Finding a short

rrman61 · Aug 17, 2017

My sons 99 Tahoe's headlight switch is getting pretty hot to the touch.possible short?I don't
understand why it's not blowing the fuse.Can someone explain how to look for / find a short or any
other suggestions?

tim s · Aug 17, 2017

A loose connection at the plug,or a bad switch will heat things up,,some times the contacts in the switch wear to cause this..

rrman61 · Aug 17, 2017

Forgot to mention it is a new switch and possibly the problem is what killed the last one

Determined · Aug 17, 2017

Fancy aftermarket headlights can cause this.

Towing a trailer with too many lights and no relays will to.

Have gone through a few new switches that were weak out of the box.

If it has a short then nothing should be working, sounds like you are getting a high draw due to one of the above or poor connections.

Olliejunkie · Aug 17, 2017

(quoted from post at 08:58:04 08/17/17) Forgot to mention it is a new switch and possibly the problem is what killed the last one

How was the plug in end. May need to replace it too.

Bob · Aug 17, 2017

In addition to what the other poster said about replacing the connector, it is NORMAL for the area around the dimmer knob for the instrument lights to get damned hot, as it is simply a resistor and converts current to heat.

Eagle Beagle · Aug 17, 2017

Normal, nothing to worry about.

Beagle

pete 23 · Aug 17, 2017

If the knob is of the type you turn to dim dash lights, just turn them to full brightness and see if that cools the switch down. On full bright no current will be going through the resistor. If it still gets hot, poor loose connections , too small wire or connector or overloaded light circuit.

Geo-TH,In · Aug 17, 2017

An overheated terminal on old switch is something to look for. That could mean the part on the truck that plugs into the switch needs replaced. Look for heat stress, melted plastic. A bad connection will generate excessive heat.

If you had a short, it would blow fuses. That's what fuses are for.

jeffcat · Aug 17, 2017

Had this happen on my 1996 Explorer. Fried light switch. Several people have come close but this is what I did. Took the dash apart. The first big plastic pannel that trims and covers everything. This lets you run the vehicle for a couple of days with everything exposed so you can feel around. My light switch fried because the plug socket with all of the little connectors in it were crap. Went junk yarding and cut the harness out of another lower mile vehicle. Made lineman soldered connections with heat shrink tubing on them. Lot of work but it worked perfectly after that. The resistor is mentioned and some cars will get pretty hot as were others not so much. Depends. The brighter you run your dash lights, the cooler the resistor. You want a real shock, change them over to all LED. Lot of guys sell kits with every single LED bulb you will need for not that much on Ebay. Around 25 bucks or so. White or colors.

Finding a short

rrman61

Well-known Member

tim s

Well-known Member

rrman61

Well-known Member

Determined

Well-known Member

Olliejunkie

Well-known Member

Bob

Well-known Member

Eagle Beagle

Member

pete 23

Well-known Member

Geo-TH,In

Well-known Member

jeffcat

Well-known Member

Similar threads