2nd Gen Non-Engine/Transmission Gauge Installation--Fuel Pressure, Boost and EGT

[MAYoung]

I am about to install the above three gauges in the 'A' pillar of my 1998. 5 2500. Question one: What is the best routing for wires? Geno's Garage suggests running the wires through the existing firewall hole for the engine-to-cab wiring harness. The fuel pressure sensor has a rather large connector that makes it difficult to fit through the existing wiring portals.



Question two: When tapping into a power supply, what is the best method that produces the most professional results?



Thanks in advance for your assistance.



MAYoung



1998. 5 2500 5. 9L Cummins, 5-speed Manual Transmission--No mods, strictly stock.

 

[DNewell]

Great questions. I have the exact same truck. Absolutely love it. When I ran the EGT and FP, I put everything through the stock holes in the firewall. when I tapped into a power supply, I have a little plastic connector that can be used to tap into existing wires without stripping of any kind. If you are near a auto parts supplier or a car stereo shop, just ask them about tapping into existing wires without having to cut, strip, and then secure with a butt connector. I don't know the technical name for the part, but it is a small plastic connector, about 1/2x1/2 and one side of it has a hole that runs all the way through for the original wire, and the other side only goes halfway for the wire to the gauge. It has a metal piece that actually pierces both wires and then creates a bridge to the factory wire. This is all covered with a plastic cover. Cheap and efficient.

Actually, come to think of it, I think that I drilled a large hole, about 3/4 to run the wires and the FP regulator hose through. On the fuel pressure unit, do you have an electrical one, or is it manual? If it's manual, ensure that you're not running fuel into the cab.

 

[MAYoung]

Thank you Mr. Newell. I have seen the splice kits that will allow you to tap directly into a wire without actually cutting the wire. They simply clamp on to the existing wire with prongs that pierce the wire insulation for contact. I felt that those looked like the most efficient approach but I wanted to get someone else's opinion.



For the boost and EGT gauges, I can slip them throug the existing factory firewall hole. It's just the fuel pressure gauge that presents the problem. I wll study the truck closely to find the best place for tapping a hole. Again, thanks.

 

[aviatorman]

I have an 02/H. O. 6spd that I just installed the Geno's 3 guage "A" pillar with westach guages. For switch power I went to the side fuse panel (see it with driver door open) and went to fuse location #16 , which was a spare slot for me. It is hot with ignition swich on. The lights I got off the back of the light switch and I think the wire color was tan (it will allow dimming when you dim your inst panel lights for driving). Make sure that you use good grounds everywhere as it will make the guages good and steady. For mounting the transmitters, you can fabricate a bracket and use Genos holding fixtures mounted to your bracket. For the turbo boost you can use the hollow bolt from Genos or drill and tap the intake manifold. Cause I'm mentally challenged, it took me all day to do the install. Oh, I forgot to mention that I discarded the original A pillar and used the Geno's stand alone and fastened it with a couple of small sheet metal screws at the top only (since the bottom is sandwitched nicely by the dash). Good luck and your going to love driving/pulling using the guages.

 

[CTD12V]

I have seen the splice kits that will allow you to tap directly into a wire without actually cutting the wire. They simply clamp on to the existing wire with prongs that pierce the wire insulation for contact. I felt that those looked like the most efficient approach but I wanted to get someone else's opinion.

Check out the Posi-Tap connectors made by Swenco. http://www.posi-lock.com/posiplug.html I think these are a lot more reliable than the "scotch-lock" style of connectors. I was very pleased with the quality of the Posi-Taps when I used them on my installation of cab clearance lights. I think I just saw them in Geno's catalog that came with the May TDR issue. And of course, the usual disclaimer applies . . . I am not affiliated in any way with Swenco, etc.



Good luck with your guage install.



CTD12V

 

[NoSeeUm]

I would only use the clip type connectors in an area were it always remains dry. You are also going to need power for the gauge led's. If you want them to dim, the ashtray light wire is a good spot to get power.



I found it easier to run everything up the A-pillar by sliding the wires (tubes) up from inside the cab side fuse panel. There is a U-shape bracket in the back of the fuse panel, just slide everything up along it and it goes through really easy.



Source Automotive also seems pretty competative in pricing, you might give them a call.



Jim

 

[WDixon27]

i wired my gauge lights to the dash lights and found them just too bright right in my face when i had the cluster where i wanted it, so i used a dash light rheostat from a junk car and put it up under the dash to tweak the gauge lights to the desired level

 

[MAYoung]

Gentlemen:



Again, thank you for all the informative and intelligent suggestions.



