F150 Gauges: Finding the Proper Read Outs

Transmission temperature gauges provides critical information for F150s pulling a heavy trailer. Overheating the transmission fluid is not good and will eventually lead to premature transmission failure. Knowing what the trans temperature is allows you, as the driver, to ease up before anything starts to break down.

The gauge itself is a standard 2-1/16” (52mm) size and uses an electrical sender to measure the temperature. Most aftermarket gauges are calibrated to read between 100-260 Fahrenheit (Verify with the owner’s manual for the specific value, but most manufacturers consider anything upward of 220 F to be overheated). The electrical sensor can be mounted in various places on the transmission, but it is critical to spend a little time thinking exactly where to put it. For example, both the 4R70W and the E4OD transmission have a port located on the driver side that can be used to thread the sensor. Alternatively, the pan can also be drilled and tapped to plug in the sensor. However, it is important to remember any one of these three places will be reading the inlet fluid temperature and as such will be cooler than the actual fluid presently moving through the tranny. If your F150 has a transmission oiler cooler, the transmission cooler inlet line is a great place to work in the sender as it will then be measuring the transmission fluid at its hottest point (or as close to it as possible).

Another good engine parameter to monitor is fuel pressure. Ford factory spec is 38-45 PSI needed for the engine to run normally. Any less than this and the engine may stumble, run rough, or not run at all. Having a dedicated fuel pressure gauge gives an instant and clear synopsis of the condition of the fuel pump and the rest of the system. It is not only useful to have a fuel pressure gauge for troubleshooting purposes, but to also monitor a modified Triton engine that may have been upgraded with a larger pump, injectors, and mass air flow unit. It is not legal to carry fuel past the firewall and into the cab of the truck, thus any fuel pressure gauge you want to mount inside must be electric. Both 4.6 and 5.4L V8 engines have a schrader valve on the fuel rail that can be used with an adaptor to mount the gauge sender.

Late model F150s actually do have an OEM boost gauge built into the digital instrument cluster, and it can be switched in view of the transmission temperature. For those who want the capability to monitor both boost and transmission temperature simultaneously, installing a secondary permanent boost gauge makes complete sense. The factory turbo setup on a 3.5L V6 EcoBoost peaks around 15 PSI and uses an electronic waste gate. Hooking up a mechanical gauge can be done using a T-connection past the check valve on a vacuum line. There are several rubber grommets under the driver dash that can be drilled to pass the vacuum line through.

Having an air/fuel or wideband gauge is useful to have for those EcoBoost F150s that have been modified beyond stock. A proper air to fuel ratio is critical not only for engine performance but also for engine longevity, as an incorrect ratio could cause serious engine damage if left unchecked. Often times, a wideband air/fuel gauge can also monitor boost levels simultaneously, thus you can monitor two important forced induction related parameters on the one gauge.

Multi-Gauge: Since there are so many parameters worth monitoring on your F150, an electronic multi-gauge is an excellent alternative to a stack of external gauges. Using the OBDII port, multi-gauges can show any parameter the ECU is capable of monitoring, in real time. They are manufactured in various sizes, with some being as small and streamlined to fit into an A/C vent whereas others feature a multi-inch touch screen.

There are plenty of places in the cab of any F150 to mount a few extra gauges without disrupting the natural flow of the interior. Prime space includes:

A-pillar mount: There are many mounts available that install on the A-pillar found to the left of the driver seat. Available as individual mounts, dual mounts, or triple mounts, placing smaller 2-1/16” gauges on the A-pillar maintains a smooth aesthetic, but is also extremely easy to glance at.

Dash mount: Placing gauges across the top of the dash (over the media console) is another popular mounting area. Also easy to look at, dash mounted gauges aren’t confined to 2-1/16” sized gauges as there is plenty of space to go bigger.

Vent mount: The latest trend with gauge manufacturers happens to be sizing them in a specific way that they can fit neatly into one of the A/C vents. This provides the most streamlined look possible at the expense of a slight deterioration in cabin temperature control (however, some vent gauge systems claim to only block part of the vent and the unblocked portion is still fully functional). However, being located in a vent means you will need to glance down in order to read the gauge, as they are a bit below eye height.