So I have a set of digital gauges as well asn an LC-1 that are wired into the cigarette lighter power source. Now I know that this isn't right for the LC-1 due to sensitivity but am finding that when i turn the headlights/foglights on/off or try to lower/raise windows the load causes the digital gauges to change their readings. This could also be caused by the oil pressure/temperature senders for those gauges being wired into the same power source.

My question is - is there a voltage source that is regulated in the car to avoid these issues? What would be the BEST place for me to wire my oil pressure/temperature senders in as well as my gauges and the LC-1.

I have done a LOT of searching but am having no luck with definitive points for this - any help would be greatly appreciated.

Thanks,

Sid

So I called Innovate and they said that the cigarette lighter is fine for the switched 12v. Then I called the gauge manufacturers and they said I should pull the 12v from the fuse box.

I am so confused. Now I am thinking that the issue may lie in the fact that both gauges, and both senders, as well as the lc-1 pull 12v from the same source. Am I overloading that one wire?

I'm no electrical guru, but it sounds like whatever you're tapping for ground might not be adequate. I'd recommend double checking your ground, and maybe even doing the grounding mod. http://forums.nasioc.com/forums/showthread.php?t=674153 If you do that, you shouldn't have any trouble with dimming or skewed readings.

Problem is I've grounded to the engine block AND I have done the grounding mod...

Problem is I've grounded to the engine block AND I have done the grounding mod...
Wow. You just completely nuked my theory. haha I'm clueless as to what the problem could be at this point.

I may just be spewing bs, but could this possibly be psychological? Perhaps you could hook all your gauges up to a separate battery and see if the problem persists even when the system is completely isolated? Probably not what you're looking for, but it's just an idea.

If you are sure the grounding system is ok then you could try running a test power jumper directly from the battery to the power lead of the gauges to see if there is a power wire resistance loss causing this. Use about a 14 gauge wire, preferably with a fuse on the battery end.

this is a very good idea! I will try this and report back. Others?

If you are sure the grounding system is ok then you could try running a test power jumper directly from the battery to the power lead of the gauges to see if there is a power wire resistance loss causing this. Use about a 14 gauge wire, preferably with a fuse on the battery end.

It's an easy thing to try and check the results to see if the power side of the circuit is the trouble. The same could be done for the ground if needed.

good idea. Something else i noticed is that once i turn the engine off the pressure gauge reads about 10 to 12. Before the rewiring it would be 0. Im thinking ground problem now. Any input!

It's an easy thing to try and check the results to see if the power side of the circuit is the trouble. The same could be done for the ground if needed.

Well if you are saying the gauge is reading pressure after you tied the power wire to the gauge directly to the battery remember you have bypassed the ignition switch, and power is continuously tied to the gauge. You can't leave it like that, it is just to see if that clears the trouble.

No no, this is when wired through the cig. lighter that it still reads a bit of pressure. Is this an indicator of a bad ground?

I have to wait until this upcoming weekend to test out the direct wiring - got friday off :banana:

Well if you are saying the gauge is reading pressure after you tied the power wire to the gauge directly to the battery remember you have bypassed the ignition switch, and power is continuously tied to the gauge. You can't leave it like that, it is just to see if that clears the trouble.

Before I read the body of your post I was going to suggest the clock cable. It provides constant 12, switched 12 and ground all in one nifty package right on top of the dash. I installed gauges in this location and never had problems with voltage dip.

Just curious, why are you turning your headlights off an on?

Before I read the body of your post I was going to suggest the clock cable. It provides constant 12, switched 12 and ground all in one nifty package right on top of the dash. I installed gauges in this location and never had problems with voltage dip.

Just curious, why are you turning your headlights off an on?

I used the clock cable for the constant 12v, and the cig for switched. I turn the headlights on at night and off during the day? I don't know how to better answer you (have DRLs disabled).

I turn the headlights on at night and off during the day?
Why not just leave the headlights on at all times?

i think drls look silly.
I sent the lc1 in to be tested over another issue and am going to test again over the week, will update.

Does anyone have a how-to on this??

I was planning on installing the LC-1 and XD-16 A/F set and using what I learned from the Defi gauge walkthrough on this forum. Is taping the radio harness a bad idea for the AFR?

turns out the lc-1 controller was bad so this weekend will reinstall and test.