4g61t.org :: Parking lights/ dash lights out, what to check?

Quote:

Went back out this morning and now the headlights don't work either and I found a 10a fuse under the hood blown. I replaced it and now every time I cut the headlights on it pops.

Sounds like you may have a short somewhere. If a cut or open wire is arcing itself to a ground that is close by, you could definitely blow fuses a lot. My Colt had a broken blinker wire that a mouse had chewed in half at the previous owners house. It took me over a week to track down the problem and find it. The broken wire ended up being in the fender well and very hard to find. Mine wasn't coming in contact with any ground, but moral of that story is.... Take your time and be patient, you will find it.

Get a good volt meter (not the AutoZone kind) and start checking voltage to and from the dimmer switch. Find where that terminates to and then follow the new route. This is easy to do if your wiring diagram has the correct colors and pin-outs on it. If you come to an area where all of the sudden you don't have power anymore, you will have to start probing the wire through the insulation with the lead to narrow down your search area. Back track until you find the problem.

Author:	89Mirageman [ Sun Mar 25, 2012 7:11 pm ]
Post subject:	Parking lights/ dash lights out, what to check?
This is on our 94 Summit wagon that we recently got running. I have double and triple checked that everything was plugged back in after installing the dash after the pedal swap. The warning lights on the cluster work but the back lights don't. Also the HVAC back lights are out along with the parking lights. A quick search on tuners said to check the dimmer switch but I bypassed this with no luck. Anybody else had this problem or know what to try for troubleshooting? I sent an email to the previous owner and he said they worked when he had it and I don't see why he would lie about it. Of course I checked all of the fuses under the dash and under the hood and none are bad.

Author:	Red Sleeper [ Sun Mar 25, 2012 8:23 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
ground wires? These things are sensitive about grounss

Author:	kaeser1 [ Sun Mar 25, 2012 9:01 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Do you have a wiring diagram for the car? I know on the 3g cars there is a junction block under the drivers side dash where a huge chunk of wires come into and exit back out of. The junction block consists of a few circuit boards to route all of the power and signals to where they have to go. For example: Click your left blinker, signal would go down to the power block and split to the dash cluster blinkers and to the correct blinker bulbs. If you can find the diagram, see if the dimmer power leaves the dimmer and goes to this block. Also check the appropriate pin locations on the plugs at the power block and make sure they are terminated. If you find the diagram, post a link and I can try to help eliminate some things.

Author:	89Mirageman [ Mon Mar 26, 2012 9:56 am ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Yeah I scored both factory shop manuals on ebay a few weeks ago for $17 shipped . I'll scan the lighting section and post it up. I messed around with it for an hour or so yesterday and really didn't get anywhere. Went back out this morning and now the headlights don't work either and I found a 10a fuse under the hood blown. I replaced it and now every time I cut the headlights on it pops. I also checked all of the grounds and they are grounded for sure.

Author:	Flying Eagle [ Mon Mar 26, 2012 1:12 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
I accidentally grounded one of the turn signal bulbs in the front bumper of the Colt and it was tripping fuses and creating headlamp issues IIRC. Light bulbs fiddled with?

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Parking lights/ dash lights out, what to check? http://4g61t.org/forum/viewtopic.php?f=22&t=36210	Page 1 of 2

Author:	kaeser1 [ Mon Mar 26, 2012 8:45 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Quote: Went back out this morning and now the headlights don't work either and I found a 10a fuse under the hood blown. I replaced it and now every time I cut the headlights on it pops. Sounds like you may have a short somewhere. If a cut or open wire is arcing itself to a ground that is close by, you could definitely blow fuses a lot. My Colt had a broken blinker wire that a mouse had chewed in half at the previous owners house. It took me over a week to track down the problem and find it. The broken wire ended up being in the fender well and very hard to find. Mine wasn't coming in contact with any ground, but moral of that story is.... Take your time and be patient, you will find it. Get a good volt meter (not the AutoZone kind) and start checking voltage to and from the dimmer switch. Find where that terminates to and then follow the new route. This is easy to do if your wiring diagram has the correct colors and pin-outs on it. If you come to an area where all of the sudden you don't have power anymore, you will have to start probing the wire through the insulation with the lead to narrow down your search area. Back track until you find the problem.

