I recently installed gauges in my truck. I assume this upgrade is a pretty straightforward task for most folks here. However I had not installed gauges before, other than my Aeroforce scangauge, so I needed to do some research first. The process is pretty well documented between write-ups on the internet and install instructions from various vendors. However there were several small steps where a picture would have really helped clarify the process for me. So I took pictures during my install and thought I would post here in case it helps any other entry level folks like me.

I used Isspro EV2s, primarily because I thought they would match the factory gauges, and an Autometer pillar pod. I did the usual pyro/EGT and boost gauges, and went with a fuel pressure gauge for my third since I have a ZF5 truck (therefore trans temp is not a major concern). I got the snubber kit for the fuel pressure gauge, and I installed the gauges with the potentiometer dimmer that Isspro offers to enable me to brighten or dim the gauges as needed to match the factory cluster. It’s worth noting, this potentiometer enables you to both use your factory dimmer to adjust brightness of the gauges AND adjust them up or down additionally if their relative brightness does not match the factory cluster. I did not understand this at first and assumed the factory dimmer would be sufficient. But it seems the gauges are often X percent brighter (or dimmer) than the factory cluster, so just adjusting brighter or dimmer would always maintain that percent difference between the new gauges and the factory cluster.

The aspects of the install where I could have used more clarity were:

1) Fittings needed to make a T for the MAP
2) Exact location of hole for EGT probe
3) Fuel pressure sensor fitment on the factory fuel bowl
4) Where to route wires into firewall
5) How much to drill factory A-pillar trim piece
6) Good location for Isspro dimmer
7) Basic wiring and power sources

Forgive me, I know this is really basic stuff for a lot of folks here. Photos to follow...

 

1) Fittings to T into MAP line.

I wanted to T into the MAP sensor hose instead of drilling and tapping the factory spyder because I figured if I messed something up it was easier to replace the hose instead of the spyder. I believe there are some kits available online with plastic Ts and clamps, but I didn’t think to buy one before starting on the install. So I had to make a couple stops at a hardware store to get the right stuff. Here are the parts I used. The gauge uses 1/8” NPT size thread for the sensor, but I found it easier to use 1/4” NPT size fittings and one 1/4 to 1/8” reducer for the sensor due to not being able to find much 1/8” stuff.





2) Location of hole for pyro/EGT probe.

Kept reading folks say there was a flat spot on the bottom rear of the driver’s side manifold. Flat is not really how I would describe that spot, so I checked photos online multiple times. All posts seem to confirm this location. Measured and marked first before drilling. Seems fine now. Note: instructions on tapping indicate you don’t necessarily need to run the tap all the way in.



Measure multiple times...drill once...

 

3) Fuel pressure sensor fitment on the factory fuel bowl.

I am running the factory mechanical fuel pump, fuel bowl and fuel pressure regulator assembly for now. Hoping to upgrade to e-fuel eventually. I understand now the pressure pulses from the factory mechanical pump can damage gauges over time, but I did not order snubber kit originally with my gauges. I discovered the need for it after reading the installation instructions included with the fuel pressure gauge and obtained it after the fact. The snubber kit is now readily available from a sponsor’s site. Before I got the snubber kit I assumed I could just install the Isspro pressure sensor directly into the port on the factory fuel bowl regulator assembly where the Schrader valve is located. However the Isspro sensor is very long and did not really fit well there. If I threaded the sensor directly into the FPR there wasn’t hardly enough room to install the wiring harness plug. I tried a 90-degree elbow and also a T-shaped fitting and none of those orientations really fit well. Once I got the snubber kit I got it worked out. The snubber kit consists of a 3500 psi grease gun hose that lets you move the sensor out away from the fuel bowl and FPR assembly, providing more room for the sensor. I ended up threading the grease gun hose directly into the FPR assembly (careful not to over tighten) and installing the needle value included with the snubber kit, then the snubber, then the Isspro pressure sensor. I found the needle valve to be a bit bulky to include down by the FPR assembly so routed it AFTER the grease fitting hose instead of before. Hope that is okay.

