asking the experts - short problem

Mike Stevens

Mike Stevens

PCS Member
Okay, it is my turn to ask the experts. Like Joe Friday used to say, "just the facts".
My coach is a 1961 M-M limo style. It has 87k miles on it. It lives in the barn most of the time. Never sits out unless it is at a meet or show. Everything was working just fine. Never any problems.
While on the way to the barn last week the turn signals went out. So did the brake lights. I found a burnt fuse. This car has the round glass tube Buss fuses. For some reason the 15 amp fuses do not fit into the Cadillac fuse box. Too long. Maybe a few thousanths too long. I got everything working again. I used a 14 amp fuse that was the correct length to fit in the box. All is fine until I set the turn signal lever for a right turn. The flasher (new) will tick once or twice and quit. If the flasher clicks more that once the pattern is very fast. The fuse blows. I have tried other new flashers. What came out was a #552 Sylvania flasher. The old flasher was marked for 4-6 bulbs. There are 6 bulbs in my system. After 3 burned fuses I took all the bulbs out and checked for continuity. All was good. Everything looks clean in the sockets. The bulb bases are clean. Is this an all of a sudden bad ground, a rubbed wire, or a bad contact point in the system? The fuse only burns out when the right side turn signal lights are activated. The turn lever seems to have no difference in feel when you set it for a left or right turn. So experts where do you suggest I look next?
Thank you for your suggestions,
Mike
 
If you have already checked the wiring at the bulb sockets and leading to the sockets, then I would be looking at the directional switch inside of the steering column. Possibly a loose connection or screw.
 
Only comment I have is they make different lengths in numerious amps so you should be able to find correct length 15amp. I probably have one myself as I have quite a collection of those. If you can tell me correct length I will see if I have one and if you are in Nashville this weekend I bring it with me.
 
from your description it would be in the right turn signal circuit. I'm guessing the brake light doesn't blow the fuse. if it does to look in the rear first. try cranking the wheel all the way to lock and see if it still blows the fuse.
if not, look in to the turn signal cam for a rub. start there and trace it out. it's a pain to find one small spot but the only way I know how is to start at one end and work to the other. the other way is to start at one light take it apart pull the wires out into the air, test. then go to the othere do the same. you get one apart and the fuse doesn't blow run that set of wires back till you find were it was grounding out. normally it's at a point were it goes into something.
one place on the out side that things happen the most is the rear. lot of clips holding the wires to the frame and long runs dangling. but re reading your statement I would guess it's under the steering wheel all one can say is good luck
 
Paul and Ed are spot on. If applying the brakes doesn't blow the fuse, the issue is in the turn signal switch. It could be something as simple as a piece of metallic debris shorting the breaker plate in the switch.
 
M-M turn signal

The left turn signal works fine. The brake lights do not blow the fuse. Only when I turn on the right turn signal does the fuse burn out. That is also the only time the flasher cycles very fast. I will be using all your tips and opinions soon to check it out. Not before the Volunteer meet in Nashville this weekend.
I will post what I find when it happens.
Thank you one and all,
Mike
 
if the flasher cycles rapidly, then that might indicate a short circuit in the bulb itself. I would replace all the bulbs that function as directional bulbs, and closely examine them for visual defects. Won't be the first time that a bulb shorted out internally..
 
Sorry Mike, gotta do it........why not only make left turns??? It can be done, just takes a little planning.

BTW, that's the voice of experience right there!!
 
left turn circuit is independent from the right. the only place they come together is at the stop light switch. so if stepping on the brake doesn't blow the fuse the circuit going to the rear is OK. as the turn and brake used the same wire going back. the only thing left is the right front and the cam under the wheel. take the right front light apart and check all that wiring around that is exposed. the park will be the brown one the turn is yellow or green I can never remember which is left or right. the reason the flashers starts slow and goes fast is because it works by heating up a bi metal spring wire. gets hot opens, cools off closes. the short is over heating it so it doesn't get the chance to cool. kind of like your hart when the bikinis go by. one quick check just in case would be to clamp the battery cable on the light housing touching the socket and then to the frame. a poor ground with a weak flasher can cause the same problem but that normaly does not blow the fuse.
then again with wiring and old cars there is no normal.
 
left turns only

Russ,
It is my understanding that UPS now has a practice that they only make right turns when possible to do a route. Supposedly saves time.
Your input is appreciated.
Mike
 
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