Headlights aren't working. Fuses Ok, relay under hood OK. Bulbs OK where else should I look before replacing the switch on the steering wheel column?
Thanks,


Bob

 

1. Does high beam work?

2. If low beam bulbs and fuses are okay, try this:

Unplug the combo switch harness connector on the steering column. With a spare piece of wire of small paper clip, jump terminal cavity number 4 to terminal cavity number 11. (Double check the wire colors and terminal numbers, female side connector terminal numbering is from the wire side.) Does the headlights turn on? If they do, the switch is probably the issue.

If it doesn't turn on with by jumping terminal number 4 to terminal number 11; then instead of jumping to terminal number 11, touch that end to chassis ground (bare metal bracket, etc.). You may need to use a longer wire for this. Does it turn on now?

 

OK, I give a try tomorrow. No high beams are off also.


Bob

 

Redbull,
We have some distractions today so I probably won't get to this until tomorrow, but I have a question about the connector. Is pin 11 a connection to ground? I'm guessing from the G401 label. So all the circuits are completed by the switch making a connection to ground? Can I test the high beam systems by connecting 10 to 11?


Again thanks,
Bob

 

Pin 11 is a connection to ground (G401). To test the high beams, you can connect pin 11 to pin 10; however, pin 4 would also need to be connected to ground at the same time.

Ground (-) going through the pin 4 (Blu/Red wire) is needed to energize both headlight relay coils; so the respective relays will close to provide power (+) on the bulb side. (The relays are normally open.)

 

Redbull,


Connector diagram says #10 is high beams and 12 is left turn signal? I can rig a connector to do both 4 and 12 (10?)


Bob

 

I had a typo, it should say 10 instead of 12.

 

Redbull,
I did the jumpers still now lights. I checked the resistance from 11 to ground and it's <.001 so that wire seems to be OK. I measured #4 with ignition on and I get 9 volts. The battery shows ~12 without the alternator and the alternator shows 14.35 so I'm thinking they're all OK. Turn signals are all working so I'm guessing 12, 13, 14 are all OK. BTW what does the #7 Lights ON output control? I checked the wire from the fuse box to the left light and that's OK. I measure the resistance across the relay coil and that was 88 which is reasonable. Then I measured the pins the coil plugs into and with the ignition on and light switch on both were 12 V. Not sure why both were 12 V I would think one side would be at ground. We also swapped all the relays with the AC relays and that didn't change anything and the AC worked fine with the light relays. What do you suggest I measure next?
Bob

 

I'd start with the simple stuff first. Unplug the low beam bulbs. Use your volt meter to measure for voltage on the red/yel then the red/grn wires. Use a good ground (like the - battery post) as your ground. Do you see voltage on those wires with the headlights turned on?

Both relays have four pins. If you look at the relay, two pins should have thicker metal (that may be copper). This is for the power side of the relay. Two pins will be smaller cheaper metal and this is for the low voltage control side.

For each relay, a control and a power pin will have 12V at all times. The other power pin will be connected to the red/X wire to the bulb, the last pin will be on the control side and will get ground to turn on the relay.

I suspect that you are not getting a ground signal to this pin, but you need to test first.

 

Are these the wires at the steering column switch? I think I checked that on the relay. Looks as if the coil (control) pins are on the back portion of the socket since I got ~80 ohms across those on the relay. When I measured the voltage at the socket (female portion) switch on, I found 12 V on both while I expected to get ground on one of them. I did use the battery -. However I did have the bulbs connected. I'm going to get to the library tomorrow and check out a wiring diagram before I jump into this again.
Bob