Electrical problem on foxbody

NYSpeed Automotive
1

Ok a few days ago my check engine light and oil light came on and the blinkers don’t work, and my air doesn’t work. A few days later it stopped then I’d turn it off then back on and then the shit doesn’t work anymore.

I checked fuses and they’re all good. I’m going to check all my grounds but I don’t think thats the problem.

Any and all help is greatly appreciated.

Car is 91 Mustang LX

Thanks.

2

ah geez. ford wiring. sounds like a relay to me though.

3

I do have a general repair manual for 89 fords in general, according to it fuses 5#, and 9# control the blower, and turn signals. Checking it with autozone’s shitty schematics the fuse/wiring layout looks to be the same for that circuit.

Both are driven off one wire in the back of the fuse panel, also looks like it would control your rear window defoggers so see if you lost that also. According to my book it’s a grey-yellow wire run off the ignition switch, however they did change a lot around in 91 so it may be different in terms of color. But I would check that wire, and the ignition switch first.

Test it as follows:

  1. Put key in on position
  2. Test fuse holder #5 and #9 for power you should be getting +12VDC there. Chances are if neither are working there is nothing or very little.
  3. If there is no power, trace the wire to the ignition switch
  4. Turn ignition off
  5. Trace wire from fuse panel to the ignition switch
  6. Unplug battery negative terminal
  7. Pull harness from ignition switch, and test from harness connector, to fuse holder #5

8a. If there is no conductivity, might be a bad/melted wire or loose connector at the ignition plug, or fuse panel try to narrow down bad section and solder a new section in or resolder the connector. And be done with it, or…
8b. If there is conductivity, then proceed to check the ignition switch by plugging the harness back in

9.There should be a bit of exposed contact in the back of the harness you can test from. Hook you voltmeter up there
10. Reconnect battery
11. Test for power, if there is no power then it might be a bad ignition switch.

Though there is more to test if the above doesn’t work that will narrow it down. As for the CEL/oil pressure lights, I have a feeling that is just something else that happened to occur around the same time unless the ignition wiring melted.

4

:inb4BDR5OH:…there might be a main relat to control all of those under the hood…either that or some serious wiring issues behind the dash

5

:word:

If anyone knows it would be him.

6

bump What’s the status of this?

7

i had a really busy day at work but im gonna dig up my voltometer and test this today

thanks fuzzy :tup: