Another headlight question
Thread Starter
Drifting
Joined: Nov 2013
Posts: 1,546
Likes: 281
From: Scottsdale Arizona
Another headlight question
I'm trying to get the headlights working on my 68 and came across what I believe to be a problem with the actuators. I've read all the troubleshooting threads and can't find an answer. All the vacuum lines are new and run according to the AIM. When I pull the headlight switch or use the override switch nothing happens. I'm pretty sure the tank is ok because after I shut it off and pull the headlight switch I can hear the relay working. I did find one seal torn on the front of the right actuator so I know that needs attention. The left one seems ok and holds vacuum when I tested it with the mightyvac. Since the relay functions correctly when the switch is pulled and nothing happens, could it be that I need to repair or replace the actuators? Any help with this will be greatly appreciated. Thanks in advance.
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
Since you have a hand vacuum pump the headlight vacuum actuators are very easy to check. You need to check both (front and rear) vacuum connections. A leak ONLY at the front connector means that the shaft seal needs to be replaced. The parts to do so are readily available. A leak at the rear means that the main diaphragm is faulty and the actuator needs to be replaced. While both sides should hold vacuum indefinitely a slow leak won't prevent them from operating. The front connection works to open the headlamp door; the rear one closes it.
Thread Starter
Drifting
Joined: Nov 2013
Posts: 1,546
Likes: 281
From: Scottsdale Arizona
Since you have a hand vacuum pump the headlight vacuum actuators are very easy to check. You need to check both (front and rear) vacuum connections. A leak ONLY at the front connector means that the shaft seal needs to be replaced. The parts to do so are readily available. A leak at the rear means that the main diaphragm is faulty and the actuator needs to be replaced. While both sides should hold vacuum indefinitely a slow leak won't prevent them from operating. The front connection works to open the headlamp door; the rear one closes it.
I checked them with the vacuum pump and both have a slow leak at the rear ports. The left one leaks a little at the front port and the right will not hold vacuum at all. As for my connections, I followed the diagram that came with the new hose kit and I double checked with the AIM. Looks like I'll be buying new actuators. Thanks guys.
