I replaced my radio today and after reassembling everything, the cigarette lighter is no longer working. I tried putting back the stock radio but the problem persists.

I checked the fuse and it was good, however there is no voltage at the fuse. If I jump the radio fuse to the cigarette lighter fuse, it works. Obviously, this is not an ideal solution.

I found a thread here that indicates that there is a second fuse under the hood, however, the diagram posted refers to fuse 5 under the hood but I don't have a fuse 5.

(I tried to post a picture here but my post count is too low, unfortunately)

Curiously, my indicator light for 4WD (PART TIME) stopped working at the same time. Whether or not it's related, I'm not sure.

I'm now at a loss. Any suggestions or words of wisdom?

Edit: Looks like the info below was referenced from the incorrect year FSM, so is to be corrected.


Cigar lighter gets ignition switched power from fuse 18 (20A) behind the glove box. That fuse is supplied on the same circuit as fuse 17 (25A) which powers the front wipers. If the front wipers work with the ignition on, the ignition switch is OK and the fault is at fuse 18 or the wiring to the cig lighter. That ignition circuit is supplied from fuse 13 (40A) in the under hood PDC. Check that fuse if the wipers are also dead. If that fuse is good, check for power at the red 12 gauge wire going to pin 4 of the ignition switch.

The radio is on an unrelated circuit supplied by a different PDC fuse and wiring, and uses a different set of contacts in the ignition switch.

You should also have a permanently powered accessory socket according to the FSM. that gets power direct from PDC fuse 17 (20A).


The 4WD lamp could be a lamp or switch failure and just coincidental.

So, update on this. It did turn out to be Fuse 15 "Accessory" under the hood. It was blown. however, I've replaced it and there is now voltage to the fuse behind the glove box.. but when I have something plugged into the cigarette lighter, it rapidly connects and disconnects and there is a clicking/buzzing sound coming from the dashboard area.

Not sure which year FSM I was looking at earlier but it looks like it was the wrong one. I'll have to correct what I posted for others that may find the correct info useful.


The clicking/buzzing sound would be the accessory relay under the dash. It should be behind the drivers knee panel, at the side of a bank of coloured connectors behind the driver side speaker. It seems like it may be bad, not getting sufficient voltage or has a bad ground. I'd try swapping it first to see if that fixes it. The opening and closing of the relay when the circuit was loaded may have spiked the fuse causing it to blow.

(Jonny beat me to it but for a bit more info I will post this as written.)

The buzzing sound is likely from the lighter/accessory relay. It is under the dash near the steering column. That indicates low voltage to the relay coil & can cause the relay to open & close repeatedly which would affect the lighter socket & cause it to act as you describe.

If you are in fact losing power to the relay coil that power comes from the ignition switch which also powers fuses 13,14 & 15 in the fuse block behind the glove box. So see if you are losing power to those 3 fuses which are for your wipers, turn signals & radio.

Since you say you have jumped the radio fuse to power the lighter socket I would start there.

I don't presently have that jumped, I just did it as a test to make sure the wiring from the fuse itself to the outlet was good.
The wipers, turn signals, and radio all seem to be working fine, even with the 40A fuse removed from under the hood. The only thing that seems to be affected by that 40A is the lighter.

I'll check out the relay and confirm.

Thank you!

EDIT: I believe I found the relay. It must have been replaced before because it was hanging down and had a NAPA branded relay
EDIT 2: I'm a little confused. The relay that was in there is an EP27, which indicates that it's for the signal flasher, however, with it removed, the signal flashers are still working. Is it possible that it was previously replaced with the wrong relay? If so, what is the correct relay?
EDIT 3: I found a relay diagram and it seems to indicate that when it's powered on, the top and bottom pins should have continuity and when it's off, the bottom and middle should have continuity, however, when there's no power, there's no continuity on any pins and when there is, the top and middle have continuity. I could be reading it wrong but that seems interesting.

That’s true but the relay trigger (coil) gets 12v power from the same power supply as the 3 fuses mentioned which is from the ignition switch. If the relay is buzzing & cutting in & out you should check both the 12v & ground.

Possible wrong relay. You need a standard automotive relay. It should have 5 terminals. The 2 with the smaller gauge wires will have resistance between them since it is a magnetic coil. Of the other 3, 2 should have continuity when not energized & the 2 that are shown in the diagram should have continuity when energized which is when the key is on. That is how the relay powers fuse 19. Any relay in the PDC that fits (same size) can be used for testing purposes.


Here is the page from the FSM showing that circuit for 2000. You can check the wire colors to the relay.

Attached Images

A little off topic, and just curious, Strra, how long have you owned this Jeep ?

This relay isn't reacting like that whatsoever. I give 12v to the outer two pins and the top two (horizontal) pins have continuity. When no power is applied, there is no continuity between any of the pins. When it stops raining, I'll try to harvest a relay out of the Patriot and see if it works.


Two days. I just registered it Tuesday. My grandmother bought it 11 years ago when my grandpa died so she could use it to plow the driveway and it ended up just sitting in the barn for 10 years until I offered to take it off her hands.

OK, is it possible that some of these issues, were pre-existing, and unrelated to your radio swap?

It's possible but I'm like 80% sure that my wife used the cigarette lighter port to charge her phone the day prior.. but then again, maybe it was plugged in and she didn't notice it wasn't charging!

The 4WD indicator was working for sure before because it was in 4WD when I turned it on the first time and the indicator was on.

UPDATE:

I thought I posted this follow-up but maybe I didn't submit it.
Replacing the relay fixed the issue. I got an RL45 from AutoZone. In the end, it turned out to be both the relay and the fuse. Perhaps the relay was bad or just the wrong one and blew the fuse.
Thank you to everyone that helped me track this down!