T/L CTSY fuse keeps blowing

[RustyPile]

Oh I had no idea you had that tool yeah I bought one,still haven't used it.

[EDIT --- Yes Rick, I know for a fact the "sender" as you call it is a circuit breaker and not a flasher relay. I've had mine apart. I've also made two or three of them using a variety of breaker values. Take yours apart and see for yourself.. On a lesser note... I assume responsibility for you finding the lost MVI, but not your loosing it (;-)]

Come on Rick.. You don't have a reputation of not thoroughly reading these posts. (I' can't find the smiley face) I stated my ownership and use of tool in my post that you quoted.. I've even made mention of the fact over the years I've been here. Suggested others use it also and posted the link numerous times.

I'm not exaggerating the simplicity of its use.. The "secret", if there is one, is how the ammeter works.. It's a zero center meter.. It know which direction the current is flowing. It always points in the direction of the short along the harness.. If, in the process of following the harness and the harness "Ts" off and you continue straight, the needle points the other way, back in the direction of the "T". If WILL NOT lead you down a rabbit hole..

It proved it's worth to me a long time ago when I was still employed.. A friend of mine brought his wife's (cough, cough) Ford Taurus to me.. He had a couple problems he wanted me to look at.. Occasionally, the CHECK ENGINE light would come on briefly and go out.. As you know in those early days of engine management computers, Ford required a breakout box in order to monitor the data stream. There was no ALDL plug and diagnostics were expensive when the breakout box was required. He'd taken to car to a dealership a few times and they couldn't find the cause of the problem.. The second problem was the tail light fuse would blow on occasion.. Again, the dealership couldn't find the problem, and now the fuse would blow as soon as the lights were turned on..

I hooked up my short finder and went to work.. Expecting it to guide me toward the rear of the car, I was surprised when it "led" me through the firewall and forward along the harness branch on the engine cradle going forward toward the radiator. It puzzled me why the taillight harness would take that route but I trusted the tool and continued on..

When I reached one of the engine mounts, I found the harness was tucked up tight against it. The needle stopped right there, indicating the location of the short.. I gave the harness a tug and discovered a small bit of it was pinched between the frame and engine mount.. I unbolted the mount and freed the harness.. Low and behold a wire color coded for tail lights was pinched and shorting to the frame.. I repaired the wire and began to investigate why the CHECK ENGINE light was coming on.. It turned out the computer, for some reason known only to FMC, needs to know when the tail lights are on.. This shorted wire is the wire carrying that signal, and with the wire shorted to ground, the computer never, ever received that signal and I suppose "curiosity" made it set the CHECK ENGINE light..

It took me longer to type this three paragraph narrative than it took to actually locate that short.

 

[Ricko1966]

Come on Rick.. You don't have a reputation of not thoroughly reading these posts. (I' can't find the smiley face) I stated my ownership and use of tool in my post that you quoted.. I've even made mention of the fact over the years I've been here. Suggested others use it also and posted the link numerous times.

I'm not exaggerating the simplicity of its use.. The "secret", if there is one, is how the ammeter works.. It's a zero center meter.. It know which direction the current is flowing. It always points in the direction of the short along the harness.. If, in the process of following the harness and the harness "Ts" off and you continue straight, the needle points the other way, back in the direction of the "T". If WILL NOT lead you down a rabbit hole..

It proved it's worth to me a long time ago when I was still employed.. A friend of mine brought his wife's (cough, cough) Ford Taurus to me.. He had a couple problems he wanted me to look at.. Occasionally, the CHECK ENGINE light would come on briefly and go out.. As you know in those early days of engine management computers, Ford required a breakout box in order to monitor the data stream. There was no ALDL plug and diagnostics were expensive when the breakout box was required. He'd taken to car to a dealership a few times and they couldn't find the cause of the problem.. The second problem was the tail light fuse would blow on occasion.. Again, the dealership couldn't find the problem, and now the fuse would blow as soon as the lights were turned on..