Here's the sensor installed into the FPR without the greese fitting extension hose from the snubber kit...



Here's the actual snubber kit and included components tentatively assembled according to the instructions...



Here's how I ended up routing it...greese gun hose direct into FPR port where Schrader valve installs, up along AC hose, into needle valve, then to snubber, then to T where I reinstalled the Schrader valve in case I ever wanted to use for testing, then into sensor.



Ended up switching to black zip ties, will try to find better picture.

 

4) Where to route wires into firewall

Most articles I found online mentioned routing wires through the knockout on the firewall for the clutch master cylinder, which is not used and therefore just blocked off with an automatic truck. But for a ZF5 manual transmission truck you have a master cylinder there, so the spot is not available for wires. Yes I could have just drilled another hole in the firewall, but I wanted to use a factory hole if possible. Found a couple posts mentioning one such factory hole just to the right of the clutch master cylinder (to the right if you are looking at the truck front to back), but could not find a photo to confirm it.

So here are photos of this hole. It’s covered by a small black plastic cap, which covers a larger hole in the middle and two smaller holes to either side. I used the larger hole to route the wires through and used the plastic cap to recover the smaller holes. I had to enlarge the hole just a bit to about 3/8” using a uni-bit to accommodate the diameter of all the wires. 7/16” grommet was about the perfect size for this sized hole. Here’s a picture of where this opening is located on the firewall, the black plastic cover and where it comes through to the inside of the cab. I removed my accelerator pedal to get better access, and I had to peel back some of my sound proofing material.



Covered by this cap...



Tried to zoom in for the obscure part number. I ended up drilling a hole through this an reusing it to cover the two smaller holes to the sides, as shown below...






I had to enlarge the whole a bit. I think 3/8" was about the right size with a 7/16" grommet. Something like that.

Here's where they pass through the firewall. I removed the accelerator pedal for access and pealed back sound damping material...



5) How much to drill factory A-pillar trim piece.

I had read you needed to drill holes in the factory trim piece, but wasn’t quite clear on why and how much. Now I get it. Wires pass BEHIND the factory A-pillar trim piece, not between the gauge pod trim piece and the factory trim. So there must be holes in the factory trim for wires to go through and into the gauge pod trim piece. I preferred to drill as little as possible into any factory components, so I just drilled the small holes shown in these pictures, in alignment with where the back of the gauges would be, and I got an extra trim piece form a pull a part yard in case I messed something up with mine. Also had to drill the new gauge pod trim piece to match factory screw holes to mount it on top of the factory trim as designed.

Looking from gauge side with pillar pod trim piece laid over top factory trim piece, eyeballed where plugs would pass through, marked, drilled with uni-bit...



From back side of factory trim piece. Probably should have made these a little larger as it was kind of tight to pass wires through...



Need to drill top and bottom also to match holes for screws in factory trim. Held pillar pod trim piece over factory trim, marked from back side, drilled with uni-bit.

 

6) Good location for Isspro dimmer

You can drill a small hole in the factory dash lower trim piece to mount the dimmer. However as stated above I preferred to drill as little as possible into all factory components as use existing holes where possible. My preference for gauge brightness is for them to be exactly as bright as the factory cluster and to dim with the factory light switch. So really I just needed the potentiometer dimmer switch once to match the new Isspro gauges to my factory cluster. Therefore I didn’t really feel the need to mount this switch in an easily accessible location. Figured I would use it only once. If I could use a pre-existing hole, then an out of reach location was fine for me. Ended up using this factory bracket shown below. Not sure if this bracket was originally intended for the baro pressure sensor inside the cab or what. But drilling it out just a tiny bit made it fit the potentiometer dimmer switch perfectly. As planned, I used it once to adjust the Isspro gauge brightness and haven’t touched it since.



7) Basic wiring and power sources.

Wiring really wasn’t as complicated as I thought. Each sensor routes up to the specific pod intended for the specific gauge. For the Isspro EV2s there was a blue bundle for the EGT/pyro probe, and a set of colored wires for the two pressure sensors (boost and fuel psi). And there was a separate red, orange and black combo for power, dimmer and ground. Red-power, orange-dimmer, black-ground.

