1999 Mercury Villager Estate. The brake lights fuse keeps blowing immediately when inserted

On the audibles from the adjacent fuse holders, it sounds like all you’re doing is grounding the voltage from the brake light fuse. That’s normal.

I’ve gotten spoiled by having the factory wiring diagrams for all my fords, if I had a Villager I could tell you exactly how this is wired.

I did find an online diagram that shows splice 239 feeds the fuse, brake light switch, and trailer tow control unit. These wires are red/white stripe

Since these are not factory diagrams I can only guess that the trailer control unit is somewhere at the rear of the van & is probably a box of relays. Does your owners manual have anything on these?

helminc.com will have the factory wiring diagrams which are worth their weight in gold.

rfranks78, you are not getting what I am trying to tell you. The problem is not associated with any other fuse. Pretend this is all caps Look for something else that is not working. This is where your problem lies, unless it is just behind the fuse panel.

When this fuse is blown, whatever is attached to S239 is also not working. That could be a dashboard light, 4 way flashers etc. Test all your systems and see what is NOT working besides the brake lights.

Oh, gotcha Keith.

Here’s what I’m seeing from my new alldatadiy.com subscription. Really having a hard time finding what circuit S239 is though.

There should be a page that lists the circuits in alpha/numeric order. That will help you identify the circuit.

S239 connects brake light fuse, brake light switch and “trailer tow control unit” together. See my previous post.

I’m not a huge fan of ALLDATA schematics because I have found that sometimes they appear to be scans from Haynes or whatever else is out there and may or may not be correct or complete.

This is why Helms is equivalent to a lifeboat when you’re on the Titanic. They’re clear enough that many problems can be resolved perusing the manual while sitting in an easy chair with a cold one… :slight_smile:

Ah. Thanks! I’ve already tracked the tow light connection back about mid-body and have disconnected the connector that is located there. Still have a short though. Maybe that wire is shorted farther up towards the fuse box somewhere.

I’ve purchased a month of Online Service Information for this vehicle on Helminc.com also, but the link they sent me to the actual manual doesn’t work. Grrr.

Contact them; they will sort it out.

There’s an old mechanic’s trick but I hate to recommend it due to the obvious pitfalls. A heavy jumper wire is made with a male spade connector on each end. Preferably with an assistant watching closely, the jumper is inserted into the fuse slot.

At that point one watches closely for the location of a pop, puff of smoke, and/or the sound of frying bacon followed by ripping the jumper out That will be the short… :slight_smile:

Repairs are made as necessary to the hot spot. I am NOT advising that you do this; just saying that it has been known to happen and is a last ditch, no light at the end of the tunnel, when all else fails option.

Like ok4450 mentioned sometimes simply looking at a good set of diagrams is all it takes to figure out an electrical problem.

Strange that we cant quote folks in our replys.

To rfranks78 I wouldn’t be a bit surprised if the problem is in the tow light circuit.

I FINALLY FIXED IT!!!
Well, I use the word “fixed” loosly, but whatever. The fuse no longer blows now and the brake lights work again! At least the driver side brake lights do…

I ended up cutting the hot wire going into the black towing light junction looking thing stuck in the sidewall on the back drivers side just behind where the drivers side tail light assembly is. The real short must be beyond that, but I’m not worried about having the towing lights working anyway. It’s a minivan. If I need to tow something, I have a 5.9L Ram pickup for that.

Thanks to all for the help! This site is outstanding! I posted this on a couple of other sites and haven’t gotten a single reply still. I’m coming here from now on!

Nice job & congrats on the fix. I’d bet you are as happy as a whale in the sea of Cortez.

Do a google search on “whale, sea of cortez, fishing net”. Watch the 8 minute video. Amazing

Haha! Pretty much!