I hooked up my short finder and went to work.. Expecting it to guide me toward the rear of the car, I was surprised when it "led" me through the firewall and forward along the harness branch on the engine cradle going forward toward the radiator. It puzzled me why the taillight harness would take that route but I trusted the tool and continued on..

When I reached one of the engine mounts, I found the harness was tucked up tight against it. The needle stopped right there, indicating the location of the short.. I gave the harness a tug and discovered a small bit of it was pinched between the frame and engine mount.. I unbolted the mount and freed the harness.. Low and behold a wire color coded for tail lights was pinched and shorting to the frame.. I repaired the wire and began to investigate why the CHECK ENGINE light was coming on.. It turned out the computer, for some reason known only to FMC, needs to know when the tail lights are on.. This shorted wire is the wire carrying that signal, and with the wire shorted to ground, the computer never, ever received that signal and I suppose "curiosity" made it set the CHECK ENGINE light..

It took me longer to type this three paragraph narrative than it took to actually locate that short.

Found the gauge but not the sender you think it's a breaker,not a 2 prong flasher. See now I'm going to go nuts until I find the sender or make one. One of those things,I get something in my head and it consumes me. BIAB going to search some more, really. I HATE LOSING THINGS.

 

[RustyPile]

Found the gauge but not the sender you think it's a breaker,not a 2 prong flasher. See now I'm going to go nuts until I find the sender or make one. One of those things,I get something in my head and it consumes me. BIAB going to search some more, really. I HATE LOSING THINGS.

I'm the same way, irritates the h e fence posts out of me... The only thing along those lines that irritates me more is when I come across a tool someone else has left on a car I'm working on.. Unless I know the person, I know that the person who lost it will never find it.

Rick, be sure you go back and read my last post you just quoted.. I edited it and answered your question about what the "sender' consists of.

 

[Ricko1966]

Lol. Look what I found. Look where I was going.

 

[RustyPile]

Lol. Look what I found. Look where I was going.

Looks just like mine.. Those black caps just pull off. Open it up and see what's inside..

 

[idahovette]

Don't do it @Ricko1966 ^^^^^^^^^^^^it's a trap!!!

 

[RustyPile]

Don't do it @Ricko1966 ^^^^^^^^^^^^it's a trap!!!

Everybody in the peanut gallery -- QUITE DOWN!!!!

 

[Ricko1966]

Everybody in the peanut gallery -- QUITE DOWN!!!!

Don't do it @Ricko1966 ^^^^^^^^^^^^it's a trap!!!

Too late,already did it, yep it is a circuit breaker,not a flasher. I'd bet you a circuit breaker and a cheap compass would do the same thing. When I use this thing,I'll try using a compass too see if I can save you all some money.
@RustyPile I swear to God I bought this tool a minnimum of 23 years ago,I know because my son is 23 and I bought it before I moved and he was born. I may have never used it,but mine has lasted a long time,so durable and a good value. Lol

 

[idahovette]

@RustyPile ...no spell check?

 

[RustyPile]

@RustyPile ...no spell check?

Nope, don't use it.. I like to keep my readers and fans on their toes..

Too late,already did it, yep it is a circuit breaker,not a flasher. I'd bet you a circuit breaker and a cheap compass would do the same thing. When I use this thing,I'll try using a compass too see if I can save you all some money.
@RustyPile I swear to God I bought this tool a minnimum of 23 years ago,I know because my son is 23 and I bought it before I moved and he was born. I may have never used it,but mine has lasted a long time,so durable and a good value.

@RustyPile ...no spell check?

 

[RustyPile]

Rick, mine is old enough to have fathered yours.. I bought mine in the late 70s around 1976 when I went to work for an Olds dealer... It's still in excellent condition. I keep the meter in a padded metal box that candy originally came in. My theory is the metal shields the meter from any unwanted magnetic fields. I have made 2 - 3 additional breaker units, using various values on the breakers.. I'd have to look, but I think I have a 10 amp, a 20 amp and for hunting down the cause of blown fusible links, a 40 amp...

I've been in this game a long, long, time.. I started repairing cars for money around 1962 while I was still a teenager...