83 242 No High Beams

On my 83 242, I'm having an issue with the high beams. Low beams work fine, but High Beams dont work at all. When I pull the stalk, the step relay under the hood clicks, but the lights do not switch and the highbeams do not flash. I have tested the step relay (as well as another one), and it checks out according to the info on Dave's page. I have verified power to pin 56 on the relay from the headlight switch and the momentary ground on pin 31b from the stalk. Jumping power to pin 56a powers the highbeams and low beams, and jumping 12v to 56b powers the low beams.

Where should I look next?

Have you checked whether your bulbs actually work?

Just replaced them. Jumping 12v to 56a powers on all the headlights.

Also, verified 12 volts from the battery at pins 15 and 81a.

Those Power Probes dump a lot of power into a component. Have you checked that the power is actually getting to the relay? Using a test lamp, NOT a meter.

There's a mechanical toggle that switches the current between 56a and 56b. On old relays the toggle can stick on it's pivot pin. Take the cover off and activate the relay to see if it's stuck.

Great suggestion. ^

I like to pop the cover off relays and pinch them closed and see if the component activates. That way, you have also confirmed the input and output circuits are OK too.

ZVOLV said:

Those Power Probes dump a lot of power into a component. Have you checked that the power is actually getting to the relay? Using a test lamp, NOT a meter.

Click to expand...

Good call. I used a test light and confirmed power to all positions. I hooked the test light to the positive and tested the ground signal from the column to the relay and it barely glowed.

I think its getting enough ground to attempt to switch hence the noise from the relay. I shot a ground to the relay using the power probe and it switches great and locks in. I believe in dealing with a dirty ground issue, or a dirty ground combined with a stiff relay as hiperfauto has suggested below.

hiperfauto said:

There's a mechanical toggle that switches the current between 56a and 56b. On old relays the toggle can stick on it's pivot pin. Take the cover off and activate the relay to see if it's stuck.

Click to expand...

Problem solved.

Today I tested all the grounds from the battery to the steering column including the ones on the left side of the lower dash. All were .3 ohms or less. I pulled the steering column cover and tested terminal 31b which is the pin that sends the ground signal to the step relay. the average reading was around 65 ohms when I pulled the stalk. I removed the switch and bench tested it then flushed it with contact cleaner. Readings are now down to around 20 ohms after cleaning the switch. I would have disassembled it, but the cast part of the switch had a couple pins that have been rolled over and I would have needed to drill and tap some screw hole to reassemble it. The highbeams now work as intended.

Thanks to all for the help.