why you don’t buy electronics on online or ebay

Customer calls us on 7-9-17 tells us that he’s having issues with installing this double din radio into 2000 ford f150.. the oem harness has been cut and he’s trying to hard wire double din radio harness to cut radio harness..


So for us to help him we ask him to come to our shop.. he tell us once he get to us it came on yesterday but no sound but now it will not power up at all. We bust out our power probe test meter  we find out no power on the constant power wire or 12 volt ignition switched power wire. So we start checking fuses under the dash. We fine out the radio fuse is blown and we replace it and now we have constant power at the radio still can’t find why there is no 12 volt ignition switch power at the radio. So we run an 18 gauge red wire from the radio to the fuse panel and install a fuse connector on a fuse that only has power when the car is running.. Now we get constant power and 12 volt ignition switch power at the radio solder our connection and the radio powers up but we get no sound..  

Now this was a 6.5″ 2DIN TOUCH SCREEN Car Stereo DVD Player Bluetooth Radio no name ebay radio paid 109.00 free shipping 








after spending sometime checking to see if oem speakers work or even in the doors I come to the conclusion that the output from the radio is bad and customer needs to send back the radio to ebay seller for replacement warranty..

on the 7-16-2017 customer brings me a radio that he said that he just got it suppose to be a brand new replacement for the warranty radio .. Funny thing is when they email ebay seller they said keep the broken radio and we will ship you a new one. They didn’t even care to get old broken merchandise back.. so I unbox the new radio and plug it into the radio harness that we wired in the week before and radio comes on and power up function perfect expect still no sound. I start searching for info on the web for solutions or people that have this product with the same issues. can’t find anything after about an hour of trying to get sound out of the radio i accidently hit the eject button for the cd player and out comes a cd..

so now I tell the customer I’m guessing this was someone else warranty radio that for got to remove their cd before they sent it back to ebay seller. Now you have it and it no different from the first radio you got from ebay seller..NO SOUND

I take an old jvc single din radio i use for testing and use my power probe test meter to power up the jvc radio and cut a rear speaker wire off the harness of the ebay radio and connect the wires to the jvc radio turn it on and now we have sound coming out the trucks speakers but coming from my test radio. customer is pissed off royally ..

So now my customer has 2 broken double din radio from ebay with no sound non brand chinese crap radio and out $109.00 

This is why you don’t buy items online because seller can send you anything they want. you don’t have any way of getting in touch with most of them they may give you an email address but don’t respond or there number only goes to voice mail.

If the customer would have bought a radio from us .. It would have been new in sealed box and no issues.. with a labor warranty and a manufacture warranty from either kenwood,sony,jvc,power acoustik etc..


ebay radio pictures stay away from

coil springs vs coil-overs for lowering your car

When you have decided to lower your car (Not A Truck) you have a couple of choices to chose from .. Lowering Coil Springs or Coil-Overs. First you must decide what type of car your building or why you want to lower your car.

  1. Just want it lowered
  2. Building a street car
  3. Looking for better handling
  4. All out race car for specialized type of racing

what is a lowered coil spring. Coil spring is made from spring steel or carbon steel with a certain amount of coil revolution to make up the spring. Manufactures engineer coils to lower your car and keep the oem geometry for alignment reasons. When looking for a coil spring to lower your car you will notice 2 things.

  1. amount that lowers your right correctly
  2. the spring rate

not all cars can be lowered extreme amount some times you only get like almost an 1″  other cars can be lowered 2.5″ it’s all in the type of car you own. why is this because of the geometry of the suspension and the ability to be able to get your front or rear car aligned so you don’t go through tires every couple of months.

Now on to what the spring rate does say you took a oem spring and cut a couple of coils off the spring would be shorter but you would change the spring rate from the oem spring rate. You would get a higher spring rate on a cut coil spring and it would be stiffer not a bad thing and It would give you better handling to a point. SPRING RATE Spring Rate refers to the amount of weight it takes to compress a spring a certain distance.  The higher the spring rate, the stiffer the spring.

To figure out the Spring Rate you start by compressing the spring about 20% of the available distance of the spring and measure the height (Load Length 1) and the Load 1 in (lbs/inch) or (N/mm). Then compress the spring about 80% and measure the height (Load Length 2) and the Load 2

(Load 2 – Load 1)
Spring Rate = ——————————————-
(Load Length 1 – Load Length 2)

Most springs are fairly linear, which means you would get the same Spring Rate from the equation no matter which distances you would use, 20% and 80%, or 40% and 90%, or 10% and 30%.

Some springs are non-linear, which typically means the spring gets stiffer the more you compress it.  One way this can be done is by changing the coil spacing, so that coils start to touch each other as you compress it.  Another way common in racing is for the spring to compress and then encounter an additional spring.  This increases the spring rate because now you have 2 springs acting on the force.  Many times this additional spring is a rubber “bump stop”.


  1. Wire Diameter: When the diameter of the wire increases so does the Spring Rate. When the wire is thicker it becomes stronger and more difficult to deflect.
  2. Spring Diameter: When the diameter of the spring increases the Spring Rate decreases.
  3. The number of coils in the Spring: As the number of coils increase the spring rate decreases.





