28 replies to this topic

[RobT5.]

Hey guys, trying to install a msd lazer boost gauge.

So far I've ran into a weird problem,

If I run the gauge directly from the 12v batter when I turn the car on it reads correctly (vac)
If I run it from the wires that were illuminating my old boost gauge it reads 10 low. (from the light switch)
^ that way worked like this, the gauge's light didn't turn on until you flipped the lights on, either the drl's or the headlights. (old gauge)



Read something about it needing to be on while cranking or some crap, almost like it needs to be running as soon as the key goes in?
"NOTE: The RED wire must have 12 volts while cranking and when key is ON"

Anyone have any experience with this gauge and can shed some light on how to wire it up?
Never had an electronic boost gauge before so yeah.


Old one was analog so the wiring was just for the bulb.

[Aequitas_Veritas]

So your old gauge bulb wires, are they hooked to the dimmer? If so they its feeding between 2-12v to that power wire and the new gauges is going wtfbbq I need 12v.

You need to hook the gauge to a 12v IGN wire behind one of the dash switches. I believe its a pink wire.

Actually, it probably wont mess up the gauge, but try using your dimmer to control the vacuum. That might be fun

[RobT5.]

So your old gauge bulb wires, are they hooked to the dimmer? If so they its feeding between 2-12v to that power wire and the new gauges is going wtfbbq I need 12v.

You need to hook the gauge to a 12v IGN wire behind one of the dash switches. I believe its a pink wire.

Actually, it probably wont mess up the gauge, but try using your dimmer to control the vacuum. That might be fun

but the pink wire is controlled by the headlight switch right?

Aka means I need to have either the drl's on or the headlights on to use the gauge?
Ill go mess with the dimmer to see if it controls the vacuum right now!

[survolvo]

Why not just run it to the cig lighter ad bridge off of there.

[RobT5.]

Did not even think about that...

Thats on as soon as the key goes in right?

But yeah the dimmer switch controlled the voltage

[survolvo]

cig lighter turns on at Pos 1 I think.

[RobT5.]

Well I guess it's off to try that then...

This is a bit annoying

Works fine if I tap straight from battery before turning on the car, doesnt work well if it gets power after car is cranked.

[RobT5.]

That didnt work, soon as you get to III it turns off then back on once the car is on.

Same with the radio.

Which means once its on it goes back to 10less wrong vac.

[Aequitas_Veritas]

No the pink (not 100% on color, I always check with a meter first) wire on the back of say the TRACS switch is 12v ignition which means its 12v constant (no dimming) and comes on whenever the ignition is tuned on. Its also much closer to the pillar then the cig adapter.

[RobT5.]

92.4 °F

Feels Like 103 °F

^

im trying to stay out of the sun if possible.
I tried the pink one going to the back of the dimmer.


But like I said in previous posts, it seems like as soon as the power cuts out right before the crank the gauge goes wonky and reads low.
Which is why I am looking for a wire that has constant 12v from the moment the key goes in, or the moment the key turns to pos 1-2 and all the way thru crank.


I will try the wire on the back of the tracs switch once im done with lunch.
You are talking about a constant 12v wire which means were not talking about the illumination wire.

Sounds more probable.

[RobT5.]

Got it to work.

but it wont turn off when the car turns off.
Tapped into constant 12v coming off the remote start module.


the pink wire is no good. it only turns on if the drl's are on.
Looking for a way to run this without having to have lights on.

[Aequitas_Veritas]

there is definitly a color that has 12v on IGN what other colors were off the tracs?

[RobT5.]

2 greens (together same spot) and 1 black (ground)
got bored put red in greens and it threw the trac's light on the dash

[survolvo]

almost page 2..... still no working..

[RobT5.]

Is there a wire that as soon as you put the key in or it hits pos 1, and all the way thru to start up it has 12v without dropping out or turning off.
at pos 3 right before crank everything cuts out.

I just really need to figure out what hits 12v when you insert key and stays 12v all the way through till you turn the car off.

What about the circle light around the ignition.

[RobT5.]

Well that was fun, looks like i'm wiring a switch in with the 12v constant wire going to my remote start (ill just tap into that plug and put an inline fuse)
and then ill ground it somewhere. Probably using the same ground as the remote start.


Sucks ill have to use a switch unless someone knows how to do this.


went from 103, to raining its ass off. So now im waiting for that to stop.

['93 Dave]

a cheap multimeter would be helpfull pinpointing which wire is getting power at what key position (mine was pink for what its worth, my gauge lights are on when the parking lights are on or the headlights)

[RobT5.]

Yeah same thing with my lights, but for some reason that "off" right before crank restarts the gauge.

As it sits now, which I really dont want to do, I might be putting a push button switch on/off, onto the gauge piller right next to the gauge. like top left of gauge, so I dont have a switch sitting on top of it, or side or bottom.

Maybe wire a blue led somewhere annoying so I know to turn it off before I get out

unless someone knows how to do this.

[RobT5.]

Tapping into ignition coil....
Yay or nay?

Josh (vivalavolvo) says DO ETTTTT.
Hes an electronicy kinda guy so I say maybe.

1 way to find out going to test that theory tonight.

[MattyXXL]

What about the Lines to the fuel pump relay?