Dim Head Lights--WBB GP9

[GTBob]

Finally got around to trying out my new WBB Rock Island GP9 loco.  Everything appears to be operating properly EXCEPT the head lights (front & rear).  At about 10 volts to the track the lights are extremely dim.   I'm at a loss to explain why...
I have a WBB GP38 loco and a WBW FP45 loco that both exhibit very bright head lights w/ 10 volts to the track.  It's almost like the GP9 has 18 volt bulbs??

Does anyone out there know what voltage light bulbs should be used in the WBW diesel locos??  I'm sure they must all take the same bulb.  Any help regarding my problem would be appreciated.  Thanks.

Bob

[phillyreading]

Bob,

Look at the light bulb and see what it is. Should be a 9 or 12 volt light bulb in there, anything smaller than 9 volts may get too hot & melt the plastic.

Don't know for sure where to get 12 volt bulbs, most likely at a hobby shop, but Radio Shack sells 14.8 volt bulbs.

Lee F.

[DominicMazoch]

I think WBB sends extra bulbs with the loco.

[GTBob]

Philly--Bulbs are 12V.

Dom--Yes, extra bulbs are 12V, just like loco.


I switched bulbs from FP45 to GP9.  GP9 still has dimmer lights.   Original GP9 bulbs are now bright when used on FP45....

I've got to look a little deeper into this and try to come up w/ an answer....It sure looks like a locomotive problem and not a bulb problem?

[Joe Satnik]

Dear Bob,

Track voltage to 10 volts, loco in neutral. 

Remove a bulb in the GP9 and measure the voltage in the socket. 

Did the other light remain the same brightness?

Replace the bulb, then remove the other and measure the voltage in its socket. 

Change in brightness in the replaced bulb when other removed?

Remove both bulbs, measure voltage in both sockets.

Both bulbs in, measure voltage between each bulb socket base and the chassis.  (Should be zero.)

Follow and trace lighting wiring and compare to FP45. 

Let us know.

Sincerely,

Joe Satnik

[GTBob]

Joe---Great idea.....

Will let you know results once known.

Bob

[SantaFe158]

I'm having the same problem with my N&W J class, it's a constant voltage circuit, and I think mine has a 12v bulb.

[Joe Satnik]

In general, constant voltage circuits feed lower voltage bulbs.

It could be in a Williams/WBB, but it is new to me if it is.

Hope this helps.

Sincerely,

Joe Satnik  

Edit: spelling

[GTBob]

Joe---Great idea.....

Will let you know results once known.

Bob

Joe---think I've got it figured out?

Put GP9 on track w/ 10.0v.  Both sockets read 10.0v when tested individually.  There was no change in bulb brightness when either bulb was removed. 

Put FP45 on track w/10v.  Front bulb socket measured 9.8v and rear bulb socket measured 9.6v when tested individually.  There was no noticeable bulb brightness in either bulb.  Remember--this is the loco w/ brighter bulbs.


Hmmmm---what gives here???  This is what I found----The GP9 runs on a smaller i/s loop w/ 5 freight cars including a MTH lighted caboose.  The FP45 runs on a larger o/s loop w/ 4 brightly lit MTH 027 passenger cars.  When measuring the track voltage while each train is running at normal speed the results are: GP9 w/ cars--8.1v---FP45 w/ lighted pass cars 10.1v.  I don't know why there are 2 volts difference between each loop, but, this accounts for the brighter bulbs on the FP45 vs. GP9.  I tried running the GP9 at 10 volts and thought the thing was going self distruct(fly off the track), so I backed off.  I guess the last thing to do is to try the GP9 on the larger o/s track w/ lighted pass cars and evaluate the loco's bulb brightness.

At this point, I don't think it's a problem w/ the GP9.

[Joe Satnik]

Well, Bob,

To slow things down and brighten things up, you could wire the 2 motors in series, (factory stock has motors wired in parallel), or, like Roger (RNF), put in a 3 amp DPDT switch to make it switchable between the two:

http://www.bachmanntrains.com/home-usa/board/index.php/topic,14649.0.html

If you wanted to keep your factory warranty, I suppose you could build a removable "series adapter harness" out of wire and molex connectors ...

Hope this helps.

Sincerely,

Joe Satnik