I can put a hot battery in my rv, and it will usually crank. But, I have a small surface mounted compass on my dashboard, and when I turn on my ignition to crank, that compass goes crazy, spinning forward,backwards, all around, and want stop, and this compass has no electrical going to it, it's just sitting up there, and also, several of my gauges on my instrument read incorrectly. I'm looking for a starting point to try to troubleshoot this problem, and don't know where to start. I had the alternator tested, and it tested to be good. Please give me some help..........thanks RANDY MORGAN
The Alternator only comes into play AFTER the vehicle is running so I would bench test the starter for excessive starter draw. If the starter tests good I would change out the Solenoid. That may explain the guages reading incorrectly. As to the compass, possibly a shorted wire near there could cause it to spin. Try relocating it.
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If there are no markings, the only way to determine what value they are is to unsolder them and test them. Actually surface mount components don't go bad that often, most likely capacitors, maybe some diodes. They usually do have numbers on them, maybe soldered down side up.
Electrical interference has been around for AM receivers of which the CB radio is one, except if you use SSB. If you are using it in a house the only thing you can really do is install an AC line filter and/or move the antenna to a location as far as possible from the source of the interference.. Take an AM portable radio to locate the source. If you can't eliminate the source inteference then you may have to live with it.
If the radio is in a vehicle then the source is usually from the ignition system or the 12DC feed. Radio Shack sells surpressors. The usual cure is to install resistance spark plugs and make sure the hood and firewall are properly grounded. This is usually done with a heavy braided wire connecting the hood to the body and the body to the firewall. If you have a mounted antenna, move it as far away from the source as possible. The source can be found using a sensitive portable AM radio. If the antenna is mounted in the rear ,trunk or bumper, make sure you use a heavy braided wire to ground the muffler by the motor and where the pipe ends before the tailpipe.
I did this in the 60's and it was a real problem then because of the use of a mechanical distributor and the lack of unibody construction.
You have a high-power radio that will put out over 200 watts RF power. You're drawing too much amperage from your car's electrical system, causing it to shut things off. First try a new and higher CCA rated battery. After that, you might need a bigger alternator. 200 watts is usually not a problem unless you have a little car built to use as little resources as possible to increase mileage.
CB radios are AM radios operating in the 27Mhz band and are prone to noise even in home installation (though admittedly not as much). A signal on the meter that causes the indicator to move up to as much as 1/4 of the scale is actually pretty good for a mobile installation with the engine running. There are ways to minimize the noise, but none will eliminate it. Here are suggestions - in no particular order:
1) A well grounded antenna. Since you've got metal to metal contact with yours it shouldn't be a problem - the magnetic mounts are more prone to interference and noise that yours.
2) Locate the antenna on a large, flat, horizontal, metal surface. Mobile installs are always a compromise - but the more of these you can incorporate, the better the reception & transmission will be. There will still be noise - but when you receive better signals the "S/N" or "signal to noise ratio" increases - making the sound less noisy.
3) Tune the antenna for lowest SWR (standing wave ratio). You'll need an SWR meter to do this. Be sure to get one that will tune HF antennas - or at least one that works in the 27Mhz band. This is another method of improving the S/N ratio mentioned above. An untuned antenna can cause a transmitter to fail - so this is a must for any transmitter's antenna.
4) Obtain the power directly from the battery. Not the accessory terminal or battery terminal under the dash - but to the battery posts themselves. This is the cleanest (power-wise) source in the vehicle.
5) Install filter on the power lines feeding the radio. A rising and falling (with engine RPM) whine sound is usually alternator noise, and a popping sound is ignition noise. The whine sound can be helped by install a capacitor and the ignition noise by using an inductor or coil. So, if you have both noises, you'll need both filters.
6) Install resistor spark plugs and wires. Years ago, we had to get these as an aftermarket item. I don't know if those supplied by auto manufacturers are resistor types or not - so it may be worthwhile to check it out.
Some vehicles benefit greatly from one or more of these solutions, others - not so much. Some vehicles have noisy subsystems unrelated to ignition or alternator. Some tank mounted fuel pumps can be brutally loud and difficult to silence (check with radio on, and turn the key to run - the fuel pump usually runs for a few seconds - listen for static while the pump runs before starting). The vehicles that will probably have good luck are those that you see used as police, taxi and ambulance vehicles due to the radios and electronics in them.
I hope this helps and good luck! Please rate my reply - thank you.
This could be an antenna related problem. Check the PL-259 connector (spin on antenna connection for antenna coax to radio) and make sure it is made up hand tight. Inspect the antenna's base. If mounted to metal, make sure the mechanical connection is tight - and rust free. Rusted parts provide a poor electrical connection. If a mag mount, make sure is is sitting on the flattest part of the surface.
If these suggestions are not providing the expected results, you might need to tune the antenna. If you never tuned the antenna, then you definitely need to tune the antenna. The complete procedure can be found here. The antenna should be checked / tuned after each time it is moved to maintain maximum performance.
Several things are working against you.
1 Antenna location= Needs to be in CENTER of car or truck, and high. no grounded metal can be next to the element (the hot/positve part of the antenna)
2 the only way to really ground the antenna is by having a flat metal ground plane under the antenna. DC grounding does NOT do this, that is a misunderstanding.
3 make sure you use a tunable antenna. I have found the wilson's to be very easy to tune and performe very well, for a base loaded antenna.
4 in short a wilson or k40 magnet mount placed on the very top of the roof in the center will have a perfect ground plane. Then shorten or lengthen the steel whip to ajust your SWR's. You will get the best results this way. This is the ONLY way to achevie good performace.
5 I will say this the absoulte best antenna is the 102"steel whip, if you got the clearnce and dont mind it hitting tree limbs put it on a big magnet mount with a spring at the base and youll have a perfect antenna. But the wilson is shorter and easier to tune.
Truck boxes may be the best looking place to mount a CB antenna but in my experience they are the worst place for performance.
The 'ground' you need is not an electrical ground but an RF ground. The easy answer is that you need to mount the antenna to a mirror or the bumper or even use a magnet mount instead on the roof. The body of the vehicle provides an RF ground that the small truck box cannot. The only way it might work is to use flat, wide ground straps at all four corners of your box to the bed of the truck. You need metal-on-metal contact.
On most mobile communications equipment, it is best that: 1. the power leads are directly wired to the battery terminals; 2. the bracket and radio body are grounded to the chassis of the vehicle; 3. a braided grounding strip be used in addition to the negative power lead; and/or 4. a gutter or trunk lip mounted antenna be used rather than magnetic. Antennas are better made of metal rod (not fiberglass) such as those made by Daiwa, Maldol, Oscar, Hokushin and others. The mount itself should use high quality RG58 coaxial cable such as those by Belden and others.
Hope that this be of some help/idea. Pls post back how things turned out or should you need additional information.