eletrical theory question

[surpip]

so on the mini, (crappy lucas wiring) in the mornings, the radio cuts in and out , this only happens in the morning, but to me, the car beeing cold should have nothing to do with how well the ele. system works right?
only thing i can think of is that the batt. is charged by the ride home in the afternoon, and in the morning with the lights on and the heater fan on , the alt. cant keep up, and in the second half of the drive, the ele. system is tapped and cannot keep up with everything running.


any thoughts?


i know i need to just replace the wiring.

 

[HarryH3]

Lucas - The prince of darkenss! Lucas refigerators are why the British drink their beer warm.

Could be that your radio itself has a problem. Electronic parts often fail only at certain temperatures. When the temp changes, expansion or contraction will make the circuit connect again.

 

[surpip]

ya im pretty shure that isent it, because it has happen with pretty much all the radios i have put in it, and all the combinations of 12v+ wires i have hooked them too

 

[Blue85]

It is POSSIBLE that a low voltage condition makes your radio cut out. You can test this by turning all the other stuff off for a while and see if it still has this problem.

I think it's more likely that you have an intermittent connection somewhere.

 

[surpip]

ya when i turn off the headlights the radio seems to work better, but i can do that at night
im pretty shure i just need to re wire the whole thing

 

[anjieandjohn]

Sounds like a loose connection somewhere...I have seen this type of problem many times on the differeint Navy electronics I have worked on. Maybe some type of corrosion near the alt or a broken wire that is hanging on by a hair. I saw problems like this mainly in the high voltage area of my equipment and it also sometimes turned out to be a wire shorting through the insulation. Good luck.

 

[surpip]

ya i'm a AT in the navy so i pretty much know my S#$t when it comes to that, i am almost positive it isent a loose connection
could be wrong wont be the first or the last time

 

[1989blazer]

IN my EE clases, I was taught that many electrical failures are mechanical, meaning that connector failure is a leading problem. Corrosion between dissimilar connector metals along with fatigue due to vibration can be leading causes of connector failure. Get a bit of wire and connect your radio directly to the battery. Then see if it cuts out. If so, then perhaps the failure is inside the radio. I've seen cold solder joints fail over time as well, or even traces on circuit boards. Hope this helps.

 

[Greg72]

Is the Lucas stuff some sort of bizarro "floating ground" system or non-standard grounding layout? All I know about Lucas electrics are the jokes that have already been told...


Most of us are familiar with 12V negative ground wiring, but not all vehicles use that system. Is the radio a "factory" unit, or a more modern aftermarket one...???

 

[surpip]

no it is a regular 12v+ -ground system
radio is a cheap arse cd player, but same symptoms with a kenwood deck(wich left the car a 70MPH on the freeway because of this problem) and a sony unit that was stolen.

 

[Greg72]

no it is a regular 12v+ -ground system
radio is a cheap arse cd player, but same symptoms with a kenwood deck(wich left the car a 70MPH on the freeway because of this problem) and a sony unit that was stolen.

When you say "radio cuts out" do you truly mean radio, or would this happen if you were playing a CD too??

If the sound only cuts out when the radio is on, I'd immediately be looking at an antenna issue....intermittent ground probably. If the antenna wasn't reliably grounded, the tuner could "lose" it's lock on the station and might mute the output as opposed to blasting "static" out the speakers....

I think the antenna derives a ground from where it's base attaches to the fender, and also from the socket where it connects to the deck itself.



More ideas.

 

[Leper]

Where does the radio get its power? Is it in the fuse block, or tied to another wire, or from the batery? You could try running it straight to the batt to eliminate the connection problem. The cooler temps and higher humidity may make a good connection weak or loose.
Like the last post said, define "cuts out"

 

[surpip]

cutts out= stopps working and lights go out

 

[Leper]

Loose ground on radio. Where ever it is grounded, run a wire from that point to another point on the body, mabey firewall, or if grounded to firewall run a wire from that point to the battery ground. Hell run em all to the battery, just remember to turn the radio off.

 

[BobK]

How about condensation?
Only happens in the morning right?
Maybe a little condensation is shorting things out.

 

[surpip]

not a loose ground
ground checks 1.2 ohms and stays there with all the jiggling i can do to it
i dont want to just rrun a wire to the batt. kind not really fixing the problem to me

 

[wildbilzrydn]

Running a wire to the battery would be the first step in your trouble shoot, you could run it outside the car for example. If the radio works good then, then its in the car wiring. If the radio works bad, then its the radio....

 

[Greg72]

not a loose ground
ground checks 1.2 ohms and stays there with all the jiggling i can do to it
i dont want to just rrun a wire to the batt. kind not really fixing the problem to me

If all the power to the deck is going out, you KNOW it's a break in the feed/ground to the deck. If you're convinced that the ground is good then it HAS to be on the supply side.

You may not like the idea of running a direct wire +12V from battery to deck, but that will confirm that you've got intermittent power in that circuit.