GOTL Code-3 MX7000 Lightbar

Of all the lightbars I’ve used in my law enforcement career, my favorite was the Code 3 MX7000 lightbar I used as a Geneva on the Lake police officer. I’ve collected vintage emergency lighting and sirens for many years, and one of my goals has been to have one of every lightbar that I’ve used.

Last summer I found someone selling an old MX7000 lightbar and purchased it with the intentions to rebuild it as a tribute using the specs of that old GOTL lightbar.

The all blue lightbar was a bit rough looking and was equipped with intersection sweeps and a rear Arrowstik, but there was just a diamond mirror under the clear center section instead of a rotator. For the purpose of this build, I would be removing the Arrowstik and replacing the entire center section with a speaker and grill.

Several years ago, I was the winning bidder for a large group of MX7000 lightbars on GovDeals. I sold all but a couple I kept for myself and salvaged a few for spare parts, so I had all of the parts that I needed to rebuild this lightbar.

I stripped this lightbar all the way down to the aluminum frame before cleaning everything and reassembling it. I had a shiny speaker cover that I was really reluctant to paint, but I needed it for this build, so I finally gave it and painted it satin black. The original harness had been cut off just below the lightbar, and my plan is to display this on a shelf and run the wires to a Code 3 V-Con siren mounted to the bottom of the shelf, so I replaced the harness with a longer harness I had in my spare parts.

All in all, I’m really happy with the way it turned out, and it looks great on my shelf. Below if a photo from 1989 of the original lightbar on the Geneva on the Lake 1986 Chevy Caprice 9C1 cruiser. For more information on that car check out: GOTL Police Chevy Caprice 9C1

Recreating the MX7000 Lightbar From This Cruiser

Wet Sanding

I washed the lightbar with Dawn dish detergent and then wet sanded the lenses with 800, 1000, 1500, and then 2500 grit paper. In the picture below I wet sanded and polished just the corner of a lens so you can get a better look at the before and after.

There’s a lot of pollution and tree pollen that gets stuck to these lenses over the years. I wet sand, wipe it clean, and if I’m still getting a yellowish-brown residue on my sponge or sandpaper, I keep sanding. Don’t ‘block sand’ it in a straight line. You end up seeing lines in it when you polish it. You have to wet sand it in a small circular motion.

Once the residue is white, I know that I’ve removed enough.

After wet sanding I polished the bar with Meguiars PlastX and a polishing pad but ended up switching to a wool polishing pad and a Meguiars polishing compound. The lens looks a lot better now. It’s not perfect, but I don’t want the bar to look like it’s brand new and never been used. The wear and tear are the story of its life, and I like for it to look like it has a story.

Disassembling The Lightbar

I removed the black shields that cover the lower level and then removed the (4) screws that hold the rotator tray in place. There’s to wire connects underneath that you can unplug after you unscrew it and tip it over. Next was unplugging the Arrowstik and removing the (2) screws that hold the circuit board in place. The Arrowstik in the center section slides into a groove in the lower tray and isn’t held by screws.

With the rotators and Arrowstik out, I was able to unplug all of the lights in the lower tray and then remove the lights. To remove the lower trays, you have to remove the lower center tray fist. It sits on top of a lit on the inside edge of the lower trays. After removing the lower trays, I removed the wiring harness and then cleaned the aluminum frame and lower clear trays before starting reassembly.

Reassembling The Lightbar

The original harness was cut off just below the bar and I want to connect this lightbar to a Code 3 V-Con siren mounted under the lightbar on a shelf, so I installed a longer MX7000 harness that I had in my spare MX7000 parts. After mounting the harness, I installed the lower clear trays, and the Code 3 flasher. Then I installed all of the lighting in the lower trays and wired them up. With all of the lights in place, I add the red and blue filters and did a final test to make sure everything worked before moving to the speaker installation.

Installing A Siren Speaker

The original MX7000 on the Geneva on the Lake 1986 Chevy Caprice 9C1 police car had a siren in the lightbar. I would have to install this speaker deck that not only gives the speaker a place to sit, but it also holds the speaker cover and covers the lightbar frame to keep water out of it. You can see the metallic tape on the back side of it. You may think someone added that, but this is how it came from Code 3 PSE.

Below are the instructions that Code 3 provides for installing a siren speaker:

(Single Speaker Installation in 43″, 47″, 52″ & 58″ Light bars) Speaker Installation is advised at this point while the speaker section is easily accessible.
To install a speaker, first remove the two (2) hex head screws, (4 screws on 58 1/4″ bars) from the bottom of the perforated side of the speaker cover.
The cover is hinged at the back–pull the front of the cover up and over the lenses to remove it.

Figure 1 shows the speaker cover opened and location holes for installing a Code 3 “LP” speaker. If other than a Code 3 “LP” speaker is used, two possibilities exist for speaker installation. An “LPSPKR” conversion kit is available from the factory to mount an existing speaker in an MX7000TM. Otherwise, holes must be drilled for installation. The center speaker deck is 1/8″ thick aluminum and may be drilled almost anywhere. Before drilling, however, it is imperative to remove the speaker deck so as not to damage any components below. All holes in this area not used must be sealed with some type of water-resistant caulking so that components below are protected from the elements. Re-install the speaker deck, then mount the speaker and connect the leads to the terminal block. Non “LP” speaker bells must be trimmed to match the speaker cover contour. Replace the cover.

(Code 3 “LP” Speaker)

Since this lightbar was introduced, manufacturers have come up with low profile siren speakers. I didn’t have an “LP” speaker and didn’t want to cut up a good speaker bell, so I purchased a 100-watt ‘Slim Speaker’ from LED Outfitters for $60. I replaced the mounting bracket that came with it for a pair of L-brackets so that I could mount the speaker flush on the speaker deck so it would clear the speaker cover. I drilled larger mounting holes and used bolts to secure it because the weight and design would apply to much leverage and force for the Code 3 screws to hold. This setup fit perfectly with no other modifications. I did have to run speaker wire into the lightbar because there weren’t any unused wires available in the Code 3 harness. I will probably cover the original harness and speaker wire with a heat shrink sleeve to neaten it up.

The lightbar is finished and looking beautiful!!

Video