Speedometer not working and blinker fuse blowing

[dawgsfan08]

89 f350 7.3 5spd. Speedometer is not working. How does my speed-o actually work anyways? Also, Windows don't work, and blinker fuse keeps blowing.

 

[crash-harris]

Speedo is cable driven.

Windows - do the motors make noise when you hit the switch?

Blinker fuse - you have a short in one of the wires. Usually happens in the taillight wiring right under the back of the bed or behind the light housings.

 

[madpogue]

Does the turn signal fuse blow right away, when you turn the key on, or when you attempt to use one of the turn signals?

 

[dawgsfan08]

Blows when using right turn signal. Motor doesn't make any sounds. Just quit all together. Also brake pedal travels a lil ways before light comes on. I caint find where to adjust brake switch

 

[madpogue]

Start by removing both turn bulbs on right side (RF & RR). If it still blows, check wiring as mentioned above. Turn signal switch on the column is another possiblility.

Does the hazard fuse blow when you use the hazards?

 

[DaveBen]

Start by removing both turn bulbs on right side (RF & RR). If it still blows, check wiring as mentioned above. Turn signal switch on the column is another possiblility.

Does the hazard fuse blow when you use the hazards?

I had a similar thing happen to my clearance lights. It took me weeks to find. I started looking at the front bumper and worked my way to the back and then up. My taillights would cause a fuse to blow every time I turned them on. I finally got to the clearance lights and I found the right side first light was bad. It had failed to a SHORT circuit, causing the fuse to blow. I replaced it and was GTG. This was the first light that had failed to a short that I had ever seen. All of the rest failed to an open and would just not work, but did not cause a short that blew fuses. I started by looking at the wiring first, thinking the squirrels had feasted on the wires. After a day of crawling under the truck looking for 'eaten' wires I started looking at lights. GOOD LUCK finding your problem.

Dave

 

[crash-harris]

IIRC, brake switch is non-adjustable. It's a cheap part, just replace it. It works off pressure. It's normal to have an inch or so of travel before the lights activate.

 

[dawgsfan08]

IIRC?

 

[madpogue]

The brake pedal switch does NOT work off pressure. The plunger simply moves when the pedal arm moves. Works just like the switch that turns on the light in your fridge.

To the OP - which "light" are you referring to in post #4?

IIRC - If I Recall Correctly

 

[crash-harris]

Hmm, you learn something new everyday. I thought the brake switch worked off pressure in some regard since I've always seen them have travel before the lights kick. On/off only, yes, but I thought they were pressure activate. When Bruiser had spongy brakes, after a few pumps (when the pedal firmed up) the lights would activate more quickly

I think he was talking about the brake lights in the taillight housings.

 

[dawgsfan08]

No light specifically. All lights work. Flashers work no problem. But when I flip blinker to right, it blows fuse

 

[madpogue]

So if the lights actually work with the flashers, unfortunately that puts the focus more on the signal switch in the column. Still, check for chafed wiring as suggested above, and start with removing the bulbs as mentioned.

 

[crash-harris]

Time to pull the steering wheel. I've had this happen before too. Someone was probably in there at some point and didn't bother to make sure the wires were laying flat and where they should.