COIL-OVERS are a whole different type of part coil-overs are what most people would like because they have ton of adjustablility you can tune the suspension to your driving style. Coil-overs have the ability for you to adjust the ride height and they allow you to adjust the compression valving in the shock/strut  Not all coil-overs have the adjustment for rebound valving for the shock/strut and the pre-load can be adjusted hard core track racers.

What is pre-load on a coil over 

Preload is when the spring is compressed between its upper and lower perches on the strut body before the assembly is placed in the car. Basically its the length of the spring from top of spring perch to the bottom of the spring perch  on the strut body

A Simple Example With Preload

Let’s recreate the last example, but this time with a spring preloaded one inch. First what we are going to do is use Hooke’s Law to find the amount of restoring force (F) the 400lb/in (k) spring has with one inch of preload (x):

F = -kx

F = (-400lb/in)(-1in)

F = 400lb

What this F value tells us is that our preloaded spring is exerting 400 pounds of restoring force on it’s perches before it is even installed in the car. Now we need to install this preloaded coilover into the car. This is the point at which many people’s intuition leads them astray. When you factor in the weight of the car pressing down on the coilover you have to SUBTRACT its weight from the force already stored in the spring! So since our spring already had 400 pounds of force stored in it we subtract that amount of the 923 pound weight of the car:

938lb – 400lb = 523lb

Since our spring already had 400 pounds of force preloaded, the spring only has to absorb another 523 pounds (F). Let’s find how much additional compression will take place (x):

F = -kx

523lb = 400lb/in(x)

Solve for x:

x = -1.3in

So when we place the car’s 923 pounds on a spring preloaded one inch (400 pounds of stored force) it compresses the spring an additional 1.3 inches. Add this to the preload compression:

1.3in + 1in = 2.3in


Remember! Any force already stored in a spring acts against any force that is being added to it! This goes for all linear and progressive rate springs!

Compression valve adjustment

most all coil-overs will allow you to adjust the compression valving up to 27 different settings. Compression damping is the force experienced when the damper is being compressed. In the case of most vehicles, this is when the damper moves upwards relative to its mounting position; a good example is when you hit a bump at high speeds on the road. If there was no compression on your shocks or struts your tire would just move upwards along with the vehicle, losing contact with the ground. With compression, the tire will deflect over the bump allowing the damper to absorb the impact (hence the name- Shock Absorber) and the tire will extend back to its original state, all the while reducing the vehicle’s motion and not disturbing the comfort of you and your passengers.



Rebound valve adjustment

Rebound damping is the force that is experienced when a shock absorber returns from its compressed state to its original state. When a damper is in the process of rebound the spring goes from being compressed back to normal releasing all the tension from the compression. In some cases the ride feels bouncy or stiff because of the  spring rate and/or damping force settings not being compatible.  Keep in mind that if you have a damping force adjustable coil over the stiffer your settings are the slower the rebound. The softer your settings are the faster the rebound.


Now that you understand a little better what the difference is on lowered coil spring and coil-overs you can now chose which to buy. We sale brand like







One other thing before we go.When ever you lower your car make sure you get some kind of a alignment kit. Some coil-overs kits have the upper strut mounts that have camber adjustment .

If your just buying lowering coil springs you can get alignment bolts for camber adjustment and some cars have offset camber bushings. Even if your car get a 4 wheel alignment they have rear adjustable control arms and track bars to keep everything in align.

If your going to lower your car do it right the first time don’t just do what your wallet allows you to do. Save the money buy the right parts you don’t want to damage your car just because you didn’t want to pay to do it right!


2014 new advertising new business name

Well in the last few months of 2013 some of my family started asking me why I was only promoting window tinting when I offered other services like car audio,custom suspension ( lowering kits , lift kits , air bagged suspension kits). We also offer bed covers,performance programmers for trucks, welding and so much more . Well just so happens i decided to change my  dba .

I came up with Pro-Tech Services and why I know this was a good thing to do.A  few days before I began to do the name change .

I got a call from a seo marketing company that had told me how they could help me get a lot of business in 2014 buy using them to advertise my business online with seo marketing . What I liked out them is not only great price  They seamed honest and straight forward unlike the hundreds of other companies that have called me over the years.  We I told them I had to talked it over with my finance manager they told me to run with it.

Well this is the tools that this seo marketing company is providing us  2014 to keep up with google to be able to advertise my local listing.

They built us 2 twitter accounts for car audio and auto suspensions. 2 facebook pages on car audio and auto suspension and built us 2 websites for car audio and auto suspension.Since I built my own website back a few years ago to promote my business everything is linked to this main page so i don’t have to promote window tinting because that is mainly what my self built site is about.  They also get me first page ranking on google ,yahoo and bing and do all my seo optimizing for one low price.

Well you can find us  on twitter https://twitter.com/protechaudiocar and https://twitter.com/protechautosusp and my facebook pages are Pro-Tech-Car Audio in cape coral and Pro-Tech-Auto-Suspension in cape coral. Here are the links to our new custom website http://www.caraudiofortmyers.com http://www.autosuspensionfortmyers.com

So for now it just a waiting game to for all this advertising to get on the web and indexed on to the search engines so people can find it and my rankings come up to where i need to be. We are over half way there . call us anytime for question on anything we can do to help you . 22 years serving swfl