On my 86 Toyota truck the cigarette lighter only works now and then.Don't care about the lighter,but I use that port for my GPS speedometer.What's the problem and solution...thanks.

 

poor contacts on the inside i would think. you can buy an aftermarket replacement for less than $10.

 

Done any recent dash work?
Make sure the connection on the back is still fully engaged.
30 year old truck connections as mentioned by oldblue need replacement

 

The fellow at O'Reilly auto parts changed the whole unit,still doesn't work and now my radio and clock are also non-op.A 15 amp fuse was blown,changed that and those three above mentioned still don't work.

 

The clock and Cigarette Light ("Supplemental Power Port") both run off the 15A cig fuse, but the radio is on a 7.5A fuse. http://personal.utulsa.edu/~nathan-b.../2powersou.pdf

I assume you rechecked the cig fuse (if not, LOOK at it, don't replace it just on the hope the short went away). But check the radio fuse too. It's next to the cig fuse, so if you're clumsy you might have wiggled it out.

Most likely, you've got a wiring problem right behind the cig lighter, and your friend at O'Reilly, despite his efforts, made it worse. So you're going to need to look at the wiring and find the opens and the shorts. What do they look like? I have no idea -- I need a multimeter to trace it out. You do too. Start by pulling the cig fuse, find which side has voltage, then turn off the key and measure resistance to ground on the OTHER side. You should be just measuring the resistance of the clock, which should be 100s of ohms. If you've got less than 10 ohms, you've got a short on the circuit. Go find it!

 

+1 for all of the above. Inspecting and/or cleaning connections (not replacing things) should be the first thing you do when you do not get electrical power somewhere.

One you've done inspection, look at schematic and take measurements. You should have multi-meter. Next to our senses, it is the most important electrical diagnostic tool.

 

Thanks for the replies.Have the thin radio housing loose.Haven't checked any wires yet as my hands are half shot from pinched elbow nerves and the brain is fading out on this old timer.Just have a probe light tester with a alligator clip.The radio and clock worked this morning before I pulled the front of the radio housing off.Might have to wait till I can find someone with a multi tester and knows how to use one,I don't know a thing about them.I see that the two wires going to the back of the cig lighter have been fooled with before.Don't know why that fuse blew though?...again thanks for the replies.

 

Hi MLDave, here's schematic...

 

The fuse that was replaced yesterday was blown again this morning when I checked it.I put another one in to see if the radio,cig lighter or clock would work..no go.Didn't check again to see if it to was blown.Likely will wait to find someone with good working hands to check the wires for me.

 

A friend came by as I was looking at the wires behind the cig lighter and tested everything with his multi meter.There was a dead short in the new cig lighter kit.He took it all apart and a washer was touching the inner copper sleeve....thanks for the replies.

 

Good to know you found the problem, Dave.
Now we see how replacement parts are not always the solution to many problems.