I'm going to rule out the grounds as a very unlikely problem source. There are two grounds, one on each side for the headlamps. So in theory, it would be very unlikely both went out at the same time.
The switch to the headlights has a built in circuit breaker which may be hosing up. Unlikely, but a new switch MIGHT help. But here's the rub. You have to have the headlamp switch ON to get the high beam light. Meaning the switch and circuit breaker needs to work.
While the blue light is on indicating high beams, click the high beams and see if the light goes off. It should. Meaning the dimmer switch may be working correctly. If it's NOT, it might be the dimmer switch itself.
There's a rod going down to the dimmer switch along the left side of the column (when sitting in driver seat). The switch itself is located right behind where the left side bolt holds the column to the dash. The rod might fall out if you remove the switch, so if you change it out, just tape it to the column. 2 small screw heads (7 or 8 mm I think?) like sheet metal screws hold it on to the ignition switch that sits on top of the column. 7838234 is the GM number for the switch. Standard Motor Products has it as DS79. There are likely others. They are not too pricey. But a bit of a PITA to replace just because of where it is located.
Here's what the switch looks like when viewed from the left side of the column. OEM is similar in appearance, but hooks up the same way. The rod from the dimmer actuator inside the column fits in the RH end of the white plastic shown below.
There is a C100 connection for the headlights coming out of the dimmer switch that's located on the connectors coming out of the firewall under the wiper motor. TOUGH to get to. Unlikely it's this connector.
There's a yellow wire coming from the headlamp switch that goes to the dimmer switch on the column. The other two prongs have tan (low beam) and green (high beam). If you pull the plug on the dimmer switch and use a jumper wire to connect the yellow to the tan and then the green, you can test to see if your headlamp dash switch is working, and if the dimmer switch is bad at the same time. Once you put the jumper from the yellow wire connection to either tan or green, then turn the headlamp switch on briefly and see if the headlamps come on. If they do, it's the dimmer switch. If they don't, it's likely the headlamp switch or a bad section of wiring from the headlight switch all the way to the lamps somewhere. The odd part is that when the high beam switch is on, then the high beam indicator on the dash lights up. This is before that firewall connection point C100.
I'm not an electrician, but you have to get power to the lamps and this dimmer switch is a key component. Without it, you won't have low or high beams.
The switch to the headlights has a built in circuit breaker which may be hosing up. Unlikely, but a new switch MIGHT help. But here's the rub. You have to have the headlamp switch ON to get the high beam light. Meaning the switch and circuit breaker needs to work.
While the blue light is on indicating high beams, click the high beams and see if the light goes off. It should. Meaning the dimmer switch may be working correctly. If it's NOT, it might be the dimmer switch itself.
There's a rod going down to the dimmer switch along the left side of the column (when sitting in driver seat). The switch itself is located right behind where the left side bolt holds the column to the dash. The rod might fall out if you remove the switch, so if you change it out, just tape it to the column. 2 small screw heads (7 or 8 mm I think?) like sheet metal screws hold it on to the ignition switch that sits on top of the column. 7838234 is the GM number for the switch. Standard Motor Products has it as DS79. There are likely others. They are not too pricey. But a bit of a PITA to replace just because of where it is located.
Here's what the switch looks like when viewed from the left side of the column. OEM is similar in appearance, but hooks up the same way. The rod from the dimmer actuator inside the column fits in the RH end of the white plastic shown below.
There is a C100 connection for the headlights coming out of the dimmer switch that's located on the connectors coming out of the firewall under the wiper motor. TOUGH to get to. Unlikely it's this connector.
There's a yellow wire coming from the headlamp switch that goes to the dimmer switch on the column. The other two prongs have tan (low beam) and green (high beam). If you pull the plug on the dimmer switch and use a jumper wire to connect the yellow to the tan and then the green, you can test to see if your headlamp dash switch is working, and if the dimmer switch is bad at the same time. Once you put the jumper from the yellow wire connection to either tan or green, then turn the headlamp switch on briefly and see if the headlamps come on. If they do, it's the dimmer switch. If they don't, it's likely the headlamp switch or a bad section of wiring from the headlight switch all the way to the lamps somewhere. The odd part is that when the high beam switch is on, then the high beam indicator on the dash lights up. This is before that firewall connection point C100.
I'm not an electrician, but you have to get power to the lamps and this dimmer switch is a key component. Without it, you won't have low or high beams.
