Never used a forum before. Just purchased this truck. I really like it. 300K and it purrs like a kitten. Should my dome light come on when i open my door? Can't find a fix from the downloaded manual.

 

There should be multiple ways to turn on/off the dome light. I don't have diagrams for your truck, so for example:

1) ajar switch - on only
2) RKE (remote) - on only
3) light switch or dimmer switch - on/off
4) dome light button - on/off

If it's set too off by accident, ajar switch doesn't have the ability to turn it back on if it's turned off globally by other device.
If you think there's a problem with your driver front ajar switch, try other 3 doors. You can also remove the switch and do a bench test but I highly doubt all 4 ajar switches are bad unless there is a break at the splice along the circuit.
1) To do the bench test is simple, remove it, the switch should have only 2 terminals and it's a normally-closed type, use multimeter and check on continuity on both terminals at rest, it should beep, press the button firmly by hand, no continuity no beep, then the ajar switch is good.
2) While the ajar switch is removed, check on the harness side of the ajar switch connector, locate one of the two terminals with BK/VT (black/violet), that terminal should have ground signal at all time, you can use your multimeter and do a quick continuity test, red to BK/VT, black to chassis ground, if you can't find any, run a long jumper wire to your engine block or even your battery negative terminal, it should beep.

Also check your instrument cluster, there should be ajar lamp telling you which exact door is not closed firmly. If you can see that that also tells you your ajar switches are working fine.

 

I am going to enjoy being part of a community.Thank you for the quick response, letting me know that my efforts to join worked.I will start looking into the processes you have suggested.. Thanks again and I'll post results.

 

A lot of folks don't have a multimeter and less know how to utilize one.

If you don't have one , there is a very simple tool to help determine if your circuit has power or ground. It is called a test light.
You don't have to poke around with a meter probe then take your eyes off to go look at the meter.You have the test light in sight at all times to obtain an instant answer.
You do not use the test light to check any computer circuits.
Excellent choice for checking power and ground and cost much less than a multimeter.
You can connect the test light clip to a good ground and when the pointed tip of the light contacts any source of power the light will illuminate, it is that easy.
If you connect the clip to a source of power and touch a good ground , the light will also illuminate to tell you what you have.
You ALWAYS check if the connection for the test light is good by checking if it works as connected first and if OK, continue to test.

 

But since early 2000 all the ford E and F series begun using negative trigger at the door ajar switch, entire circuit from the switch up to, say SJB, has no 12v, so test light, measuring voltage is not going to work in his case. I mentioned continuity check, I didn't mention resistance check with ohmmeter, and continuity is the most basic check, on chapter one, on how to use a multimeter.

 

Would anyone know if 2012 super duty short bed has the PUCK system for a 5th wheel.

 

Referring to the earlier post using the test light. If the circuit is looking for a ground, which it is in this case, until that wire finds a ground , IT WILL lite the test light.

If it was connected to a good ground , the light in the vehicle would work.

 

New subject...With my newly purchased truck. The horn only works sometimes. When it does I seem to be pressing a different area.??????????????????

 

Try to remove it and lubricate it with synthetic grease.