W900A Auto Reset Breakers

Greetings all, I have 2 W900A Kenworths one is a 79 Extended hood 60" Flat top sleeper on newer pete air leaf, DS402s, (7FB)3406BATAAC Hopped up, with a fuller 9 and a spicer 1241D aux, Second truck is an 81 with a 12 yard dump bed, double framed DS380s on Walking Beam, Cummins BCII400 (soon to be a (4MG) 3406B (JWAC) with a 14610 Super 10 and 1241D aux. Both of these trucks are experiencing the same issue, the 79EXHD has never had a problem with the headlight breaker tripping until I installed a new set of projector headlights, the 81 has been tripping with the factory halogens and the new projector headlights. Both trucks when the Trailer/Cab light switch is on will intermittently short and kill power to the tachometer (not completely still reads 200RPM or so) the 79 will also kill the backlights to the speedo and tach, Its kind of strange both trucks experience the same issue in that area, Now both trucks will trip the headlight breaker with the high beams on after about 5 minutes which I am hoping the breakers are just old and weak which the 79 has all new wiring to the headlights and I cant find any symptoms that would suggest a short, (hot wires, large draw etc.) Does anyone have any experience with these breakers getting weak or anything related to these issues?? Thanks in advance: Josh

 

Hey A Car thanks, I kinda figured that to be part of it for the headlights, I really wish I could see a schematic and figure out the Trailer line part and why the Tach pulls power from that area of the circuitry and why it doesnt effect anything else, it doesnt trip the trailer breaker all the lights stay on except the speedo and tack backlights and the tach signal or power (reads 200RPM) and both trucks have the same issue for this part of it, Im pretty sure the headlights are weak breakers, is there a higher amp one available?? Off topic speakin of A Cars we run a few of them that were retired from the oil field and we set them up as log trucks, the below photo is a 78 i believe AT64 with a BCI 400, 12515 with a 8341G Aux, SSHD Walking Beam and Triple Framed with a big load of burnt ponderosa; Thanks for the reply: Josh

 

Ok thanks for the info, Yeah thats going to be a problem for sure and finding a diagram isnt going to be easy, Was hopin to find a guru thats spent some time under the dash of the ol A models that might have an idea where to look. Thanks again for the help, and yeah sheas a good ol beast, moved a lot of timber for us over the years.

 

So does anyone happen to know part numbers for these breakers? And possibly where I can get them from? Thanks: Josh