• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Wiring Issue - I think i have a short!

L

lethal289

Active Member
So i bought my car in may of 08 as somewhat of a basket case. At that point it had not ran in 13 years. When i got it running i noticed that i didnt have dash lights. I had turn signals, hazards, the brake light, and the high beam indicator on the cluster would work. First thing i think is a fuse, so i check the 2.5 amp aga instrument cluster fuse and its blown.

I thought no problem, ill order a couple and ill change it up. Well as luck would have it, i never looked at the fuse again until yesterday.

Last night, After wiring my Autometer Phantom gauges, with the original instrument harness, i again noticed no dash lights. Odd, since i bench tested the cluster, and everything worked and would light up. Remembering about the fuse, i put one in and tried again. Turned on the headlights to light the gauges and there was no light to be found. With in seconds i saw a trail of smoke comming from the center of the dash. Obviously i have a short some where, but is there anything common with these cars that could cause an issue? Or something standard to look at first? I tried looking for whatever was smoking, and couldn't find anything yet. The fuse i put in is again blown, and i dont want to try again, unless i cant find anything else. Anyone have any ideas?
 
This is kinda funny, all day I've been watching the new posts and this is the VERY FIRST Mustang related post of the day (other than the MITM post, but thats more about the CA :gobp )...... I dont have an answer for ya though, I got a bunch of other threads to catch up on....
 
Thanks rick, question for you though. I look through your build thread, and notice your gauge cluster, you dont have the wiper switch. did you not wire it, or did you just set the cluster in there for the pic?
 
on second thought maybe it is there...

2_08_09_08_9_32_16_0.JPG
:conf Im not sure
 
Dash lights are rather simple, and hard to blow fuses with. Look for blue/red wires: there should be two on each side of the dash cluster for 64.5-66. For 67/68, they go through the intermediate harness, where there's a splice that goes to the individual lights. The light sockets themselves should have the plastic insert surrounding the little bulb tit in the middle; the housing itself is the ground.

Also on this circuit are some miscellaneous lights, such as for the console and radio. Power comes from the headlamp switch through the fuse box to the dash harness and radio (for 1967), and sometimes a three-prong plug for additional dash lamp applicatons. Here's what I would do for trouble-shooting: disconnect the underdash to dash harness and use a new fuse. Turn on headlamps and see if the fuse blows. If it does, it's likely the radio or additional accessories. If it doesn't, focus your attention on the dash cluster harness and the individual light sockets.
 
The smoke from under the center area of the dash indicates to me that you have a dead short somewhere in that area.

Look for a wire that is pinched between two brackets or smashed under something that is bolted in. Obviously you should also look for wires touching any metal and check for worn/missing insulation from the wires at those points.
 
Thanks Guys, i wont get a chance to get into it again until thursday.

Mid - Ill be sure to do that. Thats a good way to eliminate the cluster from the mix. Although im pretty sure its not the issue. Thanks.

Sluggo - I looked for about a half hour and did not find anything. Ill be sure to dig a little deeper. Thanks.
 
you can make a short circuit finder with a resettable circuit breaker and a compass:

http://books.google.com/books?id=3q85p56_PxIC&pg=PA47&lpg=PA47&dq=how+to+find+a+short+circuit+with+a+compass&source=bl&ots=neLzZ5QVYG&sig=4yW2RVR5ONsoDRfCL1C9sgGJiCA&hl=en&ei=rY2eStGfH5SJ8QbkptSnAw&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q=how%20to%20find%20a%20short%20circuit%20with%20a%20compass&f=false

The circuit breaker should keep you from having a melt-down, the compass will help you find the location of the short.

HTH,

Steve
 
You must log in or register to reply here.
Back
Top