I am nearly ready to install in three pillar gauges. I am using the cigarette lighter wire for power when the engine is running. (I rarely use the outlet. ) I have also identified the wire for the dash/instrument lights so the gauge lights will working in unison with the interior controls. I am using the "Tap-It" splicers and "Twist-It" they appear to provide for a good connection. (Wal-mart carries a number of their products in the automotive section. ) I am tapping the wires "downstream" of the fuse box so I believe the instrumentation will be properly fused.



I have also taken the opportunity to replace the clutch interlock switch since its tends to "act-up" particularly when it is snowing in the mountains. I am also repairing the bushings and pivot pin for the brake/clutch assembly. (It seems that even the factory had trouble installing the clip which held the pen in place. )



I am ready to tap the exhaust manifold for the EGT gauge and feel comfortble in handling that task. I have yet to find the drilled bolt in Geno's Garage catalog for the intake manifold bolt.



I have had the truck for 8 years now and the driving force for the instrumentation is the second failure of the lift pump and VP44 injector pump. The first failure was at 79,000 miles and still covered under warranty (California). I did not pay enough attention. It is now failing again at 159,000 miles. Once the new gauges are installed, I am moving on the the injector pump. I can see that I am not even a pathfinder in this experience. I should have check out the failure at 79,000 miles a little closer and I would not have waited so long for the gauges.



Again thanks. I'll let you know when I start it up.

 

[MAYoung]

Gentlemen:



The 1998. 5 2500 was started tonight. Fuel pressure immediately came up to 12 PSI and did not fall below 10 PSI during the test drive.



The EGT was quite cold upon start-up--about 400 degrees. It finally warmed up to 600 degrees and reached about 850 degrees about about a 1/2 hour of driving and flooring it on the freeway.



I thought that the boost gauge tube was kinked because I did not notice any movement at first. I then noticed it move at sudden accelerations that the boost would eventually reach about 18 PSI.



Clearly, the fuel pressure is most important to me since it will allow me to see a lift pump failure before the injector pump is destroyed. My question is this--how does one use the boost and EGT gauge in driving? What else will they tell you? (I have read Geno's Garage testing tips for gauges. )



Thanks again.

 

[Boondocker]

The EGT gauge is critical when loaded. Tempurature spikes aren't a concern, but extended periods of high tempurature are. 1250 degrees is the accepted maximum sustained temp, though I'm much more conservative. I like it under 1000, but that's not always possible when trying to get up a long grade without losing too much momentum.



The other thing EGT gauge is good for is determining turbo cool-down. Shutting off your engine when the turbo is hot can cook the oil. Needless to say, that's bad for the oil-bathed parts. So if your pre-turbo EGT is <300 at shut down, that's good.



Boost gauge is mostly for fun. Once you know what is normal, it could alert you to a boost leak. Overboost is bad, but not likely with stock truck. It takes a lot of fuel to make a lot of boost, so high boost = high fuel consumption.



Gauges are great. Your only regret will be that you didn't install them 7 years ago



Neil

 

[MAYoung]

Again, thank you to all of you for your assistance and advice. I have removed and am ready to replace the VP44 fuel injector pump. I am going to start a new thread "VP 44 Removal and Replacement. " I think that the gauges are going to work out great---as soon as I get it running.

 

[aviatorman]

You will notice when pulling a load that while you can achieve 20" boost, the temperature will climb steadily to 1200 - 1300 degrees . This is not a problem unless you stay in that range too long. So the solution is simple , , , drop a gear and increase the RPM (airflow) and watch the temperature decrease while still maintaining 20" boost. These engines are bullet proof ,,but not bomb proof. The extended high temperatures (combustion) on the pistons will eventually overwhelm the oil cooling jets that cool the piston crowns and thats not good.

 

[2-ND TIME]

low boost

Well Aviatorman mine isn't bullet proof from the factory ( still trying to fix) mine for the last year even with the newly replaced vp44 and 300 injectors won't go past 15 lbs boost this is down from what it did before. What made the biggest difference was the adjusting of the apps, it was at 0. 330 VDC and had 0. 468 VDC on the apps, so the adjustment brought it to 0. 460 after I finished it. I adjusted it right on when I did it initally.

 

[2-ND TIME]

Fuel pressure and gauge install

I have a 4x4 and found two spots right behind the shifter, that I could punch out to 3/4" for myres hub which has an o-ring for water proof conections. I ran a bunch of pairs of #16 wire for switches and low power usage. I am going to install the same so the drilling and tapping is the hardest thing I am looking at, for install. I put a 3/4" liquid tight flex up to the hood further water tight install. Next would be the water tight fuse connections that you will need, one for the fuel pump ( I put two on pre and post fuel filter ) this way I can monitor both sides of the fuel filter. Use fuses for either lighting of gauges with a rheostat or individually if wanted. Radio shack should have this or an electronics store. What ever you do always fuse circuits and bring grounds back to or very near the battery. Can help more if this sounds what you may like.