1994 Class A chassis electrical issue

[bullfrog]

We need to make sure we a testing the correct sockets, the socket in your hand in the picture has continuity between the metal where the light bulb locking pins secure the bulb and the frame correct?

 

[Rhianntp]

Correct..all the sockets do

 

[bullfrog]

One of the pins in the bottom of the socket should have 12 volts with the running lights on does it?

 

[Rhianntp]

With the running lights on all pins in all sockets as well as the neg points show 11.56 volts

 

[Rhianntp]

When I say all sockets I mean both brake/tail light assembly as well as the 3rd brake light

 

[bullfrog]

You are telling me even the outside metal of the socket has 11.56 volts and both of the pins in the bottom of the socket that are in plastic insulation have 11.56 volts also? In other words all three wires even the one that goes to ground reads 11.56 volts? Sorry for the slow reply. You are confusing the issue by checking all the sockets lets just deal with the one socket in your hand. I understand you have continuity between the metal in the socket and the frame right? Now do you have 12 volts on one of the pins in the bottom of the socket and 0 volts on the other with the running lights on?

 

[Rhianntp]

You are telling me even the outside metal of the socket has 11.56 volts and both of the pins in the bottom of the socket that are in plastic insulation have 11.56 volts also? In other words all three wires even the one that goes to ground reads 11.56 volts?

Yes

 

[Rhianntp]

On all three sockets and the license plate light wires

 

[bullfrog]

I get confused easily and my internet isn't helping as it is slow. Forget the other sockets let's deal with only the one in your hand in the picture as I think I know what to look for on that one. You have continuity between the metal housing in the socket and the frame right?

 

[Rhianntp]

Yes

 

[Rhianntp]

I get confused easily and my internet isn't helping as it is slow. Forget the other sockets let's deal with only the one in your hand in the picture as I think I know what to look for on that one. You have continuity between the metal housing in the socket and the frame right?

The socket in the picture has continuity between the neg part and the clean frame ground... when the running lights are turned on both points inside and the neg part all read 11.56 volts and no bulb put in it lights up

 

[bullfrog]

Okay so now set the meter to 12 volts DC and turn on the running lights. Check the two pins in the bottom of the socket individually and tell me what you get.

 

[bullfrog]

Okay again because of slow internet my reply was being typed as you sent your last post. So you are telling me you have a good ground to the frame from the socket and both pins in the bottom of the socket that are in the plastic insulation and the metal housing which is grounded to the frame have 11.56 volts DC on them when the running lights are on?

 

[Rhianntp]

exactly

 

[Rhianntp]

If I bypass the socket completely and probe the equivalent wire nuts the results are the same

 

[bullfrog]

Okay to verify as this is a really unusual, You still have the black lead of the meter attached as in the picture and with the running lights on using the red lead you are reading 11.56 volts on both bottom pins and the metal housing in the socket that secures the bulb correct?

 

[Rhianntp]

yes.. black probe on the clean metal ground.. red probe to those points

 

[Rhianntp]

When I press the brake pedal with the running lights switched off they all light up.. dimly..

 

[bullfrog]

Wow, that is crazy. The bulb will not light because it's ground has 11.56 volts that is apparently not able to get back to the negative post on the battery. You should not even be able to get a reading if everything has battery power which is confusing because it would be like putting both the black and red probes on the positive post of the battery no differential no voltage. You would think something would burn with the frame reading 11.56 volts. Go to the starting battery and put the meter to measure 12 volts. Put the red lead on the shinny metal frame and the black lead on the center of the center of the negative lead post of the battery with the running lights on and see if you get a voltage reading. Let me know what it is.

 

[Rhianntp]

I haven't seen 11.56 volts on any frame point.. just inside the sockets / on the wires