Coelacanth
Active Member
- Joined
- Jul 7, 2014
- Messages
- 522
I finished installing my electric fuel pressure and boost gauges, wiring them in and checking/rechecking, then soldering everything up was not a fun ordeal I want to do often! Anyway, reconnected the negative battery cable, turned the key, and everything is working properly. I guess it helps to be painstakingly methodical. 
I have a few questions about fusebox wiring following my install and some future plans. See the areas marked in green in the attached picture indicating what was changed.
-I used an add-a-circuit with 3A fuse in the ECM-IGN location "P" to provide switched power to both gauges.
-I added a 3A fusible link to a spade connector in BATT port "Q" to provide always-on power to the fuel pressure gauge.
-I grounded both gauges to the location marked "Z" at the top right of the fusebox, with a wire and eyelet I bolted down on top of the cylindrical capacitor that's already mounted there.
Question 1: Is the location "Z" a good ground location?
Question 2: I'd like to install a kill switch. I've read several topics on this already...is wiring a toggle switch into the ECM-IGN circuit in the fusebox a good suggestion? I'm already in there so I'd go that route if you guys agree that's a decent option.
Question 3: The fuel pressure gauge has an optional power wire that's suggested to tap into the headlight wire (brown) so that the unit dims 30% when the headlights are turned on. Is there an easier way to get at this wire--or a similar headlights-on power lead--than trying to get at it from the rear of the headlight switch?
Thanks as always for the advice!

I have a few questions about fusebox wiring following my install and some future plans. See the areas marked in green in the attached picture indicating what was changed.
-I used an add-a-circuit with 3A fuse in the ECM-IGN location "P" to provide switched power to both gauges.
-I added a 3A fusible link to a spade connector in BATT port "Q" to provide always-on power to the fuel pressure gauge.
-I grounded both gauges to the location marked "Z" at the top right of the fusebox, with a wire and eyelet I bolted down on top of the cylindrical capacitor that's already mounted there.
Question 1: Is the location "Z" a good ground location?
Question 2: I'd like to install a kill switch. I've read several topics on this already...is wiring a toggle switch into the ECM-IGN circuit in the fusebox a good suggestion? I'm already in there so I'd go that route if you guys agree that's a decent option.
Question 3: The fuel pressure gauge has an optional power wire that's suggested to tap into the headlight wire (brown) so that the unit dims 30% when the headlights are turned on. Is there an easier way to get at this wire--or a similar headlights-on power lead--than trying to get at it from the rear of the headlight switch?
Thanks as always for the advice!