Electrical Wiring for Boost Gauge

Hello peeps, ran into an issue trying to wire a TRD boost gauge electrically. So I used some T-Tap wire connectors to tap into the ECT button wiring harness. I have attached two pictures just for reference. I connected -Negative black wire from the boost gauge to the White/Green wire on the harness. I connected the +Positive wire to the Green/Red strip wire on the harness. When I turned on the parking lights the gauge lit up. I used the dimmer switch to dim the interior dash lights and it worked. Shortly after, the 10A fuse under the hood for the TAIL blew out. I replaced the fuse with another 10A and said what the heck maybe its the -Negative wire I connected to the White/Green wire on the harness. I connected the -Negative wire from the gauge to a good ground under the dash. I kept the +Positive wire from the boost gauge connected to the Green/Red wire from the harness which has 12v when I turning on the parking lights. The lights on the gauge turned on shortly and the 10A fuse blew again. What am I doing wrong? Could it be because I changed the normal bulbs on the gauge to LEDs? How have you guys wired your gauges? Thank you all for your help

 

Your wiring sounds correct according to my diagrams.
I know leds are directional, but you say they light up and then the fuse blows?

Does the fuse blow with the lights not hooked up? (Pull the fuse for the lights in the gauge)
If not, switch back to the normal bulbs and try again.

The Tail fuse powers a bunch of stuff. But I wouldn’t think adding 2 small leds would cause the problem?
What are the watts on the leds?

 

Yup at one point I had to turn the LEDs a full 180 degree to get them to turn on. Once they are on for a few seconds, it blows the 10A TAIL fuse. Only happens when the gauge is connected to the harness. Have never had a fuse go out on me till now.

LED specs say Operating Voltage: 12V and Output: 0.3 Watts

 

Are you confident you don't have anything shorting in the Y you have covered by your heat shrink tubing? What size fuse are you running in line?

 

Im pretty sure it is good. I will remove it and double check this Thursday since I will be parking the truck for a few days. So the way I originally installed the wiring to the first time (as pictured) is correct. At this point I don't really care if the LEDs dim or not. Just want it to work lol.

 

The EWD agrees that green with red stripe is the power, and the white with green stripe is the ground. Changing from incandescent to LED should lower the power draw, not increase it. I'd be looking for a short either in the new section of wiring you've added, or around the taps you added to the existing wiring. Do you have a picture of the taps you added as installed?

 

You can see them here. Wish I had a better picture. They are meant for 22-18AWG wire.

 

You could always run a relay if you just want the gauge backlight to turn on with the cluster lights. Let the coil be activated with the wire you’re tapping into.

 

Thank you. I would like for them to come on with the dash lights, like normal. Just don't care if they dim or not. I thought my ground was the issue. But even after grounding to good metal under the dash, my TAIL fuse still goes out. Im going to have to double check the wiring on the gauge where the wiring for the two bulbs meet up. Im sure I double checked, but I will check a third time this Thursday.

 

Do you have anything showing the wire that connects to the taps? And possibly a picture of everything connected at the ECT switch plug?

 

I don't. I wish I would have taken pictures of it. It didn't cross my mind. I will duplicate my work Thursday and post pics/updates. Thank you very much. Hopefully your available to help. Thanks

 

I'd tap into a positive wire for the illumination circuit, and use that wire to trigger a coil on a relay to send power.

Though this should not be necessary. I wired my AFR and boost gauge backlight to the rheostat.

 

Do you recall if the +Positive color wire from the rheostat is the Green/Red stripe? The rheostat would be the dimmer knob correct? Sorry for the noob response. Electric stuff is not my strong suit. You also lost me with the coil and relay haha.

 

I don't quite recall, it was so long ago. You can find out which one dims with the rheostat by using a voltmeter, though I don't recommend using a dimming wire since LED gauges rarely support linear dimming like incandescent does.

Just find a wire that's constant 12v when the headlights are on.

 

The Green/Red Stipe wire on the trucks harness is 12V when the lights are switched on. I ended wiring the +Positive wire from the gauge bulbs there. And my -Negative wire from the gauge I just ended up using good metal on under the dash. I ended up removing it from the White/Green Stipe wire on the harness. And even that way, it still made my TAIL fuse blow. Im kind of stuck. Ill have to pull the gauge out and triple check the wiring and make sure the bulb + and - wires aren't touching. I'm tempted to remove the fuse box I added. I doubt that is the issue.

 

Which leds did you use? Do they have built in current limiting resistors?

 

I purchased these below. I was reading through the item description and did not see anything about them having a limiting resistor. Unless it is written it some weird way. It does say 5050 Chip and it being energy efficient. Could it be the kind of LED?

D-Lumina 10 Pack T5 LED Bulb Dashboard Dash Light Red 1-SMD 5050 Chipsets Wedge 74 2721 37 17 73 PC74 LED Bulbs for Car Interior Gauge Cluster Instrument Panel Indicators Lights

https://www.amazon.com/dp/B08Z3276CG?ref=ppx_yo2ov_dt_b_product_details&th=1

 

If they’re a drop in replacement for a regular bulb then they’ve got built in resistors.

I’d probably start probing at your wiring on the gauge side with a meter in resistance mode, something sounds shorted. It is weird that it takes a few seconds to blow though.

 

Thank you. I think I am going to remove the wiring and start from scratch. Hoping its a mistake on my end. Maybe the bulb wires touching when I shrink wrapped them. I doubt it but I will restart everything

 

I think that’s a good move. It’s one of those things where if you didn’t fix it, it isn’t fixed, even if it mysteriously starts working. Much better to be sure.