Boost Gauge Install

Post by **micah861** » 04 Feb 2012, 12:22

Hi there!

I haven't been on here in a long while because School and other things got in the way of my Volvo Hobby! But things have calmed down, and a week ago i bought a 98 S70 T5M.

I'm moving my boost gauge over from my 94 850. Are there any plugs in the firewall i can feed my line through, or will I have to drill. On the 850 I drilled a hole a couple inches above the throttle cable.

I'm also very poor in the electrical area, where should I wire the light for the gauge, so it can be controlled with the dimmer?

Thanks alot for the help!

D_V_ENT850R · Post by **D_V_ENT850R** » 04 Feb 2012, 13:07

For the light just hook it to the illumination circuit for the radio! I hooked mine up to the stock boost gauge hose! Unless you try to feed thought the pass through harness the hole drilled maybe your option!

Post by **matthew1** » 04 Feb 2012, 13:33

Just did this. What's displayed below in my photos isn't the final product, so to speak, but more of a "proof of concept". I have an IPD A-pillar mount that is going in soon to house the gauge. Then the wiring and tube will be hidden and look professional, no silly double-sided tape to keep the gauge attached to the pilar.

You can go through the firewall like I did, or do it the smart way like D_V_ENT850R and tap into the line that goes to your boost gauge on the dash. You should be able to find it under there somewhere.

For wiring, I wired into the dimmer switch (pink wire on my '97). Works perfectly, looks fantastic. For wiring done right, see this car wiring topic I started to know how to do it right next time.

Next up for me, manual boost controller

.

Post by **micah861** » 04 Feb 2012, 14:10

Thanks guys!

I went ahead and drilled the fire wall, above the throttle cable. My 850 had a boost gauge, but unless i'm blind as a bat, there is no boost gauge on my S70, so I went to the vacume tree. I think i'll copy Matt for wireing the bulb. I have more wires than I see in your picture. I gess ill just back probe them with my test light and see which one is power/ will dim. I also have the IPD a pillar, i think it's going to look really good, just kind of bare unless I get two more gauges!

Post by **matthew1** » 04 Feb 2012, 14:55

Oh I'm sorry. I forgot S70s don't have a factory boost gauge.

Let us know which wire does the dimming trick.

Post by **micah861** » 04 Feb 2012, 16:51

Turns out it was the pink wire. My connector can come apart and fold on the side (see picture) which makes it alot easier to connect the new wires to the original without cutting them.

Then put the gauge cluster up, and ta-dum!

s70glt novice[Will] · Post by **s70glt novice[Will]** » 04 Feb 2012, 20:47

You guys are so lucky. I got the boost gauge kit from ipd, and apparently the little wire splices dont work, so no lights, and the guide failed to mention (although i'm more at fault for being a dumbass and thinking otherwise) that there was wiring in the A-frame. Needless to say, when i drilled, the drill decided to shoot forward and sever the red wire, and damage another. So no interior lights, boost gauge lights, and whenever opens to glovebox or sunblocker mirrors, the door open sound comes on.
XD. Got some work to do some weekend... *sigh* I break more things then i fix... Oh, the perils of car tuning! Alas!

Post by **micah861** » 05 Feb 2012, 13:42

s70glt novice[Will] wrote:You guys are so lucky. I got the boost gauge kit from ipd, and apparently the little wire splices dont work, so no lights, and the guide failed to mention (although i'm more at fault for being a dumbass and thinking otherwise) that there was wiring in the A-frame. Needless to say, when i drilled, the drill decided to shoot forward and sever the red wire, and damage another. So no interior lights, boost gauge lights, and whenever opens to glovebox or sunblocker mirrors, the door open sound comes on.
XD. Got some work to do some weekend... *sigh* I break more things then i fix... Oh, the perils of car tuning! Alas!

That's rough! Electric fail! Is that all going to be difficult to take appart? At least there is no air bag in there!....granted you probably wouldn't have been drilling on it if there was...

s70glt novice[Will] · Post by **s70glt novice[Will]** » 06 Feb 2012, 00:30

Its not too bad, the only thing is i'll have to re-wire the boost gauge and re-secure the vacuum line. Just a fair warning

Totally worth it to see my boost shoot up

*edit* In the day time that is...

db130 · Post by **db130** » 06 Feb 2012, 09:14

NO NEED TO DRILL THROUGH THE FIREWALL, guys!

there's a factory pass-through underneath the master cylinder:

Culled from IPD's boost gauge install instructions:

"Under the hood, on the driver side of the engine compartment, locate the plastic fuse box labeled
“MAIN FUSES”. Use a small flat blade screwdriver to depress the tab locks (one on the front and one on
the side closest to the fender) and carefully pop the fuse box out of its bracket. Lay it to the side to
gain access to the pass thru below. The pass thru is a plastic flexible tube that passes through the
firewall, it has a rubber cap on each end with several nipples on each cap. Locate the end of the
pass thru and pull the entire rubber cap free from the plastic flex tubing, this will allow the gauge
tubing to pass through from the interior of the car. Leave this open for the time being."

Once the tubing for the gauge has been pushed through the passthrough, cut off the tip of one of the smaller nipples and feed the tubing through the open nipple.