help please - lost power to cigar lighter , dome light , map light and more 1972 dart

-

moparjon

Well-Known Member
Joined
Feb 9, 2009
Messages
130
Reaction score
19
1972 dart 318 daily driver

i was using a small air pump to fill a tire with air ( not the best idea i know , but have been using it a lot lately , no problems before ) plugged into the cigar lighter outlet . anyway it was going along fine for a few minutes when it suddenly stopped . i put the lighter itself back in , it did not heat up . i checked power to the wire attached to back of lighter receptacle and it did not have any . checked all fuses with test light , they all lit up ok . the instr. lps , only with the headlights on . also changed that fuse , same result . map light , dome light , glove box light all are not coming on . hazard flashers also not working . can it be the relay delay ? would that cause all the other stuff to crap out ? looking around nothing appeared melted or any burning smell . lights work with headlight switch , turn signals work . instrument cluster lights appear to be working . dome light does not , even with headlight switch wheel turned all the way left . not sure what to try or check next . any ideas ? thanks
 
Last edited:
download the wiring diagram for your car (mymopar.com) and trace out where the power to those devices comes from.
 
download the wiring diagram for your car (mymopar.com) and trace out where the power to those devices comes from.

i have the factory service manual with wiring diagrams , i will check those thanks
 
remote possibility... (I don't recall what gets power through the fusible link) but a fusible link will fry without leaving any external signs.
 
oh crap , silly me . i must just be remedial today . i just noticed there is a dedicated fuse for the cigar light and dome light lamps , i only checked one side , which was getting power . i did not check the other side because of the aftermarket radios clock wire was in the way . fuse was burned . getting power to both dome and cig. lighter now , will check the rest . thanks everybody . question now is , should i keep pumping up the tire this way ? will it hurt anything ? or just keep blowing fuses ? it just need to get another week or two before i can by tires .
 
The fusible link protects everything from a battery short.
If there is voltage at the fuse box, then the fusible link is intact.
- That said, if there is just one strand remaining, it will still show battery voltage when everything is off.
Same with a poor connection anywhere. The connection only reveals itself to have high resistance when current is trying to flow through it.

Operationally the wiring on your '72 will look something like this.
The shop manual diagram will have the details of the layout, colors, connectors, etc. Look to see what the cigar lighter and dome light share on the fuse panel.
They probably use the same feed wire from the main junction.

Main_charging_wires_pluss.png
 
oh crap , silly me . i must just be remedial today . i just noticed there is a dedicated fuse for the cigar light and dome light lamps , i only checked one side , which was getting power . i did not check the other side because of the aftermarket radios clock wire was in the way . fuse was burned . getting power to both dome and cig. lighter now , will check the rest . thanks everybody . question now is , should i keep pumping up the tire this way ? will it hurt anything ? or just keep blowing fuses ? it just need to get another week or two before i can by tires .
The question is why is it blowing fuses?
Its a 20 amp fuse?
 
i think because i been running this air pump about twice a day for the last few weeks . at at least ten minutes to 15 at a time . fast leak that cant be repaired . i am getting new tires soon . it only blew once , so far . we'll see how it goes ,

i think its time for a new glove box though


HPIM8167.JPG
 
interesting photo! the Classic Ind replacements are pretty good, and they can go in without bending if you take the door hinges off
 
yes 20 amp fuse , also at least 17 years old . i have not replaced that one as long as owning car .
 
yes 20 amp fuse , also at least 17 years old . i have not replaced that one as long as owning car .
The pump should have a label with the max amps it should draw, and the voltage that current was measured at.

If its drawing more current than listed, it could be the motor is failing internally.
The hotter the internal wiring gets, the more current it will need.
The more load put on it, the more current it will need.
The longer it runs continuously, the warmer it will get.
Heat will speed its demise as insulation and connections start to fail.

Someone who knows more about little DC motors to correct or add to this.
I beleive that unlike a light bulb, running a motor at higher voltage may reduce the current needed for a given load.
If so, it may be better to run the pump with the engine running so its at roughly 14 volts, rather than on battery at 12.5 ish Volts.
Hopefully someone can chime in who knows if this makes sense or not.
I know its true if an AC motor is rewired for 220 from 110/115 but that's not the same as this situation.
 
Bypass the ammeter at the firewall And run the charging wire from your your alternator through a fusible link straight to your battery, while you're at it.

The fresh, clean, not-on-fire interior of your car will be worth it.
 
PS. Age on a fuse shouldn't matter.
PSS. If you are running the pump on battery (engine off), the ammeter will show the current draw. I actually think its better to have the engine running but in that case the ammeter won't show how much current is being drawn by the pump.
 
Last edited:
interesting photo! the Classic Ind replacements are pretty good, and they can go in without bending if you take the door hinges off

Got one through them for the Wife's Dart and it was really nice quality.
 
ok , here's what happened so far . everything was back to working fine in the Dart . then i again tried the air pump . lights out in seconds , after putting the last 20amp fuse in . then i took the Valiant to get more fuses . thinking along the way , ..... maybe that drivers side door jamb switch that has been acting up could be the problem . so , when i got back , put a new 20 amp fuse in with both doors closed . plugged the air pump but did not turn it on . opened the passengers side door , no dome light . wiggled that sides door jamb switch , dome light came on , then went out and burned out fuse in seconds . so then took the pump plugged it into the Valiants cigar lighter and buzzt' , burned up the fuse/lights out . so , i am 92 percent sure its just the air pump shorting out . since both of these cars were fine for years . i will update if this is not the case . thanks to everyone .
 
Why not put battery clips on the pump and go right to the battery, eliminating all the fuse problems in the car. You could always put a fuse in the pump wiring that is hooked up to battery.
 
Why not put battery clips on the pump and go right to the battery, eliminating all the fuse problems in the car. You could always put a fuse in the pump wiring that is hooked up to battery.
Its not a fuse problem. Fuses are working fine. When a pump that should at most pull something like 8 amps is blowing 20 amp fuses, the problem is the pump.
 
Time to buy a big boy compressor and/or an air bubble. Craigslist is full of them.
 
-
Back
Top