Backing out of Dear Daughter's over Christmas... noticed lack of back up lights. (Driver's side out, passenger's came on... though it was still pretty dark backing out of her driveway.) I have a whole bin of bulbs... nope, not the right type. Off to the store I go. I buy # 3156... thinking single function backup lamps would be single filament. The lamps that came out are dual filament # 3157s. Well, I'd grabbed some spare # 3157s at the store, off the next peg, so I stuck them in... but I'm still scratching my head... Are these normally # 3157s or # 3156s? I'm trying to test the removed bulbs... look good... but it's like trying to hang onto a greased eel. (And, yes, again my bad fingers are a problem.) Thanks guys!I managed to test the old bulbs with my multi-meter... both filments test good in both bulbs Sooo I'm guessing that I have dirty sockets. It's snowing hard out there now... will check when it's not.

I have one light out on my 2000 Ram but even when it is working it leaves much to be desired.I also changed the bulb but still no light. Will be interested in what you find. I added auxilary backup lights on my 2005 Ram and I can see real good now.

I actually thought my back up lights were pretty good until they weren't. I've used 'tuner cleaner' plenty on electronics but think the results are short lived. I think the chemical cleaner allows contacts to oxidize quickly. With trailer plugs, I use an old ignition file & emery paper. I think with this I'll try scotch pad pieces & that file first. I don't know if some dielectric grease would be good or bad.Still snowing...

According to the manual, they should be 3157's.

EXTERIOR LAMPS

LAMP BULB

Back-up 3157

Cargo 921

Center High Mounted

Stop

921

Clearance Roof Mounted 168

Fog Lamps 896

Headlamp - SLT 9004LL

Headlamp - Sport Low

Beam

9007

Headlamp - Sport High

Beam

9004LL

License Plate w/o

Bumper

1155

License Plate -Step

Bumper

168

Park/Turn Signal 3157NA

Snow Plow Control 161

Tail/Brake/Turn Signal 3157

Tail/Brake/Cab - Chassis 1157

Underhood 105

Mine had 3157's in them. I changed them out for the RetroSolutions LED backup lights bulbs. Much brighter now. Ended up putting one of the old backup bulbs in as a turn signal bulb later. One advantage of them being the same (3157).

I haven't followed up on this... I'm down sick. Bad cold or maybe flu? I just have to survive this. Interesting that the same bulbs are used.

Hmmm... As for the bulb sockets I would use a dab of dielectric grease and fresh bulbs and see what happens. But even in my truck the stock backup light are nearly worthless. You all know I added a pair of 100w floods to my rear axle.

I replaced the bulbs & didn't fix the problem. The bulbs that came out tested ok, too. Some of the contacts looked dark & oxidized. As soon as I'm fit to go outdoors, I'm planning to use a 3M pad around a thin file to clean up the contacts & try again. I picked up a pair of Silverstar 3157's... wonder if I'd like them, assuming I can get them lit!When backing at night, I'm used to dropping to parking lights which helps my eyes adjust to the rear light... This cold or whatever is hanging on. At least I'm not on the immune suppressing MS treatment anymore. (Any infection, cold or flu... upregulates the immune system & makes MS symptoms very much worse... Can't say much more without engaging the word censor!)