I realized from the onset it was important to keep the wires for a specific gauge together, so thought ahead to tape them together, since it would be difficult/impossible to tell which like-colored wire went to fuel pressure versus boost pressure, etc. The idiotic mistake I made was, whereas I taped them together, I did NOT label which bundle was from which sensor before running them through loom and through the firewall into the cab. So I had to get a helper to tug on one of the sensor’s wires and see which ones got tight from inside the cab, the label them accordingly. After labeling, routed one gauge's combo to the pod position I chose for fuel pressure and the other for boost.

After sorting this out I kept referring to the “daisy chain” phrase. Appears to me this just means the same power, dimmer, ground combo route to all three gauges in a loop. The way the Isspro EV2 gauge plugs work is you basically build your own plug that goes into the back of the gauge with a press-fit install tool provided with each gauge. The wires press into the back of a plug that pierces through the wiring insulation for you, so no stripping of the insulation required. The way I would describe the wiring is the red, orange, and black combo for ground, dimmer and power go from the fuse panel and ground source, to the Isspro potentiometer dimmer and up to the first gauge, then looped up to the second, then looped up to the third, etc. And each gauge is fed a second set of wires independently from its respective sensor. Here are some photos, hope it makes sense of it. I found the last page of the included Isspro gauge install instructions to be most helpful in this step. Got mine from Clay, instructions available on his site:

(http://www.riffraffdiesel.com/conten...ISSPRO_EV2.pdf ).

Wires from each sensor routed up to the respective pod position...






Then power, dimmer and ground (red, orange and black) wires routed from Isspro dimmer to bottom pod, looped back in and up to middle, then looped back in and up to top position...



Isspro tool for pressing wires into plug (orange is the plug, black is the pressing piece)...



I labeled plugs first to make sure I didn't mess the orientation up when I moved over to the truck...




Wires insert into black tool first, then press into orange plug. I elected to do one at a time at first as the directions recommend. You have to be careful not to press them into the wring position on the plug.



Plug in place, the press/squeeze with plyers.



Plugs with white caps on back and wires trimmed, ready to install into gauges. Then gauges press into pod and align. Then screw pillar pod cover onto factory trim piece.

 

I found a couple recommendations for fuse position numbers to tap into. I used fuse taps, and ended up using fuse positions 3 and 10. 3 for power, 10 for dimming. I tied into the same fuse tap that powers my Aeroforce gauge. Here’s a photo of the two fuse taps. Used the 1-Amp fuses supplied with the Isspro gauges. The Isspro gauges consists of an extra bundle of red-orange-black wires. I did not need these as the red-orange-black combo from the dimer/potentiometer were plenty long enough to go from the fuse panel to dimmer and dimmer to gauges.



Again, I know this is very basic stuff for some folks here. Really impressed by some of the more robust fabrication skills and projects detailed here. Just sharing my beginner-level experiences in case it helps someone else out.

For what it’s worth, I am very pleased with the gauges. They match the factory cluster pretty well, which is what I was going for. I went with black bezels, black background (no color band on pyro/EGT gauge), white numbers, white needles, green lighting hoping for a close to a factory match as possible. Green lighting is pretty much spot-on with the factory color. However the white needle is noticeably brighter white than the factory gauges where the needles are yellowed a bit. The data is informative but not surprising. EGT is under control running around on the stock tune with no load, but gets hot enough quick enough that I am inclined to intercool before going crazy with tuning and any kind of load on the truck. Boost looks decent for a stock setup (high teens, but only over 2k RPMs under load for a while). Matches what I see from my AF gauge and gives me some reassurance I have a reasonably healthy stock setup on which to base subsequent mods. And fuel pressure with the factory setup drops frightfully under load, which is no surprise. Starting pressure is 50, shimming soon. 50 is not so scary as how far it falls under load. Makes me think I might want to do e-fuel before ever starting down the road of custom tuning.

Holler with any questions and if I’ve posted anything that doesn’t look right feel free to correct as the intent here is to help and not hinder other folks’ projects. Hope this helps somebody else going down this road.

