Radio Install in 3520 with cab

   / Radio Install in 3520 with cab #1  
Joined
Apr 6, 2007
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This is some information for those people who don't have a radio in their cab tractor or for those who want to upgrade. You SHOULD be able to install a radio by just taking off the plastic frame in the ceiling of the cab--just 2 Allen head bolts to take out. The center of the frame just pops out. Again, you SHOULD be able to just put your radio in that hole. Note that I said SHOULD! More on this later. Take a razor blade or sharp knife to cut out the thin foam that covers the hole in the liner--keep in mind that one side of that stuff is very sticky and if you fold it back on itself, you can't get it to come apart. If you have small enough hands, you should be able to reach into the hole and feel around for the antenna cable and the wiring harness plug. If you look into the hole, you will also see a bronze colored bracket that the radio butts up against. The antenna cable is taped down (looped) so you will have to remove the tape to get enough slack in it to plug into the radio--the antenna cable is short so be prepared so you don't pull it too hard and take the coating off by scratching it on something sharp up there in the attic. The JD wiring harness has a plug on it with maybe 10 wires coming out the back.

Your radio should also have a plug with it with somewhere around the same number of wires coming out. Make your life easier by buying an adapter. The one I got was for a recent (after about 1986) Volkswagen car and it fits right into the JD plug. Do yourself a favor and make good connections between the wiring harness that came with your radio and the VW one you just bought because if you are anything like me, you will be putting the radio in the hole a dozen times and then taking it back out so a quick snap in, snap out of wiring harnesses is ideal. Using electrical tape around twisted wires is just not worth the effort of the $15 it costs for the VW plug. Besides that, you can make all those connections on the workbench instead of over your head. Do not get excited if the number of wires from your radio don't match the number of wires in the tractor. There will be a bunch of wires you don't need--like rear speaker wires (the tractor has only 2 speakers) or raising the antenna wires for example. Most radios have color coded wires that match up to the same color coding on the JD side. On top of that, printed on the radio instructions or right on the radio itself, there will be a description of what each colored wire represents. Tape up any wires not used so they can't short out.

Most radios that I have purchased come in two parts. The part that I call a can--an empty rectangular cage with both ends gone goes into the hole in the cab first. This can has tabs that you bend down to hold the can in the ceiling and the tabs are spaced so that you can choose ones that match the thickness of the ceiling material. Once you get this in, you feed the wires and the antenna through the center of this can. Take your radio and hold it up there while you plug in the antenna and your wiring harness. Then you should be able to slide the radio into the can until you hear it click into place and you won't be able to remove it. All this of course is in theory. Now comes reality.

In my case, the radio seemed to be about an inch too deep to fit into the hole properly. After darned near wearing out the antenna connection and the wiring harness by taking it apart so many times, I decided there was only one way to do this and still have some hair left on my head. Take the roof off. Yes, I know, drastic as it sounds, it is no big deal! Get out your metric wrenches cause you will need them. There are 13 nuts to take off before the green fiberglass roof can be lifted off. There are 3 under each door--you have to have the doors open to remove them. There are 3 more at the front windshield. And there are 4 at the back--you must remove the cab air filter box to find two of them. The other two are behind the yellow signal lights. If you remove the inside bolt at the bottom of the light, and loosen the bolt at the outside of the light, you can swing the light out of the way to get at the other two roof nuts without totally removing the lights. Again, in my case, the fiberglass roof was stuck down a bit, not a lot, but it is difficult to get your thumbs under the fiberglass to pry up, so some careful (VERY CAREFULL) forcing up will cause it to finally come loose. Now get some help and two step ladders. (NO, one person can NOT do it alone!) One person on each side of the cab and lift the roof STRAIGHT UP till it clears all the bolts. Keep in mind that those 13 bolts that you took the nuts off are now looking down on the top of your air conditioning system and a whole bunch of other wires so don't just drag it off or you will wish you didn't when those bolts put a hole in the AC radiator. Now finally, you can see where your radio needs to go. I put the can in the hole first and did not bend over any tabs until I had the radio in, the plastic cover that snaps into the face of the radio on, and the JD plastic frame you removed way back in step one, and the radio attached to that bronze angle bracket referred to previously. Finally, when all that was done, then I bent over the appropriate tabs to keep it in place. Re-assembly is just the reverse and shouldn't be a problem. Check to make sure that the foam seal around the outside of the roof is all in place and continuous so that you are not air conditioning the outside of your cab instead of the inside. Think about it--the space between the green fiberglass roof and the ceiling of the cab is being used as duct work to force cool or hot air into the ceiling vents, so any holes in the seal means the air is leaking to the outside of the cab.

Was it worth it? To be honest, when I first was having so much trouble getting the radio in without the roof off, I thought about taking the radio back to the store for my money back. But after dreading the thought of taking the roof off, it really was a piece of cake. If I was going to do it again, I wouldn't think twice about taking the roof off right away--it is just a whole bunch easier than fighting it from inside the cab. For those who want to upgrade the speakers while you are at it, sorry, I can't help you because I didn't do it.
 
 
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