Peterbilt 378 Reverse light/horn

I had this problem with my 378 and it ended up being the reverse light sender on the top of the trans...RTLO16918B, but I'll assume all Eatons are the same. I tried and tried to find the problem via the wiring but ended up pulling the plug off the sender on the trans, jumped it across with a hot wire from the battery and it worked....so the sender was bad. It takes a skinny guy and I think a 7/8" wrench (IIRC) to get the sender out.

 

Had no back-up lights in my 98' 379, found out that it was a bad back-up light switch on top of transmission.

 

where are you hooking in to put power to the light?

it could be a broken wire..........someplace

 

I realize this is an older thread, so thank you in advance, when I put the trans in reverse, I pop the acc switch @ the fuse panel. Would this be the reverse switch also? I have check the wiring to the reverse lights for corrosion. All seems goods. Gonna tackle this super fun project little by little these next couple of days.

 

If you pull the plastic cover where the shifter comes up through the floor, the switch is right there. Easier and cleaner than crawling underneath. I would take the switch to an auto parts store instead of Peterbilt. Same switch, cheaper price. Pollack part # for Eaton transmissions with metri-pack end is 21-635-P.
http://www.peterbiltparts.com/elect...oem-breakers-relays-senders-switches/21-635p/

 

Ok. Pulled the cover and swapped out the switch. Problem solved. No more popped fuses. Thank goodness. $12.79 at Peterbilt. Part # 21-465P is correct. Awesome. So I bought a(another) Peterbilt ballcap.

 

Dang. I must not read to well. I thought you typed 465, but it reads 635. Well, I got a 21-465P & it works. Yet, all I asked for was a reverse switch. Thank you anyhow.

 

Hey fellas. I have a question. I too had the same problem and i replaced the switch with 21-635p but every few weeks i have to replace the switch. I called several dealerships and they are telling me they will charge me by the hour and there is no telling how many hours it will take. Any suggestions as to where to start on my own. Thanks in advance.