Finished product. Will try to get a good picture of the gauges lit and post later.

 

Awesome writeup, thank you so much!
I am sure I will be getting back to this post when installing my EGT/boost gauges.

 

Nice wright up and good pics along with it!

 

I could have used this years ago! NICE

 

Makes my writeups look like crap. Great work!

 

This is really timely, have isspro gauges sitting in my house waiting for the rain to stop. I do have a couple of questions I hope you can answer:

1. The two fuse taps you used, they seem to be pointing in different directions, does that mean on some fuses the source power is from the top and others the bottom? (I want to make sure I'm actually fusing). I'm guessing you just used a multi-meter to figure it out?
2. Where did you get the gauge pod on the column? I've been looking for one (Want to eventually get one more gauge)
3. You didn't say anything about the trim clips, did you find the unnecessary? or were they not included?
4. Edited - What size is the MAP sensor hose?

Super write up and pictures, you answered a lot of the other questions I had

 

 

Thanks for the kind words..

Jeffrey,

1) The fuse taps are pointing in different directions just due to fitment. They are oriented in such a way that they turn the fuses 90-degrees from the panel. So the tap sticks straight into the fuse location, but the actual fuses are turned left and right and insert into the tap from the side. This makes the thing very wide, and I turned them another way they either hit the side of the dash panel or hit another fuse. Yes you could in theory test the slots on the tap to check which fuse powered the original components and which powered the addition. But the fuse tap package indicated the outer-most fuse was for the new stuff. Also You can plug it in with just one fuse in and see what comes on and stays off. Used a 1-amp fuse supplied by Isspro for the gauges. I read a bunch of folks use fuse position 4 for power, but I found fuse position 3 would power up when the ignition switch was on, whereas 4 didn't power up until the truck was started. I wanted the gauges to come on with the key for key-on troubleshooting. Same with my Aeroforce gauge. I can see how many volts I have, RPM, high pressure oil, etc during cranking. And now fuel pressure with the new Isspro gauge.

2) Column pod is made by Autometer. I believe it's actually for Super Duty trucks but fits the OBS column just fine. They make one with a cutout for automatics and one for the manual transmission trucks. It's a bit of a tight fit to get the back of it (toward front of truck) to slip down under the rubber trim piece on the bottom of the instrument panel bezel piece. But it fits, and it holds pretty snug without anything fastening it (they include Velcro, but I did not use it). Did a short write-up on installing it with the Aeroforce gauge on here a while back.

3) I forgot to mention the trim clips. Yes they were included with the 3-pod trim piece. But no I did not use them. For me it held pretty right with the factory trim screws.. It's worth mentioning my factory A-pillar trim piece is not cracked. I've seen several where they break at the bottom screw, then they told hold tight to the pillar. I assume if the factory piece was cracked, then the screws may or may not hold the gauge pod piece as well, which may make the clips more useful.

4) I believe the MAP sensor hose size is 1/4" inside diameter. Someone correct me if I am wrong.

Yes correct, you can just use the factory dimmer only without buying the extra Isspro potentiometer dimmer. I opted to get it from based on a recommendations. The kit includes good instructions on how to wire it differently to dim with only the factory switch, with only the potentiometer dimmer, or both. I used both so I could adjust the gauges up or down to match the factory cluster, then use the factory dimmer to adjust them all together. I always run my factory cluster on full brightness so don't need to adjust much more than once.

I have not looked into programming options with these yet. Guess I thought that was more with the Performax series. Will look into it. Thanks.

 

Can someone tell how big of a difference it makes between installing the EGT thermocouple in the exhaust manifold and the up-pipe? I read about 100°F cool down per 12in of pipe length..

If one bank runs leaner/more rich than the other (which is quite likely), the temperature reading on only one bank might not be very accurate, so I was thinking of installing a thermocouple in each up-pipe. Does anybody have experience with such a setup?

 

I run one in each manifold that is drilled and tapped. In the up-pipes, yes about 100° cooler. In the DP about 200° cooler.