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My 85 currently has a single DIN radio with adapter in it that came with the purchase. It works great and came with an aux input, but just doesn't look right. A few weeks ago, I pulled a 1.5 DIN from a 2001 (I think) Grand Prix after seeing some recommendations here on TGO. Thankfully, when I got it home and bench tested it with my power supply and extra speakers, it worked! Only thing to do next was to modify it so it could play music from my phone. Not a completely fair picture as the center console is not installed and faceplate is off, but the general idea is there. Just not what I am looking for in a radio.
First step I did was to disassemble and follow instructions here on TGO about patching an aux input directly into the cassette feed. I took apart the entire unit because I wanted to get a reading on the chip that handles the cassette sound and confirm the wires were correct (have lots of spare time on my hands right now!). Sure enough, the right and left channels are the first and third wires feeding into one of the connectors. Knowing that I would be eventually using a bluetooth module, I did not bother with a five-pin audio jack as the bluetooth would be automatically feeding as soon as the cassette is inserted into the player. Using a spare 3-pin aux jack and a broken USB cable, I connected the wires as shown:
The aux jack worked great and I considered leaving it as such with a long male-to-male cord running out from under the dash. After much thought, I decided to keep going and search for a bluetooth adapter that I could wire in. That turned into a farce of issues but ended up right at the end. A couple of months ago, I purchased through aliexpress three bluetooth boards for another project (retro boombox with bluetooth functionality). With international shipping pretty much shut down, those items are evidently still waiting in the overseas warehouse. Figuring they would NEVER show up, I started looking for US options. Turns out local options are really limited. I finally selected a USB audio dongle on Amazon that had halfway decent reviews. Wasn't excited about using a dongle as that meant I would need to step down power from 12V to 5V, so I hacked apart a cigarette USB adapter. For the first time ever, my order from Amazon disappeared into a black hole, never to be seen. Took almost an entire week to get the order closed and a refund issued. Aaargh!
The delay turned out to be fortuitous. I dug around farther and found a module on Amazon that is perfect for this application. It is a DROK audio receiver board that handles 5V - 24V. I wouldn't want to test the upper limits, but I did power it up to 14.8 volts and no blue-smoke appeared. DROK audio receiver from Amazon
This is a pretty slick board with separate power inputs, plus you can access the audio outputs through either a 3.5mm audio jack or a three-pin header with the mating header pin connector and harness included. I opted to use the 3.5mm jack as I had tested and knew I was going to need a ground loop isolator. Adding in the module took only a bit more work. I wanted it to power up only when a cassette was inserted into the player, so I tapped into the power feed of the cassette motor. I first tried to run the unit with the power lead disconnected from the motor, but the player didn't like that at all. It can tell when the tape is not turning so automatically spits it out. Used the same ground as the aux plug hoping to minimize noise, but there was still a slight amount of feedback through the speaker. +12V to bluetooth module supplied by power going to cassette drive motor. Turns BT on when cassette inserted into player. Ground connection. This one was tough to solder in. Took scraping off the coating and getting down to bare copper and solder, plus lots of heat to get the factory solder to bond.
Since I was using the aux jack, it was then just a matter of plugging in the ground loop isolator and mounting the BT module. I put the unit back together first to see where would be a good spot to mount inside the unit. Found lots of space on the side of the cassette player housing, so took everything apart again and drilled a couple of screws to mount the board to the chassis. The board is completely coated on the backside, so no chance to bridge connections against the metal chassis. Mounted securely to the cassette player chassis
All the needed to be done then was tuck everything into place and power it up for the final test...
Everything works great. Range for the BT is not great, probably just a couple of meters. I thought that might be the result, since it is mounted inside a metal case, which would restrict range significantly. However, since my phone will almost certainly be within a couple of feet of the unit while driving in the car, I figured that is a sacrifice I could live with. I did not want to mount the unit outside the case as I think it could cause issues when sliding into the radio pod.
Here is the unit all reassembled and powered up (although I did forget to put the power/volume **** on for the pic - it was getting cleaned). Next step will be to remove the radio pod and make the minor modifications required to cope with the different radio harness.
I like the idea of activating it with the cassette. Just gives it an extra period correct touch. I’m looking to do this to an eq radio I picked up for my 86. I bought a 4th gen radio with this mod already done to it because I couldn’t find one sold in the 3rd gen style. The 4th gen radio has the cassette hole plugged with an on/off button to switch between bluetooth and the radio. Thanks for the info, I’ll definitely use this when I start on my radio!
Glad I could help! Only fair, as your videos have been a HUGE help and inspiration on my 85 - from the quickjacks to even this radio project. The nice thing on your BT radio is there would be zero noise from the cassette deck as I am assuming it has been completely removed.
This is pretty easy to do, with the right components. The hardest part was finding the BT module, so I am glad this post can help direct!
I didnt mention it much in the first post, but the inline ground loop isolator is a must have to cut down the noise. I used a MPOW isolator and happy with results.
Glad I could help! Only fair, as your videos have been a HUGE help and inspiration on my 85 - from the quickjacks to even this radio project. The nice thing on your BT radio is there would be zero noise from the cassette deck as I am assuming it has been completely removed.
This is pretty easy to do, with the right components. The hardest part was finding the BT module, so I am glad this post can help direct!
