1990 Ford Bronco Brake Lights not working - stumped - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

FunDan · 06-03-2006, 11:59

Thanks in advance for reading this and hopefully helping me solve this.

I have (really my wife has) a 1990 Ford Bronco 4x4 5.8L on which the brake lights are not working. In trying to diagnose the problem, we also found the rear hazards and cruise control are not working. Checked the fuse, brake pedal switch and bulbs...all are good. Tail lights and turn signals do work as do the front hazard and dash hazard indicator (left-right directional indicators).

Well, I am stumped! Checked the wiring diagram for a relay, but don't see one that all three above systems might use. Anyone have any ideas of where a relay(es) I might check or any other ideas on what has caused this problem.

Also, the sterring column and driver-side window motor was replaced recently. However, we are not sure if the problem existed before before replacements. Other than that, nothing has been changed or tampered with.

Again, thanks in advance.

Aussiblue · 06-03-2006, 20:20

I would strt by checking all the wiring harnesses on and adjacent to the steering column are correctly and fully plugged in.

FunDan · 06-04-2006, 10:09

Kudos to you Aussiblue! Yes, the connectors were all plugged in tightly. But, from what you wrote I had a wild idea to hook up the old steering column by laying it on the floor board and connecting the cresent shaped connector. I wasn't sure anything would work that way. Buy, viola, everything worked as well as the brake lights etc. So, I guess I need to take advantage of the warranty on the steering column.

Apparently, the brake lights and rear hazards are 'controlled/monitored' via wiring thru the column. What the rationale or engineering behind it, I do not know. But, with an old chevy I had, I could tell a rear brake light was out when the gauge lights would go out.

Aussiblue · 06-04-2006, 18:41

Quote:

Apparently, the brake lights and rear hazards are 'controlled/monitored' via wiring thru the column. What the rationale or engineering behind it, I do not know

Most modern cars are wired this way. Probably for purposes of reduced cost, ease of factory assembly (i.e one harness for engine bay front lights etc, one for dash and control boxes, one for steering columna and light controls and one for rear body tail lights etc.) and reduced assembly failure (whole harness is checked as a unit before assembly and number of harness connectors are reduced). They seem more reliable made this way but the biggest problem is that if one plug fails or part of the harness is damaged you have to buy the whole expensive thing.

Aussiblue · 06-04-2006, 18:51

PS did you open up the old column to see if there are any harness plugs inside? If so they might be unplugged on the new one. There is also often an earth connection on steering columns (grounded black wire) that may be loose.