Forum Discussion

Janss's avatar
Janss
Explorer II
Mar 30, 2022

Electric cord connection to tow car

When I plug in the toad to the motorhome (for lights, etc.), the left rear car light usually does not work. It'll work if I jiggle the plug but only for a second. Don't know if plug is too loose, or perhaps a loose wire, or something else.

I know nothing about electricity. But I do have a small multimeter. Wondering if it is possible to touch the multimeter to each of 6 pins and pinholes on both ends of the plug to find out if each is working good?

Again, barely knowing how a multimeter works, it's just a thought I had. May be way off base.

Any other simple testing ideas? Any simple way to find out which pin controls the left rear car light?
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Mar 30, 2022
    Use a thin bladed screwdriver or pocket knife to spread the male pins slightly for a tighter fit in the female socket.
  • Y-Guy's avatar
    Y-Guy
    Moderator
    Mar 30, 2022
    I'm not sure which connectors you have. On my Motorhome I have a 7-pin connector on my Jeep its a 4-pin connector so my wire has both 7-pin and 4-pin on the other side. If you google "7-pin wiring diagram" or "4-pin round wiring diagram" etc. you should find the schematic you need to test to see if the issue is with the connector or the wiring itself.

    7-Pin RV Diagram

    4-Pin RV Diagram
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Mar 30, 2022
    Y-Guy wrote:
    I'm not sure which connectors you have. On my Motorhome I have a 7-pin connector on my Jeep its a 4-pin connector so my wire has both 7-pin and 4-pin on the other side. If you google "7-pin wiring diagram" or "4-pin round wiring diagram" etc. you should find the schematic you need to test to see if the issue is with the connector or the wiring itself.

    7-Pin RV Diagram

    4-Pin RV Diagram


    I should have been more specific above that I was referring to the common 6-pin round connectors.
  • Janss's avatar
    Janss
    Explorer II
    Mar 31, 2022
    Oh geez! Why didn't I think to google 6-pin wiring diagram! Yes, I have the 6-pin round plug. I see on the diagram which pin is the left turn signal. I'll try your suggestion, Dutch, when I hook up tomorrow.

    I had already tried a couple of contact cleaners without success.

    Thanks all!
  • wildtoad's avatar
    wildtoad
    Explorer II
    Mar 31, 2022
    If the above does not work, might try (if possible) to take the plug apart and check the connections to the pins / sockets.
  • hpdrver's avatar
    hpdrver
    Explorer
    Mar 31, 2022
    If possible, borrow someone else’s power cord and try it. If borrowed cord fixes issue then you know where your problem is.
  • garym114's avatar
    garym114
    Explorer II
    Mar 31, 2022
    After you get the connection problem fixed get a small tube of dielectric grease from an auto parts store and apply to the pins of the connector. This prevents oxidation and corrosion in the connector. Fewer problems with the connection.
  • Skibane's avatar
    Skibane
    Explorer II
    Mar 31, 2022
    ^ Yep - Dielectric grease is good stuff.

    If you put it on clean electrical contacts, it keeps them from being exposed to water - which prevents corrosion on them.

    Putting it on corroded electrical contacts doesn't work nearly as well, since...well, they're already corroded.

    The green Scotch-Brite dish scrubbing pads work great for removing corrosion on contacts. Finish up with concentrated rubbing (isopropyl) alcohol before applying the dielectric grease.
  • Janss's avatar
    Janss
    Explorer II
    Apr 01, 2022
    I'm happy to report that I did as Dutch suggested with a flat screwdriver, specifically with the pin that controls the left light. When I connected the car yesterday, all lights worked! Yay! Of course, I should have checked the lights again before I disconnected the car at home, but forgot to. Who knows what happens on the road with all the bouncing going on.

    The electric contacts, both male and female all look very clean...no corrosion. I had already used Dioxit and Dielectric grease on them awhile ago, with no results.

    Thanks again everyone for all the input!

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