I didnt mention it much in the first post, but the inline ground loop isolator is a must have to cut down the noise. I used a MPOW isolator and happy with results.
Can't wait for more of you TA videos!
Thanks, I’m probably gonna do this mod to the trans am’s radio first being I have the 4th gen in the Camaro for now. Glad I could help as well, and hope to start work on the trans am soon. Just need to finish tying up loose ends on the Camaro so I can get it tuned first!
Radio is finally installed! Worked yesterday on clearancing the support that is bolted into the back of the radio pod. A lot of influence came from LAFireboyd's information on the post here. He put up some great pictures showing where to clearance the rear of the pod to allow for smooth installation of a later model 1.5 DIN unit. Possibly because my unit is has a cassette deck versus a CD player, I had to do a bit more removal of the plastic. Based on both sets of pictures, the cassette units must be deeper in depth than CD units. When inserted into the pod, I still needed about 0.25" to get the unit to sit flush - the rear of the radio was hitting the back of the radio structure. I am naturally reluctant to carve into original pieces, so I spent a day deliberating on what to do. I decided to remove the material I needed but use ABS cement to put it back in place and keep strength in the unit. Here are some pictures: My car had previously been stripped of all OEM parts, so I needed to modify the Grand Prix mounting brackets to fit the mounting holes in the pod. The sharpie marks represent where I started to cut. With the radio sitting as far back as it could in the pod, it was resting on the middle support structure. Used a utility blade to mark where it was interfering.
Because the OEM radio is so heavy compared to the original unit I had in place, I wanted to make sure that the support structure pictured above would continue to support the weight of the unit. I believe that is the reason the lower holes were all blown out on the face of my radio pod initially - which I had to reconstruct from ABS. The front of the radio pod just isn't designed to support the entire weight of an OEM head unit. My plan was to shave as little material off the back as possible so the cutout area could act as a major weight supporter of the radio.
For whatever reason, I rushed from test fitting on the bench to installing into the car without taking in-process pictures. See the link above for the detail LAFireBoyd provided in his pics for cutting out material for the radio harness. I started as small as possible and kept shaving away until everything fit smoothly.
Radio pod reinstalled. Closeup showing the clearancing on the rear support plus areas removed to allow the plug for the Grand Prix radio to clear the support. Also note the area ground away by the hole - one ear on the plug was interfering with the larger ring. Finally, the conduit cover I put over the wires had to be removed and the bundle instead was taped. The larger conduit cover prevented the wire harness from sliding back into the recessed area.
Finally, here are pics of the head unit installed. I'm pleased with the results, although I found after installation that the #2 button on the radio does not work and a light appears to be burnt out above the treble slider. It was a bit of a challenge to fit everything in, likely thanks to my extended wiring harness - I had to solder the original car harness to the radio harness and left myself plenty of wire. Regardless, final result better matches the overall look of the car, and the bluetooth works great! Lots of small adjustments and grinding around the mounting flanges to get the unit to sit properly in the radio pod. I probably could have worked a bit more to raise the left side of the radio up about 1/16", but decided to call it good as everything looked ok with the faceplate installed. Had gotten tired of using my Dremel to mill out the holes bit by bit. Final install with the faceplate on and the radio all lit up for show.
Cost breakdown of the project (from my best recollection):
Radio from local pick-a-part = $15
DROK bluetooth module on Amazon = $14
Ground Fault Isolator = $11
So around $40, depending on the ability to find a radio at a good price. I'd estimate a total of six hours between modifying the radio and the radio pod support, but I never work fast. After doing one, I would think I could have the BT module in the unit and have the radio reassembled within an hour. But without the head-scratching, it becomes less fun!
Finally, here are pics of the head unit installed. I'm pleased with the results, although I found after installation that the #2 button on the radio does not work and a light appears to be burnt out above the treble slider. It was a bit of a challenge to fit everything in, likely thanks to my extended wiring harness - I had to solder the original car harness to the radio harness and left myself plenty of wire. Regardless, final result better matches the overall look of the car, and the bluetooth works great! Lots of small adjustments and grinding around the mounting flanges to get the unit to sit properly in the radio pod. I probably could have worked a bit more to raise the left side of the radio up about 1/16", but decided to call it good as everything looked ok with the faceplate installed. Had gotten tired of using my Dremel to mill out the holes bit by bit. Final install with the faceplate on and the radio all lit up for show.
Cost breakdown of the project (from my best recollection):
Radio from local pick-a-part = $15
DROK bluetooth module on Amazon = $14
Ground Fault Isolator = $11
So around $40, depending on the ability to find a radio at a good price. I'd estimate a total of six hours between modifying the radio and the radio pod support, but I never work fast. After doing one, I would think I could have the BT module in the unit and have the radio reassembled within an hour. But without the head-scratching, it becomes less fun!
thainglo Which Ground Fault Isolator did you end up using?
Diagram looks close, hard to see everyone the screen. If you can send a clearer image, or a link, I can check it out. Will need to brush the cobwebs off the old noodle!
Diagram looks close, hard to see everyone the screen. If you can send a clearer image, or a link, I can check it out. Will need to brush the cobwebs off the old noodle!
Interesting that the same one I've got in my Amazon cart
Diagram looks close, hard to see everyone the screen. If you can send a clearer image, or a link, I can check it out. Will need to brush the cobwebs off the old noodle!
06-15-2020, 10:24 AM
