Adding Led Eyes to the Mack Bulldog Hood Ornament




About: Im a Student at RPI in Troy NY. The best part of college is most definatley 'Spelunking' or dumpster diving for parts in the elctrical engineering dumpster.

The bulldog hood ornament is on just about every mack truck across the globe. I managed to get one, mount it on a jeep, and led lights for eyes. This instructable explains the led mounting procedure in non technical terms so your rig (or bike, kayak, dune buggy, etc) can have glowing eyes.

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Step 1: Procurement and Parts

Bulldog Procurement
the mack truck bulldog hood ornament is available for purchase on ebay or online
I purchased it 6 years ago at a tour of the mack truck factory for 30 dollars at the time. it might also be a good idea to find a big scrapyard and check.

i used 3mm (aka T1) bright led's check mouseror digikeyfor the brightest ones available for the color you choose. 5mm led's would be too big and look dorky. its also good to use clear led's so that when the eye's are off they look like part of the silver structure, not little red dots. resistors can be purchased at radioshack or along with the order.

Current Limiting Resistor
the resistor value you use is dependant on the led used and the power supply for your vehicle. for an led with a vd or forward voltage of 2.6 volts and an id or forward current of 20 milliamps (see datasheet image) and a vehicle with a 12v supply here's the procedure for determining the correct resistor value

(vehicle voltage - vd) = vdrop so:
12v-2.6v= 9.4V= vdrop

using R=(V/I) substitute values in place
R= 9.4V/ 20 ma = 9.4/ .02
so R = 470 ohms
the power dissipated across the resistor is calculated from P=IV
.02*9.4=.188 Watts , so a 1/4 watt resistor (common at radioshack or real electronic parts store) is ok to use. chances are a 1/2 watt resistor might be better suited as the resistor wont be able to dissipate much heat into epoxy.

Step 2: Drilling and Mounting

first off i placed the bulldog between 2 pieces of scrap pine wood to prevent scratches.

Its important to note that the back of the bulldog is hollow, probably for this purpose. I drilled out the eyes using a 1/8th drill bit and moved around until the led i chose could fit through snugly ( all the way through)

Step 3: Assembling the Circuit

this is really simple, the positive side of the led for each eye consists of the following shown below.

connect the ground to the frame of the bulldog via soldering with a hot soldering iron / solder gun. you have the choice of running either 2 or one switched lines up to the bulldog (if you want one to blink while turning or something) i used lamp cord for the automotive wiring

Step 4: Finishing Up the Lights

after soldering the led's and resistors wrap everything in electrical tape or heatshrink to isolate from the bulldog metal frame.

feed each one through and test each with a 9v battery (yes they probably still work at 9v too) or 12v supply.

to ensure that the led's stay in place i packed all the wiring inside the head with hot glue to temporally hold everything together. ensure that everything works, because the next step is to epoxy everything together. bang it with your fist, shake it make sure there is no flickering, nothing is more ghetto than a one eyed bulldog hood ornament.

also drill a hole for any power wiring (switched lines)

using a piece of broken bike tubing, i cut a piece that covers the bottom, remember to leave a spot for the power wiring

Step 5: Epoxy and Mount

fill empty area with epoxy and let dry

begin to mount the hood ornament. this requires drilling through your vehicle's hood (or your kayak) .

author's note
It took a few seconds to realize wow, im drilling through the hood. at the time i saved up and had the vehicle painted at an overnight re-spray warehouse in Brooklyn 4 months earlier (by a guy only known as big vinny) for this step its important to Take your time and not screw up.

drill through the hood at a predetermined point from the top, and file out the necessary distance so everything mounts properly, also drill for the switched power line.

mount everything and run the necessary switched power from a fused power line. make sure there is a fuse!

mount a switch and wham, your rig, kayak or jeep now has more testosterone.

Step 6: Vehicle Wire Harness and Switch

After completing the mounting, running a switched line to the hood is relatively simple. on most vehicles, the hood has reinforcement (see image, showing ribbed reinforcement thing under the hood)

There are already holes there from factory production, try to take advantage of them and use them for securing the switched line. keep in mind, separating the vehicle (ground) from the wire is very important!

Step 7: Final Product

Here's the results:

1 Person Made This Project!


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15 Discussions


11 years ago on Introduction

Correct me if I'm wrong but isn't it illegal in ALL states to have any red lights facing the front? Not that thats going to stop me from doing it ; ). One of the dogs came on a pickup i just bought.

5 replies

Reply 9 years ago on Introduction

well they say that its illegal because that it would signify a taillight, but i think that people will see 2 bright white headlights before they see 2 little red lights. especially through their car mirror. he should be ok, and unless you look closely in the mirror, its more of a close up decoration than a far away one.

Emperor Daneuncle_al_0

Reply 11 years ago on Introduction

wowsers, i didnt realize that. hmmmm..... well, i was thinking of modifying the led's to blink the left eye when turning left and the right one when turning right. what colors would look equally bad-ass as red led's on a red jeep. i guess white led's would look decent., orange is too close to red

wupmeEmperor Dane

Reply 10 years ago on Introduction

If you drive fast enough, the red will appear green because of the doppler effect, You just need a bit less then 15% lightspeed for that or 45.000 kilometers per second. You see, that red aint a problem if your car gots enough horses.

bigedvanEmperor Dane

Reply 10 years ago on Introduction

do you sell the mac dog with red led eyes if so let me know i would like to purchase.

uncle_al_0Emperor Dane

Reply 11 years ago on Introduction

Orange is perfectly fine to have on the front, look at your front blinkers for example, but i think you should be fine I'd just leave them until you get pulled over for it. At worst you would get an actual written warning.


11 years ago on Introduction

An anecdote. My grandfather used to say (living in Idaho) "It's cold enough to freeze the balls off a brass bulldog!". A few years back my dad acquired a Mack bulldog, so we sent it to the shop for a copper dip (brass dip isn't what you think it is) for Fathers' Day. They tried to sandblast the chrome off and found the sand blew through the pot metal the dog was made of... They acquired a replacement, bead blasted instead, dipped it in copper, and threw in a nice custom wood base (for our time and trouble). It sat on Dad's desk a year or so, then the house burned down... I like this, the led eyes are pretty cool. Forgive me for not wanting a Mack bulldog near my house ever again :)


11 years ago on Introduction

that would be stolen so fast, but wait. why not put a 50,000 volt charge through it. aka ( a flyback transformer) I'm stupid enough to know


11 years ago on Introduction

That's pretty cool. Definitely one I'll keep in mind for my next beater. If you want to get the noise down inside your jeep, try insulating the hood. There are specific materials (sort of like a blanket with a sticky back) that will really cut down on the noise at highway speeds. Check with your local auto supply house (or a junkyard) and pick some up. It's fireproof and all that good stuff.


xD thats awesome!!! when i get a car im gona do this with something lol but il have to weld it down cause someone from my school would probably try to jack it . thats a great instructable!

1 reply

thanks for the comment! the bulldog is held in place by a 5/8 inch threaded bolt, you probably don't need to weld it (it also is aluminum, so welding aluminum to steel would be a pain), but if your going to buy one, check your local scrap yard, they normally can order the parts or find it for you a lot cheaper than they would be available online. -Dane


11 years ago on Introduction

That's awesome, I love crazy stuff like this. Funny part was the 2nd to last picture. "On the hood." haha.