Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



Visit the new site at vcca.org

Previous Thread
Next Thread
Print Thread
Rate Thread
#56962 12/08/05 11:56 PM
Joined: Sep 2005
Posts: 12
Grease Monkey
OP Offline
Grease Monkey
Joined: Sep 2005
Posts: 12
The resistor on the back of my headlamp switch is burnt out, which means I can't use low beam. Now I don't think I'll ever really have the need to use low beam since high beam is already low enough (!), but are these resistors available, or if not, does anyone know if a modern substitute can be used? From what I hear, the resistance has to be just right to ensure the correct headlamp power is achieved AND that the back of the switch doesn't get too hot.

Any advice?

Filling Station - Chevrolet & GMC Reproduction Parts


Filling Station


#56963 12/10/05 04:01 AM
Joined: Jan 2002
Posts: 812
Likes: 13
Lou Offline
ChatMaster - 750
Offline
ChatMaster - 750
Joined: Jan 2002
Posts: 812
Likes: 13
Maybe someone could check the ohms on their resistor then Martin could get one and silver soldier it in.

#56964 12/10/05 06:58 PM
Joined: Dec 2001
Posts: 217
Backyard Mechanic
Offline
Backyard Mechanic
Joined: Dec 2001
Posts: 217
Ask and you shall receive. Cold resistance is useless so you have to measure the resistor under load. According to my equipment, the resistor on my 28 coupe headlight switch drops 2.7 volts and the current through the circuit is 5.4 amps. According to Ohm's law, this works out to 0.5 ohms of resistance. The resistor also dissipates 14.6 watts of power which means it will get rather warm. If you wanted to replace with a modern equivalent, I would recommend a 0.5 ohm 30 watt resistor. You could connect two 1 ohm 20 watt resistors in parallel. (You want about 2x power rating as a safety margin). cool

Best regards,
Ron

#56965 12/11/05 10:11 AM
Joined: Apr 2002
Posts: 291
Backyard Mechanic
Offline
Backyard Mechanic
Joined: Apr 2002
Posts: 291
I found this on Ebay:
40 watt 0.5 ohm resistor

Dan.


Together we can do anything. The impossible just takes longer.
#56966 12/11/05 11:03 PM
Joined: Dec 2001
Posts: 11,162
ChatMaster - 10,000
Offline
ChatMaster - 10,000
Joined: Dec 2001
Posts: 11,162
The resistor that Billy Barker uses in his replacement heater switches may be usable for the dimmer resistor in the pre 29 headlight switch, I have no knowledge of it's value and specs, but the function is probably close to what is needed to dim the headlights.


Life's a long winding trail, love Jesus and ride a good horse!
#56967 12/12/05 07:12 PM
Joined: Apr 2002
Posts: 3,542
xxx Offline
ChatMaster - 3,000
Offline
ChatMaster - 3,000
Joined: Apr 2002
Posts: 3,542
The ebay auction is for 30 units? If that is what it is then I think the winner should have enough. LOL

bigl bigl bigl

#56968 12/15/05 06:49 PM
Joined: Sep 2005
Posts: 12
Grease Monkey
OP Offline
Grease Monkey
Joined: Sep 2005
Posts: 12
What a great bunch of Chev Nuts this group is! Thanks for all your help people, and especially to RustyFender for doing those measurements!

#56969 12/29/05 07:03 PM
Joined: Sep 2005
Posts: 12
Grease Monkey
OP Offline
Grease Monkey
Joined: Sep 2005
Posts: 12
Post Script: A kind soul from NSW Australia emailed me privately to ask if I wanted him to go through his spare parts bucket to look for one of these original resistors. I have accidentally deleted the email, so if you are reading this, please get back in touch, as the answer is YES! Thanks.


Link Copied to Clipboard
 

Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA.

Powered by UBB.threads™ PHP Forum Software 7.7.5