grounding discussion split from Engine grounds? back of heads

[Flyin Ryan]

Run a ground from your alternator housing to your frame to pickup some extra juice from your alt

 

[dgoodhue]

Re: Engine grounds? back of heads

Re: Engine grounds? back of heads

WHAT???

This suggestion makes almost no sense. In a stock truck (with the battery under the hood, and grounded to the engine), the only electrical 'load' the frame is conducting is the fuel pump, and in a Syclone, the rear lights. Probably 3-5 amps maximum.

There is a ground wire from the core support above RH headlight, to the top of the frame rail directly below the battery. This wire is adequate for the 3-5 amp load of the fuel pump and Syclone rear lighting. No additional ground is needed on a stock truck, as long as these are OK.

NOW: A lot of guys relocate the battery. And I don't think many of them know enough automotive electrical theory to do this "correctly". Ie, have it work without causing problems or issues. The most common "effect" of doing this incorrectly is a burned shifter cable. The guys on here that seem to have chronic electrical issues, have a battery re-locate.

While I have never done a battery re-locate in a SyTy, I've done tons of them in Yachts from 40 to 125 feet. My suggestion for ground cable from the battery would be a #2 AWG min connected to the Transmission Mount bolt that holds the mount to the trans case. This way the frame is never carrying the starter or charging loads. Connections won't become 'resistive' causing voltage drops or intermittant connection problems. This location is easy and closest to the battery in the rear.

With a relocate, don't forget to run a jumper from the engine to the core support ground above the RH headlight. An alternative would be jumper from the trans mount location above, to the mount stud on the crossmember ("around" the rubber of the trans mount). This might be cleaner, easier and just as effective.

The alternator has a very effective ground connection to its mount. The alternator output is rarley, if ever, as much as the starter load. Keep the cables as short and direct as possible on a relocate. And the stock system is fine as engineered, if it's in good condition, and not 'hacked up'. I just don't see where a ground from the alternator to the frame makes any sense. There are much 'better' ways to do it.

Dave

I disgree with some of this. Adding an addiional ground to the alternater isn't complete idiotcracy, however I would be more tempted to add it to the block direct rather than the alternator. I do agree at idle a stock truck doesn't need more output, however at WOT we do see voltage drop by more than 1 volt at the ECM. If you were to follow car audio (I know the typical teens are tools, but their are actual intelligent people in the industry) The recommendation is to beef up the charging system this is done by upgrading the battery to alternator wire, upgrading the battery ground and upgrade engine block ground. The basically completes the charge circuit from battery to alternator and including the return path through ground.

The RH headlight core support ground is for the headlights and horn. I imagine fuel pump is ground through the frame (passenger side front) to the battery. I agree that melt shifter cable is a telltale sign of ground problems, but I would (and did) ground the battery to the frame for relocate batteries and upgrade the frame to engine block (passenger head to passenger frame) In car audio its been proven that the frame is a very effective ground. In a boat (or Corvette) you don't have this luxury so that is why alternatives are used. I think typically frame are equavalent to dual 00 ground wires.

Make sure though the ground is connected to the main frame rails in our trucks (I would even connect the frame rails together with a wire if the ground is on the opposite side from the engine block ground) The support frame rails are riveted/bolted (and the frame is wax coated) that connects them to the frame, these could interfere with a clean ground path back to the battery.

 

[Flyin Ryan]

Re: Engine grounds? back of heads

Re: Engine grounds? back of heads

I've seen a half a volt increase from grounding the alternator case to frame.. as well have other sytyers.. none of them have the battery in the stock location and non of them are completely stock trucks and i'd put money on it that the original poster's truck isn't factory stock neither. It was merely a suggestion going off of my personal results.. plus it takes all of five minutes to do so I figured it would be worth the time.. and in my experience im glad I did it.

 

[dgoodhue]

Re: Engine grounds? back of heads

Re: Engine grounds? back of heads

A lot work was need to quote this thread, I rearranged the thread a little to keep it concise and decide to not respond to certain subject to keep it on topic (Corvettes/Big 3 & frames)

I disgree with some of this.

This thread WAS headed for the vault. But with the use of the word "disagree" it instantly became another piece of inane opinionated supposition. Not worthy of the vault.

Sorry for the rant. But I'm pissed that this "know-it-all" ****ed up what should have been an informative, matter-of-fact thread that could have been preserved for future reference. Instead it's just meaningless BS. Now I've added to the BS. Sorry. DP

The thread can still be split into two threads, I assumed this portion would not be vaulted. I can do it right now if you would like.

While responding to this I went out to my garage to check out my Syclone and fished out my original battery cables. While going through this process, I decide to look at the 92 Typhoon I am working on found out that frame isn't grounded at all, so by luck this atleast helped me out. I think their is a slight difference in negative battery cable on 93 Typhoons, the negative cable the 91/92 has the main cable and 2 small leads (frame and core support)

I do agree at idle a stock truck doesn't need more output, however at WOT we do see voltage drop by more than 1 volt at the ECM.

Please. DO TELL. How grounding the *ucking frame can influence (improve) this voltage reading. (I'm assuming on datamaster, scan tool, etc)? Be careful. It DOESN'T. And the way I'll explain why it doesn't (can't) will make sense to anyone that can read.

First I never said it would increase the voltage. The ECM circuit would not be improved at all by adding the ground cable to the alternator. I thought about it, the Alternator charging circuit would not be significantly improved be adding just a ground to the alternator. My rational was the charging circuit would be improved, The other two legs (of the big three) would probably need to be upgraded as well. After relocating my battery and doing the big three my voltage in Diacom did increase at WOT from 12.6-7V (which is lower than recommended) to 13.3-4V Mine is now higher than most trucks I see (by .2-.3V) Was it because of this maybe, maybe not? It could be that be moving the grounds around clean them up as well.

The RH headlight core support ground is for the headlights and horn.

You sure? It also has the wire from the battery Neg cable under it. THEN it goes to the frame.

Syclone's do not connect that way, I think 92 Ty are the same way. The small negative cable off the battery split into 2, one goes the frame, one to the core. If I had to guess it looks like 14 or 16 guage wires, so the designers did not expect a large current to pass through these connections (both frame and core). The front core support connects to the body through just a few bolt (painted/body clips) to each fender which also connects to the main cab also through a few bolts. I honestly would not expect those to be clean grounds at all. I have an aluminum frame support, so I had to elimate that ground, my truck ran intially with out that ground (I drove it around my driveway a couple times before finish wiring everything up)

I imagine fuel pump is ground through the frame (passenger side front) to the battery.

It doesn't. I didn't "imagine" anything when I wrote this. I had just gone out and looked under the hood of my two trucks to verify how it was configured, when I was unable to find anything in the Helms manuals.

I look at my Syclone and it seems like the fuel pump is grounded to the frame. (Their is a ground connection on the frame, right by the tank) The fuel pump has to be either grounded back through the harness or through the frame.

OK. Here's the crux of our disagreement: I HATE "connections". CONNECTIONS ARE THE #1 CAUSE OF ELECTRICAL PROBLEMS!!! The wire doesn't fail. The terminal doesn't [usually] fall off. The CONNECTION goes bad. It gets loose, corrodes, whatever, and it becomes resistive, causing voltage drop, or intermittent problems.

I suggested going directly to the transmission from the battery. (ONE connection). You suggested battery to frame, then a jumper from frame to engine. (THREE connections). Your suggestion contains THREE TIMES the potential failure modes as mine.

I can see why you don't like connections. I have problem with the Transmission mount. The 700R4 is an aluminum case, its offer little gounding. The crossmember goes to the to the frame through bolts, which probably are coated. IMO You might as well run it back to the engine. This is actaully what got me to respond to your thread.

Make sure though the ground is connected to the main frame rails in our trucks (I would even connect the frame rails together with a wire if the ground is on the opposite side from the engine block ground) The support frame rails are riveted/bolted (and the frame is wax coated) that connects them to the frame, these could interfere with a clean ground path back to the battery.

This paragraph is what set me off. WTF? You advocate how GREAT the frame is, then stipulate: "(I would even connect the frame rails together with a wire if the ground is on the opposite side from the engine block ground) ". HUH? If it's so great, IT NEEDS BAND-AIDS? Now 'your' system has FIVE connections in it. Mine still has only ONE. Why ADD expense, clutter, complexity, AND POTENTIAL FOR FAILURE? I thought the goal is to REDUCE it?

2 of the connections (frame and passnger head) are factory connections anyways and is adding only 3. I currently only have one. I was either going to tie both frame rails together or add another one from the driver rail to the engine block. I do agree with you in that well thought out grounding needs to be address in battery relocation. I do see your concern with the practically of having more connections to fail.

 

[Don W.]

Re: grounding discussion split from Engine grounds? back of heads

Just to stir the pot a tiny bit be sure to solder the term to the wire then clean and TIN (as in apply a layer of solder to the clean surface) where you make the connection to the frame, body, whatever. I personally have NEVER seen or done tinning like this but it used to be recommended. In my experience, solid and tight connections with correct size wire is the key. ANY switch ( a big problem area) needs to be sized for maybe twice the anticipated load or, better, activate a relay. As in the numerous posts on our purple wire starter issues which I've also commented on and promise not to repeat here.:roll: And the Racetronics FP harness setup.:tup:

 

[dgoodhue]

Re: Engine grounds? back of heads

Re: Engine grounds? back of heads

Why? Aluminum is a better conductor than copper, and way better than steel. It's bolted to the engine with 6 bolts. There's no voltage drop between the trans and the engine. And it's 4-5 feet closer.

Copper is slightly better than aluminum, but your right aluminum is a lot better than steel. I looked that up in one of my college books, at the time posting I was think it was poor conductor. I am dead wrong about that.

Another thought, the electrons flowing across dissimillair metals might cause some issues over time, but I am just thinking out loud. I have no experience with that other than remembering some tidbit in the back of my mind and not really remembering the application.