The_Honda_Guy

Was doing some thinking here on my girlfriend's 97 DX. I load tested her battery the other day and found it to be at 8.6 volts at 250 CCA, which means it's getting weak. Decided that with winter coming up we should replace the battery. We are planning on going with an Optima Yellow Top Group D51 battery and mounting it in the stock location. We were talking about relocating it to the trunk, but for this car being a daily driver and the good location of the stock battery we decided against it. I took some measurements thinking maybe we could fit a bigger battery in the stock location, but there's no size that's only slightly larger than the Group D51 size that will fit. I currently have an Optima Yellow Top in my Daihatsu and love it to death. Never corodes, can be re-charged without depleting it's maximum capacity, and is very useful when using upgrading stereo equipment.

My next thought was to upgrade the stock terminals to some better ones. My plan is to use some gold-plated Monster Cable battery terminals. I'll have to do some searching around online for them, but I'm sure I remember a website that sold them.

And lastly I decided that while I'm going over the electrical system that I could re-do some of the grounds in the engine bay. From what I've seen, there's only 3 major grounds - battery to chassis, transmission to chassis, and head to chassis. When I did this with my RX-7 I used 0 gauge welder's cable and soldered on my own copper o-ring terminals to the ends. The welder's cable was awesome since it's very flexible for how thick it is, and it's pretty cheap, like 2 dollars a foot.

Are there any grounds I'm missing? What did you guys use for cable? Anything else I should consider doing with the electrical system?

lluks_844

Thermostat ground, but thats on the engine harness. I dont see a need to mess with that one.

The_Honda_Guy

****, forgot about that one. I actually remember now that when I changed the thermostat in the car that I took that ground off and cleaned it up with some emery cloth and put it hooked it back up. IIRC it was a small ground, like 18 gauge or something, so it wasn't as significant as the others I listed. But of course, thank you for reminding me.

The_Honda_Guy

Well, did some more looking around on this.

We are for sure going to with the Optima Yellow Top D51R battery in the stock location. We may end up getting one of the nice billet aluminum battery trays down the road but for now we'll stick with the stock one.

After that we plan on swapping the battery terminals to some of the nice gold plated ones. We'll probably end up getting some from Monster Cable.

And lastly, we plan on re-doing all of the engine grounds besides the thermostat ground with 0 gauge welder's cable and some nice copper o-ring terminals soldered and heat shrinked to the cables. Also, I will probably end up re-doing the power wire that goes from the starter to the battery in the same fashion.

Lastly we plan on hooking up a voltmeter to keep track of the charging system and putting in on the A-pillar.

I realized we could also do a wire tuck, but since this is a daily driver, I'm not going to go through the hassel of that, not to mention it can cause issues down the road. Besides the battery tie-down, tray, or relocating the battery are there any other electrical system mods I could perform?


Modified by The_Honda_Guy at 10:46 AM 11/16/2008

94EG8

I beg to differ, that thermostat ground is the ground for the ECU among other things, if its bad it causes a no start condition that for the most part mimics a bad ECU. Now the valve cover ground, that is pretty insignificant, half the time they aren't even grounded. (look at a beseries engine sometime, if you ground it to the proper ground point on the valve cover its not really grounded, the entire valve cover is insulated from the head with a rubber gasket.) Transmission ground is pretty important, of you really want to improve the grounding run a large ground straight from the battery to the engine block.

The_Honda_Guy

Well, I shouldn't say that it's insignificant, but more the fact that there's no way to really re-wire it. I realize it is important, but the fact that it's run all the way through the wiring harness means that to re-wire that ground, you'd have to tear the harness completely apart all the way to the ECU. Of course I'm going to remove it, wire brush it, put some di-electric grease on it, and tighten it back up.

What would be the point of running a ground from the battery to the engine block, especially since it's already got the main ground on the vehicle chassis? To me, the chassis is a better ground than the engine block.

94EG8

Well i'd leave the original ground from the battery to the chassis, but i'd add one to from the battery to the engine block. The starter get its ground from the from the short ground that goes from the chassis to the transmission. It just leaves you with one less point of failure (ground straight from battery to block as opposed to ground from battery to chassis, to ground to block.)

The_Honda_Guy

So, available mods to perform with electrical system are as follows:

Relocated battery
Perform wire tuck
Replace battery with bigger size
Replace battery terminals
Aftermarket battery tie-down
Aftermarket battery tray
Re-wire grounds and other wires with larger wire
Have stock alternator rebuilt to put out more power
Replace alternator with higher output aftermarket one
Install voltometer

I think that would about cover things as far as electrical stuff with the car. Are there any mods that I'm missing?