alternator output wire, ground straps, wherever) while you're measuring voltages. It may give you additional perspective.

PPS: I found both meters on eBay just now for about $35 (Fluke 77) and $40 (Fluke 36). Using both meters together allows one to measure both the voltage and current simultaneously.
 
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Darkimag22

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I'm upgrading all the main power/grounds to 2/0 welding cable as well as installing a battery isolator. This might help you out some...

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