Ignition Switch?

Topic: Ignition Switch? (Read 2564 times) previous topic - next topic

Ignition Switch?

August 19, 2005, 08:05:12 PM

Hey Everyone I need some help. Today when I got in the car to leave work I started it and the instrument cluster illuminates but there is no display. Also there is no display on the climate control. My turn signals stopped working also.

Everything else on the car works fine. I checked everything, including every fuse in the fuse panel. I'm thinking the problem may be the ignition switch. Can anyone confirm that? Please let me know. Thanks!

Re: Ignition Switch?

Reply #1 – August 19, 2005, 08:16:40 PM

Yes, it's your ignition switch. It happened in my 87 Sport and 88 T-Bird. A word of advice: Go out and disconnect your battery until you replace it - they've been known to catch fire even with the car unattended.

Re: Ignition Switch?

Reply #2 – August 19, 2005, 09:43:37 PM

So is this the steering colum fire thing that ive been finding every time i search for 1988 t-bird 5.0 ?

Z

Re: Ignition Switch?

Reply #3 – August 19, 2005, 10:03:04 PM

I just finished installing the new ignition switch. You could see on the harness plug where the grey wire with the yellow stripe had gotten really hot and partially melted the plug. It was not melted too bad to plug in the new switch so I went ahead and did that, re-installed the switch, connected the battery, and turned the key.

My instrument cluster lights came on again but now my turn signals burn solid whereas before they wouldn't light at all and there is still no display on the climate control although the blower comes on without me telling it to and all of the fuses look good.

There aren't any other wires in the dash harness that look bad or melted. In fact there wasn't any damage I could see beyond the aforementioned harness plug which seemed fairly minor.

Any ideas? Could it be that the bad ignition switched caused my turn signal switch to get fried? I have an EVTM but I'm afraid I don't know enough about electrical diagrams for it to be any huge amount of help.

Re: Ignition Switch?

Reply #4 – August 19, 2005, 10:08:47 PM

If your turn signals don't flash you either need a flasher or have a burned out bulb. The flasher is the more likely culprit (otherwise only one side wouldn't work). Get yourself a Tridon HD12 flasher for about eight bucks.

As for the climate control I don't have my EVTM handy so someone else'll have to help you through that...

One thing you might want to do is remove the ignition switch harness and look for signs of heating on the new switch terminals. Try wiggling the wires with the harness plugged in and the switch turned on and see if your climate control does anything. Your harness may not be making good contact, in which case you'll burn the new switch up in short order.

Re: Ignition Switch?

Reply #5 – August 19, 2005, 10:10:54 PM

One other thing I forgot to mention is that it seems that my battery is being drained now. As soon as I turn on the key I immediately start losing power and the car won't turn over. That was not a problem until I replaced the ignition switch.

Re: Ignition Switch?

Reply #6 – August 19, 2005, 10:15:20 PM

Try charging the battery. When your switch failed the alternator was not charging - it relies on the same circuit as the gauges to turn on and start charging. You drove the car home on the battery. The ignition switch has two "IGN" circuits - one with the items you mentioned on it, the other with the things required to run the car (EEC-IV, fuel pump relay, ign coil, etc). Only one of those circuits failed; luckily it was the good one, else you'd have been stranded.

This could be why your climate control isn't working as well - voltage too low to operate the ACC module

Re: Ignition Switch?

Reply #7 – August 21, 2005, 07:57:25 AM

Quote

the grey wire with the yellow stripe had gotten really hot

That's the one(s) that powers the O2 sensors, the instrument voltage regulator (for the gauges), and the alternator "kick start" via the dash bulb.

If the wire got really cooked, there could be a bad connection between the wire and the crimped terminal, the terminal could be coated with a thin layer of melted plastic, or the terminal metal itself could have chemically changed from the heat, to where it won't conduct properly.

Re: Ignition Switch?

Reply #8 – August 21, 2005, 05:47:33 PM

Sorry for the hijack, but while on the subject of the ignition switch: how do you remove it if it appears to have been riveted in place, vs. the star bits with the little posts in the middle? I have the proper star bits.. used them to change the switch on my Mark last night.. but I'm working on the '86 T-bird today, and it has these rivets in place. (there's also a Ford P/N on the switch.. looks like it has never been replaced) I tried drilling one of the little rivet balls out, but it's not doing anything. I *have* to replace this switch.. even 10+ minutes after disconnecting the battery, the switch is still uncomfortably hot to the touch. Car hasn't been used since the middle of the week.

(got the drilling part from the Haynes manual)

Re: Ignition Switch?

Reply #9 – August 21, 2005, 06:48:41 PM

The '86 has the shear off head screws, they are not rivits. Cut a slot into them, and they should just turn out. Or usually there is enough shoulder on them to lock on a small pair of vice grips...

Re: Ignition Switch?

Reply #10 – August 22, 2005, 12:23:31 AM

I got everything back together and the car starts again and runs great. Unfortunately the gauges module in my instrument cluster is dead. The speedometer and fuel computer both work fine but the section with the tach does not light up or display anything at all. I inspected the cluster and took that module completely apart and everything looks like it should work. There were no burnt traces and all of the ribbons and wires were fine. Could the intrument voltage regulator be the culprit even though 2/3 of the cluster is working okay? Or is it possible that the tach module was damaged?

Re: Ignition Switch?

Reply #11 – August 22, 2005, 10:44:22 AM

Upon close inspection on my way to work this morning I realized that the tachometer module is actually working but the backlight is not. I don't know if it just started working or if I just couldn't see it when I had it in the garage last night. In any case it definitely has a display but it just doesn't light up. Which is odd because I replaced all of the bulbs in the cluster when I had it out.