Jimjific 23 Report post Posted September 7, 2012 So my back up lights have never worked on my 69 since I got it. I finally decided to look at it the other day. I started with checking the bulbs. Hoping that they would be dead since this would be the easiest to debug. Well, the bulbs ring out on my meter, so they are ok. Then I noticed something odd. The bulb I had had one contact (1156) but the housing has two (1157) so when you screw it in it never makes contact. So I look up the housings and the bulbs from Mustangs Unlimited and they show a two contact housing and a one contact bulb for the back up lights. So, I guess I could put an 1157 bulb in but why would you want two filaments? I guess I'm just confused here. What bulbs do you guys use for back up lights? Thanks, Jim Quote Share this post Link to post Share on other sites
Mike65 476 Report post Posted September 7, 2012 I thought they were 1 contact 1156 bulbs so I checked in my NPD catalog on pg-181 is a light bulb guide & it says for the back up lights 1156 bulb. Quote Share this post Link to post Share on other sites
Jimjific 23 Report post Posted September 7, 2012 Yes, that is what Mustangs Unlimited shows too. But, the housings that I have and that they show are set up for a 1157 two contact bulb. I checked my housing for 12V and the one contact int the housing had 12V when I put the car in reverse. Jim Quote Share this post Link to post Share on other sites
Jimjific 23 Report post Posted September 7, 2012 I just noticed this note on Mustangs Unlimited site for their housing. *The housing is being made with a dual contact bulb socket and includes a bulb. Use #TL1142 as a replacement bulb. Problem solved. Now I will be able to drive in reverse at night. Thanks, Jim Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted September 7, 2012 I see a "Rockford" in your future!!! Bruce Quote Share this post Link to post Share on other sites
Jimjific 23 Report post Posted September 7, 2012 Man, as a kid (And a s a big kid now) I thought that was the coolest maneuver. Garner and McQueen were my favorite actors back then. Jim Quote Share this post Link to post Share on other sites
bobh67 18 Report post Posted September 7, 2012 I just noticed this note on Mustangs Unlimited site for their housing. *The housing is being made with a dual contact bulb socket and includes a bulb. Use #TL1142 as a replacement bulb. Problem solved. Now I will be able to drive in reverse at night. Thanks, Jim Just curious Does the #TL 1142 bulb have two contacts then?I take it that it does to mate with the 2 prong socket? Quote Share this post Link to post Share on other sites
Jimjific 23 Report post Posted September 7, 2012 I assume that, that is the case. I also assume that the "keying" feature will only let the bulb in one way so that the one contact that goes hot in reverse will match the filament. I went to NAPA after work and the only had 1141 bulbs. They only have one contact. So I will have to try somewhere else. I wonder why they design the aftermarket housing to not use a single contact. Jim Quote Share this post Link to post Share on other sites
Pakrat 1,043 Report post Posted September 8, 2012 I feel like I am missing something important to this conversation, how do you know that you have a Mustangs unlimited housing to start with? Did you install them previously but then install stock bulbs? I find that hard to imagine since you said earlier that they included the bulbs?!?!??! Quote Share this post Link to post Share on other sites
miketyler 15 Report post Posted September 8, 2012 I have repop housings on mine as well. Need to look at them now to see if they are the same way. Quote Share this post Link to post Share on other sites
Mike65 476 Report post Posted September 9, 2012 This pic from the CJ Pony Parts catalog for a 65/66 Mustang clearly showing a 2 contact back up light assembley. None of the other assembleys can you see the contacts in the pic. Quote Share this post Link to post Share on other sites
danno 128 Report post Posted September 10, 2012 I think you have your answer, but maybe the one shown from CJ Pony was a dual contact, single filament bulb? I know they make some bulbs with one filament and both filament connections on the bottom. They do this when the mounting is electrically isolated from chassis ground. Boats often use these because of fiberglass (an no chassis ground). Maybe the one from CJ is this way so you can use a plastic rear valence? Quote Share this post Link to post Share on other sites
danno 128 Report post Posted September 10, 2012 I did some looking, and my previous message was right. These use 2 contacts on the base of the bulb, but a 1156 or 1157 will NOT work in these sockets. The 1142 will work, but you know that already. Quote Share this post Link to post Share on other sites
LoneWolf2U 136 Report post Posted September 10, 2012 The backup light bulb is 1142, Its a 2 contact based bulb with a single filiment. The Housing has 2 wires coming from it, One is the +lead from the backup light switch and the other is a ground. If the housings are installed correctly, There is a gasket/seal inbetween the housing and the valance, This will break the path to ground. Quote Share this post Link to post Share on other sites