245 Automobile Adapter

[bwhite]

Bought my 245 many years back when they were new, bought the 12v auto cord at the same time to recharge and run while driving. I should have paid more attention early on and seen the problem but oh-well. Anyway, seems that the scanner never powers when plugged into any vehicle I use it on.
The scanner charges fine off the wall-wart, the voltage off the auto charger and wall-wart are similar. Polarity is the same.
Any thoughts? My only supposition is that the voltage out of the car is just a tad too high for the internals of the radio and thus it won't allow it through, I guess I can prove this out by trying with the engine is off next time I have dead batteries.
Thanx for any insights.

 

[Al42]

It could be that the center pin of the plug is smaller than the center hole of your cord. Or it could be that, under load, the voltage coming out of the cord is too low.

the voltage off the auto charger and wall-wart are similar

Similar within 0.1 or 0.2 volts? Under load?

 

[bwhite]

Pin feel snug, I do notice that the plug (like their darn battery packs) seems to be custom.
Don't have the equipment to test under load, doesn't look like any voltage conversion occurs and other fairly high power devices work off the lighter.
Soon as the radio runs out of batteries again I'm going to see if it will power with the engine off which would be more like 12v instead of 14-ish. I'm starting to talk myself in to the radio cutting off too high of a voltage. Might take a few days for this update.

 

[Dubbin]

You either have the wrong plug or the fuse in the adapter is blown. 14v is not going to keep the radio from working.

 

[Al42]

I'm starting to talk myself in to the radio cutting off too high of a voltage.

There's nothing in the radio to do that.

 

[bwhite]

No fuse in the cable.

 

[Dubbin]

Is this a cord that you plug into the cigarette lighter? If so then it probably does have a fuse in the end of it (most do). Have you even checked to see if you are getting power coming out of it?

 

[bwhite]

Yeah, contunity thru both the + and - from end-to-end.
Seems like such a simple thing....

 

[Dubbin]

What kind of voltage are you getting?

 

[bwhite]

Well, tried again, same symptoms where 245 would run ever so briefly then die.
Had my volt/ohm meter in the car, traffic was a parking lot so I kept fooling around
looks like the ground side of the circuit was open about 50% of the time, if I remember
correctly, the 245 (with the volum switch in an on position) doesn't like to start on
its own when power is applied. Gonna see if I can get a new power plug (the part that goes
in the radio; I'm pretty sure it came up as a proprietary size last time I stopped at Radio Shack.
Time to try again.
Thanx all.

 

[Al42]

Gonna see if I can get a new power plug (the part that goes
in the radio; I'm pretty sure it came up as a proprietary size last time I stopped at Radio Shack.

It's either a B or a C - there are a few threads about it, but I can't remember which one it is. (The center pin diameter is different - it fits on the right one but is loose on the wrong one, so you can't find out by trying it out. Both plugs are the same OD, so they're both snug.)

 

[bwhite]

Resolved.
The ground side looks like it was indeed intermittently open.
Apparently in the past it was usually behaving when I tested it but not now.
Bought an "H" plug from RS (to go into the radio), used some spare wire and resoldered off of the original cig lighter. RS wanted to sell the whole rig for about $20....made of mix/match snap together components, more than the custom one sold originally.