KLR

I'm getting ready to install boost and a/f ratio gauges in the cubby below the stereo. I'm clear on how to splice the KLR line (using a 7/64" rubber tee), where to pull the dimmer controlled lighting (the ash tray light), and where to connect the o2 sensor and ground wires for the a/f gauge (pin 24 and pin 28 of the DME harness).

However, I haven't seen any posts in the archives that clearly document where to splice into a fused 12 volt supply. Obviously, the radio is an option. But, I've seen people hint at being able to get it from the DME harness as well. This strikes me as a cleaner approach, since I'll have to run two wires (ground and o2) over there anyway.

So... two questions: Am I thinking about this the right way, and which pin is 12 volts fused?

eclou

I pulled mine from the clock power supply. The clock has 3 power wires - constant, key-on, and light dimmer.

Ski

DME pin 18 or 35.

ewainwright

I was afraid to tap into the computer or radio as I can really screw up (for proof ask my ex-mother-in-law).

I had to take apart the plug and splice a line (not actually cutting it rather slicing off its cover) going to the DME to get a signal for my A/F gauge. As I had mental pictures of my car being towed once more, I also used the ashtray light with a fuse in the line.

For me and my lack of gifted abilities, its always a good idea to limit the possible mayhem that I could cause. Again, for proof ask my ex-mother-in-law as I am still working on removing the splinters of wood out of my #%& left by one of two of her broom sticks. Yep, she had one for each hand.

slim_boy_fat

Hey i am just about to do that once the gauges arrive, any tips will be welcome!!

Danno

Either DME-18 or 35 will give you +12v (big red/yellow-stripe wire). The ground can be DME-17 big brown/yellow-stripe wire. Be careful about the O2-sensor signal wire. It's a coaxial shielded cable, so you can't use vampire taps or you'll short out the O2-sensor. Some people dig through the outer coax shielding and extract the center wire, but that's messy and you can end up with shorts and interference. I prefer to tap into that signal wire inside the DME connector about 1/4" from the end where the center wire has been separated from the shielding braid. Use wire-stripers to push back the insulation and solder your O2-sensor wire there (don't forget to thread it through the rubber grommet 1st).

KLR

Danno, I had read that about the o2 wire in prior posts and on your website. For the other two, I assume it's easiest to just splice the wire before it enters the DME harness? I think I'm willing to go through the pain of extracting the wires from the DME harness x3 (of course, I've never done it, so I may have a different opinion after I extract the first) if adding it in directly to the harness yields a more professional installation. What are your thoughts? How do you usually wire these things?

ewainwright, did you use the ashtray light for both the 12-volt fused and the dimmer? I've been assuming that the ashtray light is only supplied with dimmed power from the rheostat and a ground (like a dining room chandelier on a dimmer).

Can I get everything I need except the 02 signal from the ashtray light? Please say that it is so!

KLR

OK, not to butcher my own thread, but according to my factory manual, there should also be an unused ground underneath the radio to supply the equalizer if installed (my car never had one). Is this true? This seems like a convenient option to avoid splicing any ground wire.

KLR

Bump.

Danno

" if adding it in directly to the harness yields a more professional installation. What are your thoughts? How do you usually wire these things?"

I like to tap into the power & grounds about 3" away from the DME connector with vampire taps. Then thread the O2-signal wire through the rubber-grommet into the DME-connector. Simple way tap into that is just to find the center wire of the coax cable. Then set a set of wire-strippers to close just enough to cut into the insulation, but not through the center of that wire. Then push it sideways to shove the insulation aside, exposing the inside. Then just wrap your O2-signal wire around that and solder. Wrap some electrical tape around it, reassamble the DME-connetor and that's it!

I prefer doing it all at the DME connector because it's quick and simple. No need to run 3 different wires to three different places. Also running a bare unshielded signal-wire out to the O2-sensor in the engine-compartment is sure to pick up interference from the coil & plugs, giving you a different reading than what the DME sees.

KLR

Thanks, Danno! It's good to get an affirmation from the pros.

slim_boy_fat

KLR i am about to fit a boost and A/F tomorrow, how did you get on? Any tips mate?