our tow truck has a problem, insight anyone

[azlee56]

We get home last night and our neighbor comes running (yes she really ran to us) and said your truck has been doing something strange. Off and on the tail lights/brake light (don't know which one really) would start blinking. She said she kept watching then it wouldn't do it any more, and sure enough the batteries were dead. The truck was off, has been off for 2 weeks. What in the world would do this? The batteries were probably weak to begin with. Ford 250 7.3 2000.

Any ideas?

[rnkburg]

Sometimes the brake controller will control the brake lights may be sticking on, or the brake pedal switch which some vehicles have is sticking on and off. Other than that security system maybe flashing lights or bad light switch on dash

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[azlee56]

I'll have him check the brake controller. I am surprised it happens when the truck is off!

[crash]

Maybe security system shorting out.

[SAABDOCTOR]

AZLEE the brake light circut has power all the time. Even with the key off the brake lights will work and so will the security. but if the security were the issue the front parking lights would flash also. I am not a ford mechanic. but on some cars when the battery gets weak the control module do some crazy stuff so it just maybe a bad battery.You should see what Saabs do when the battery starts to get weak good luck hope it is simple!!!

[DJ85]

Fords are know to start doing strange stuff when the batterys are at low voltage. I agree with starting to just make sure the battery are good condition first is the best place to start. Sounds to me like a relay may have stuck and started tripping in and out with the voltage dropping. Good luck!!!!

[JRTJH]

I agree with the battery causing a problem. Additionally, Ford uses a pressure switch on the top of the brake pedal to activate the brake lights. Usually when that switch fails, the brake lights will not come on, but occasionally it will fail causing the live contact in the switch to vibrate against the housing making the brake lights "blink."

If it's not the battery or the brake switch, I remember you were having problems with your trailer brakes a couple of months ago. So, looking at past issues, I'd think there could be a problem with the ground on the trailer brakes or the breakaway switch.

My best guess though would be the battery, the brake switch and then the trailer..... Good Luck !!!!!

[SAABDOCTOR]

by the other replies it looks like the Ford enginers were playing with trolls

[JRTJH]

Originally Posted by SAABDOCTOR

by the other replies it looks like the Ford enginers were playing with trolls

Barney,

Ford engineers are trolls..... Remember, anyone who lives "under the Mackinaw Bridge is considered a "Troll" by people in the UP. Detroit is "WAY DOWN UNDER" LOL

[azlee56]

well the man charged up the battery and nothing blinked.....yet. The trailer breaks we got fixed, it was the ground wire had got split and broke. We do need new brake pads or whatever they use now.

spoken like a true mechanic huh?

Ok guess we better spring for batteries, we need them any way.

[DJ85]

Well look at it this way maybe it was doing it's best to tell you fix me fix me.

[azlee56]

LOL, at least it doesn't honk on its own to tell me.

[DJ85]

Not yet anyway!!!!!!

[JRTJH]

Originally Posted by azlee56

LOL, at least it doesn't honk on its own to tell me.

Fords do "honk" to tell you..... When you use the key fob to lock the truck, one honk means "locked and good" two honks means "It didn't work, dummy"

[Brantlaker]

Ford Recalled a lot of E-break switchers because of shorting out causing fires under the hood. Also in my experience (35 Years working in Ford service depts) It is probably a weak battery.

[SAABDOCTOR]

Glad it was that easy! As for the trolls... Well Saabs were made in Trollhatten so Saabs were made by Trolls! My 1978 Saab has the that sticker on the back window with the troll doll. and yes azlee they use brake pads now!! Have a great day