Some factors for this: dashboard design, steering wheel design, and IR signals project isn't a example of efficiency.
I'm from Brazil and found this tip on Amazon.com reviews and take some photos to explain for you. It works fine with me - I have two units. Second part teachs how to fix the little lock of base. This last part I broke my head even obtain sucess and I will explain for you too. Don't forget: It will annul warranty of unit. (Check battery before do it).
It works with sr-100, sr-90, sr-70 and avic model...maybe others too.
Let's go and sorry my very bad english.
Step 1: Open Unit
Put screwdriver on slit (under pionner logo).
Carefully make movements such red arrows. It's safe, I have two units and both open easy with the same method.
It will disassemble in two parts.
Unit has 2 circuit board, look next photo.
Step 2: Components
Observe that leds are completely covered on unit box. This box has a thick and very black plastic. It weakens IR signal.
Remember your Tv, radio and receiver remotes units: Leds are external ou semi-external or it stay behind a slim plastic.
Note: I used rubber gloves to prevent oxidation and electrostatics it's not 100% necessary. I bought on drugstore - $ 1.00.
Step 3: LEDs
Point leds to dashboard will increase IR signal. But, wait, it isn't the unique step.
If you understand all, carefully bend leds to photo position. You do not need tools for this.
You can use plier, but care to do not damage leds.
Step 4: Drill
Conform previous explanation: This box had a thick and very black plastic and this is bad to IR signal.
You will need:
- Drill driver to make holes.
- drill (1/8 - more or less: 4,5 mm).
If you don't feel safe to make holes with second circuit board on unit, you can remove it. Liberate four little screws to remove it. Look photo: Two red circles shows two little screws. The other two screws are close them.
Step 5: Holes
These holes will be on the same line and height of leds when unit is closed.
Make a scratch with Screwdriver or liquid paper to mark exact place of holes.
Step 6: Holes
Be careful with drill driver, surface of unit is very curve, and a slip can make a big scratch.
Step 7: Board
If necessary, revise leds position. They are pointing to holes?! If no, bend carefully again.
IMPORTANT: Don't force leds, they will not penetrate on the holes. Only will point to them.
Step 8: Closing Unit
You can see unit ready on this photo with two holes and two leds inside pointing through.
Step 9: Work Place
Step 10: Under Steering Wheel
Step 11: IF LITTLE LOCK OF BASE IS FAILING OR FELL DOWN - LEARN TO FIX IT.
Look red arrow: A little of melted plastic is the unique thing to secure it.
After some years, this melted plastic can brake and the little lock fault or unit do not fasten appropriately on the steering wheel.
Step 12: Base Without the Little Lock
To fix it, you will need:
- The famous glue named araldite
- Hot glue.
Step 13: Araldite
1 - Put a little of araldite on base button (look photo - yellow part is araldite).
2 - Mount the little lock inserting the little lock hole on base button.
3 - To conclude this step, after little lock mounted, put again a little of araldite above it - Look photo 2 - On the corner. It normally needs 24 hours to dry completely. After 24 hours, don't try to use yet.
Step 14: Finally
This step needs glue very hot to work well.
Make a line of hot glue crossing little lock (on the middle) - Look photo. This hot glue line will work as pressure, in other words: go and back movement.
I tried 4 or 5 times to works fine - some times, hot glue fell down or I put a lot of glue and the little lock stayed very hard. Araldite only worked better on second time too. Don't desist, you can do it.