Ignition switch

[Ironred88]

I'm going to apologize for being kinda dumb here, but I can't seem to figure this out.I know it's all over the this forum, but I am electrically illiterate.

I seem to be loosing power going through the ignition. My park and dash lights work, but when I switch the headlights to on, all the lights go out. They used to work, and over time were less and less likely to turn on. The big brown wire, and the white connector on the back of the ignition switch is clean. Using a voltmeter, testing the headlight switch connector, I was getting 12v between the park lights and ground, but nothing between the blueand brown wires to the black wire, which I think goes directly to the headlights.

I'm at a loss here, is it possible that the ignition switch is wearing out and loosing contact? Also, I think the high/low beam switch is connected, but it doesn't seem to change anything no matter what position it is in.

[aj81spider]

It could be a bad headlight switch. According to the 78n wiring diagram I have (your profile says you have a 78) the light blue wire comes from the ignition switch. If it has 12 v then your ignition switch is likely OK. The green wire on the light switch goes to the high beam switch. Check that that has 12 volts when the headlights are on. If it doesn't then the switch is bad. If it does then check that either the blue or gray/red wire coming out of the high beam switch has power (depending on whether you are on high or low beams). If neither has 12 V then you have a bad high/low switch.

A convenient place to check them is at the fuse box. They go into fuse 3/4 and 5/6 (the two fuses are bridged together).

If they have power then make sure the fuses aren't blown. If power is coming out of the fuse then check at the headlight connector.

If the lights aren't coming on then something along that path is open. If you don't have the wiring diagrams you should get them - it's hard to debug wiring without them. I have a .jpg version of the 78 wiring. Not very convenient, but better than nothing. PM me if you don't have the wiring diagrams and you'd like me to email the ones I have.

[spider2081]

On my 81 Spider connections at the headlight switch are: Black wire is "hot all the time" and is power for the parking lights.
The light blue wire is "hot in start and run" and is power for the head lights. The brown wire in the same pin as the light blue is power for the high beam flash switch in the control column. when the headlight switch is on power is switched from the light blue wire to the green wire.
If you had no voltage at the light blue your ignition switch could be defective. Do your windshield washer and heater blower work? they use the same contact of the ignition switch.

The light blue wire is on the "int" terminal of ignition switch. It is powered from the brown wire on terminal 30 of the ignition switch in the "start and run" positions of the switch.

Hope this helps

[Ironred88]

Oh shoot, I don't know how, but I must have filled the profile out wrong, I have an 81 fuel injected! I don't know how much that changes. So power comes in from the brown wire, to the ignition switch, out the ignition switch in a blue wire, to the light switch to the high low then to the lights?

Also, I have a new headlight switch, because the old one was falling apart inside (I took it apart, the contacts were so worn that they didn't touch)

[aj81spider]

I have an 81 wiring diagram and the colors look like they are the same. After re-reading your post I'm not sure if the blue wire has power or not. However Spider 2081's description is correct.

I would start by checking that blue wire at the light switch to see if power is getting to the switch. If it is not then either your ignition switch is bad or there is an open wire/connector.

The INT position in the ignition switch also appears to drive the wipers so if there is no power at the headlight switch you can check if they work to see if power is getting through the ignition switch.

[Ironred88]

My windshield washer has never worked, but this morning the heater blower didn't work. Also, my wipers just click when they get turned on, but I just got them unstuck on Sunday, so I don't know if that's because of the ignition or because they are barely working.

So I kinda know where I need to look at tomorrow,checking for power out of the ignition switch, because it all seems to lead to that not working correctly.

[Ironred88]

alright, so ive traced it down to the ignition switch, i get twelve volts going in, and from .5-3 coming out, if i wiggle the key around. so im thinking thats the issue. so i guess i either have to rebuild or replace it. would electrical parts cleaner, just sprayed inside it help at all? maybe clean it up a bit so i could use it while i wait for a new one, or while i source those crazy small screws ill need to rebuild it? I found all the writeups for it, and i think i would rather reuse my old one if i can.

Thanks for your help guys!

[johnsje6]

I replaced the ignition switch on my '79 after mine failed, this one works great.

http://www.autoricambi.us/product/EL7-4 ... on-Switch/

[Ironred88]

Well, it looks like i will be buying a new one, upon opening the ignition switch, i realized that there are only two plastic pins, when there should be three, the one missing, is the one that operates the windshield wipers, and the headlights. i opened it up over a white table sheet, and nothing fell out. so i think someone has been in here before. time for a new one for now, keep the old just in case

[Ironred88]

New Ignition switch in from Autoricambi, and now everything works perfectly, my next project is to install headlight relays!
Thanks for the help guys!