I have a short in the turn signal circuit.

[hmorr8]

I have a short in my 1994 eddie b. version aerostar van. it immediately blows # 5 fuse when it is installed. i suspect something in steering column but i can't find a wiring diagram. has anyone had similar problem? how did you find short? thanks

 

[Alaskanredneck]

I know this sounds strange but before you really start digging in check or replace your marker lights in the front. The filament in the little 194 bulbs can blow and basically weld themselves together thus shorting out your system.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the Aerostar section. Unplug all of the turn signal bulbs (front & back), then with the fuse in, plug in one bulb at a time (assuming that the fuse didn't blow without the bulbs).

 

[hmorr8]

i removed all of the bulbs and the fuse didn't blow. i replaced them one at a time and turned on the emergency flasher and all the bulbs worked but the l. rear bulb. i replaced it and the emergency flasher worked on all four bulbs. i then tried the turn signals and they all worked for about 2 minutes and then the fuse blew again.i removed the l. rear bulb and replaced the fuse. but it blew before i could put it in.it was too dark to continue so i guess i'll try it all again tomorrow. thanks

 

[BrooklynBay]

What amperage was the fuse? It's possible that it's too low. Check the owner's manual or the cover from the fuse panel to see what amperage the correct fuse should be.

 

[hmorr8]

it calls for a fifteen amp, but i replaced it with a 20 amp to see if it would blow, and it did. it has a direct short to ground when it blows. i wish i had a wiring diagram for this model. i need some way to isolate the short. you can measure it with an ohm meter when it shorts but i don't know where the wire goes from the inside fuse box. anyone have a 1994 aerostar turn signal wiring diagram? thanks

 

[BrooklynBay]

Three schematic diagrams of the turn signals, stop lamps, and hazard lamps:

There are two 15 amp fuses (# 1 & # 5). Which one is constantly blowing out?

 

[hmorr8]

after further testing, i discovered that # 5 fuse would blow in normal operation, but with the hazard lights on, all four lights and signal indicators work normally. the turn signals and hazard signal use he same components except for the turn signal switch.therefore, something in the turn signal switch seems to be shorting. if anyone has another idea please let me know as i don't relish the idea of pulling the steering wheel and switch off. for a few minutes the turn signal switch works normally, then something shorts. i have another 94 aerostar and i tried the flasher from it with the seem results.ohm meter tests between the two aerostar van are the same on the flasher connectors.

 

[BrooklynBay]

Sometimes the wires in the steering column get pinched, and cut from the tilt mechanism. Tilt the wheel in a different position, and see if it happens. You could remove the plastic cover from the steering column, and take a look. There aren't too many screws holding it, so it's not that difficult to do.

 

[hmorr8]

I appreciate all of your help , brooklynbay. especially the schematics. I finally found the problem. It was a short behind the fuse panel. after i saw how it was wired from your schematic, i disconnected everything from the low side of fuse 5, and it still blew the fuse. i took one of the blown fuses and soldered an inline fuse on one end and plugged it into the fuse panel.I cut the wire on the flasher and connected it to the other end of the inline fuse. it works like a charm and i now have turn signals and it is still controlled by the ignition.
thanks again. hmorr8

 

[BrooklynBay]

Thanks for the update! The schematic diagrams were a little on the small side, so I wasn't sure if you were able to read them correctly. It's strange that there was a short in the fuse panel.

 

[hmorr8]

actually, when i found that the short was behind the fuse panel i knew i could bypass it. i don't know for sure the short was in the actual fuse panel. i was just very happy it wasn't in the switch. it turned out to be a very easy fix. i'm an electronics technician so i had the tools to find it. that helped too.