Information, Modification

2003 E-350 Transmission Temperature Gauge Installation

Towing without a temperature gauge is like playing Russian roulette with your transmission.  I know, that sounds harsh, but heat is the enemy, and unknowingly overheating your transmission can have catastrophic results.

The tow capability on this van is impressive, so I’m always amazed the low-cost options Ford decided to omit in its “HD Tow Package”, like extending mirrors, or a trans temp gauge.  On second thought, maybe it’s so that you can install one that actually works.  It was only after having my Suburbans 4L80E rebuilt that I discovered the factory standard temp gauge wasn’t reading correctly.  Live and learn…

Installation’s not difficult.  The hardest thing about the project is deciding on the style of gauge and mount location.

Here’s a handy visual aid that’ll give you an idea of what you can expect from high trans temps.


Parts list:

There’s a few different options for mounting, and the “A” pillar location was tempting, but I opted for the steering column because I thought having them in plain sight was too ostentatious- and too inviting for FSA folks who like to smash and grab stuff.  To start, you’ll want to locate the pedestal and temporarily mount it, to make sure it’s good visually, and doesn’t get in the way of anything.  Some cheap double-sided tape works well.  Right around ten o’clock on the column stalk works perfectly for the 2 1/16″ pedestal gauge in the Econoline van.  You could probably wire it up without tearing down the dashboard, but having everything exposed makes it a lot easier; besides, tear down isn’t very involved.

IMG_1177Pull the factory radio using some “U” style removal hoops. Yeah, you can shape some out of hanger wire, but good luck trying to find heavy duty wire hangers anymore.  The release tabs are pretty stiff, and the wire hanger I found was too wimpy.  Everything is “value engineered” to a fraction of a yuan, these days.

IMG_0002Remove the two bolts at the top of the instrument panel display.

IMG_0001Remove the headlamp knob by lifting up on the little tiny metal tab beneath the notch in the plastic knob.  It’ll slide straight off.  Then unscrew the plastic bezel.

Remove the metal knee cover.  It’s held on by (4) friction tabs at it’s corners.

IMG_0004At this point, it’s only friction tabs holding the dashboard fascia on.  You can pull it away enough to access the plugs behind the cigarette lighter and accessory outlet to disconnect.

IMG_0006Remove the (2) bolts holding the headlamp switch and connector.  Pull that out and splice into the instrument gauge illumination feed.  It’s the connector at the “I” location (light blue with red stripe).  This connects your new temp gauge backlighting to your IP dimmer knob.IMG_1158Pull the cover off at the hood release lever.  There’s a little cover panel directly behind the hood lever that pops off, then you can pull the whole cover; it’s held on by (2) friction tabs.  You can then access a convenient ground location right on the body panel.  Connect (2) ground wires to it using ring connectors.

Plug-in your fuse block tap adapter.  I used the instrument cluster slot with a 10A fuse.

  Next, you’ll get under the van and mount the sensor into the transmission test port.  Don’t worry about leakage when you remove it, there should only be a few drops.  Put some teflon tape on the threads and screw in the sensor.  I ran the sensor wire along the underside of the body pan, over to the driver foot well, where I routed the wire up thru the emergency brake cable hole, and up behind the trim panel we removed at the hood release.  Much easier than negotiating the firewall.

IMG_1159Bundle the wires and feed them up above the steering column assembly right at the hazard flasher switch.

Check your feeds with a voltmeter.  I found the instrument dimmer feed would read between 6-12v.

Permanently mount the pedestal.

Connect to the temperature gauge.  My model required soldering the backlight ground and 12v.  The sensor, ground and 12v feed for the gauge itself used ring connectors.

img_1166Fit the cup over the gauge, and tighten down in the pedestal ring.  Reinstall all the trim pieces.

You’re done!


8 thoughts on “2003 E-350 Transmission Temperature Gauge Installation

    1. Thank you! We had some technical difficulties this past month, but I think we’ve got it all worked out. Hope it didn’t put you off. Thanks for visiting!

  1. Looks really nice! For anyone else looking to add a tranny temp sensor, another way to do it is just by a Scanguage 2 which plugs into the OBD2 port and reads off the built-in transmission temp sensor. Takes about 10 minutes to install and program it.

    1. Thanks! Yeah, I’ve heard good things about that OBD scanner. The stock sensor is near the torque converter, I think? It would be interesting to see the difference in temps under load.

Leave a Reply