Author:	joemoto [ Fri Mar 30, 2012 1:16 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Quote: Quote: Went back out this morning and now the headlights don't work either and I found a 10a fuse under the hood blown. I replaced it and now every time I cut the headlights on it pops. Sounds like you may have a short somewhere. If a cut or open wire is arcing itself to a ground that is close by, you could definitely blow fuses a lot. My Colt had a broken blinker wire that a mouse had chewed in half at the previous owners house. It took me over a week to track down the problem and find it. The broken wire ended up being in the fender well and very hard to find. Mine wasn't coming in contact with any ground, but moral of that story is.... Take your time and be patient, you will find it. Get a good volt meter (not the AutoZone kind) and start checking voltage to and from the dimmer switch. Find where that terminates to and then follow the new route. This is easy to do if your wiring diagram has the correct colors and pin-outs on it. If you come to an area where all of the sudden you don't have power anymore, you will have to start probing the wire through the insulation with the lead to narrow down your search area. Back track until you find the problem. Looking for a voltage while dealing with an open will work, however when dealing with a short the fuse will blow and the only voltage will be on the battery side of the open fuse. I would find a proper circuit breaker, to save on fuses, and start removing parts of the the effected voltage's distribution. Ideally divide the circuit in half and move on. Two 5amp breakers in parallel will work for you, as long as their resistance is matched(forget about the matched resistance comment, it should not be a factor unless the breaker is bad).

Author:	89Mirageman [ Fri Mar 30, 2012 10:49 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Sorry for the delay, here are the scans of the lighting wiring diagrams. It's the 10a fuse marked with the # 3, it has a R/W and a G/W wire going to it and it comes from the headlight and taillight relays. How would I go about testing this to find the problem? Joemoto, I'm assuming I can get this 5a breaker from RadioShack instead of popping fuses during testing?

Author:	joemoto [ Sat Mar 31, 2012 7:48 am ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
I looked at my colt manual and was reminded that for a short it is easier to use a test light across the open fuse. while removing possible wire sections/loads/SHORTS to that voltage until the light goes out. The test light is much simpler to fab and use, , I am a electronic tech and do not normally spend my time in wire looms, thankfully. My set of manuals(89 colt) volume 2 Electrical page 8-23 the section called Wiring Harness - Troubleshooting show the method of isolating the short that I think should be used for your problem. PS. using a light will also give feedback about the amount of current in the circuit as the light gets brighter or dimmer. Basically using a test light and as access permits remove one section of wiring at a time until the section with the short is located/removed. The test light will go off or dim greatly.

Author:	89Mirageman [ Sat Mar 31, 2012 9:07 am ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Silly question but this procedure won't blow the light like it pops the fuse will it? So I can take something like an 1157 bulb and solder leads on it for testing? Thanks for your help!

Author:	joemoto [ Sat Mar 31, 2012 9:54 am ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Quote: Silly question but this procedure won't blow the light like it pops the fuse will it? So I can take something like an 1157 bulb and solder leads on it for testing? Thanks for your help! Not a silly question, it will not blow(should not ) In normal operation the filament within the lamp has 12volts across it. In re-reading your initial post about bypassing the dimmer and considering your PM question if that could be part of your problem I think YES. In theory the dimmer control while it was in the circuit was acting as a current limiting resistor which would prevent the fuse from blowing. Then when the resistor was removed the current increased and blew the fuse. If the short to ground is between the dimmer and the load/light then the above explanation would fit. Then go downstream so to speak and isolate/separate wiring and loads.(divide and conquer)

Author:	89Mirageman [ Sat Mar 31, 2012 8:51 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
As far as bypassing the dimmer I just unplugged it and used a paper clip to connect the two grounds together. I'm pretty sure that's how they said to do it on Tuners. This still didn't fix my problem with the dash lights so I just plugged it back in and assumed this wasn't the issue. After thinking about it, would the dimmer have to be plugged in to complete the circuit for other stuff or would it be ok to leave it unplugged? I know the correct way to bypass it would be to solder and heat shrink the wires but I wanted to see if this was the problem before going through all that trouble. I guess I could figure out how to test the dimmer in the FSM too.

Author:	89Mirageman [ Sun Apr 01, 2012 7:48 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Update, the fuse pops when I turn the headlights one click which is the parking/dash lights. The headlights are working again. The other day when I was probing the wires with my test light I opened up one of the terminals in the connector too big and it was not touching the pin when I plugged it back in. I closed it back up a little so now it makes the connection and the headlights work again. In other words the fuse popping had nothing to do with the headlights. Still need to troubleshoot some more and try to find out what's causing the fuse to pop and the parking lights and dash lights not to work.

Author:	joemoto [ Sun Apr 01, 2012 8:57 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
I see you made some progress, good. I have already sent you a PM.

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Author:	kaeser1 [ Mon Apr 02, 2012 5:33 pm ]
Post subject:	Re: Parking lights/ dash lights out, what to check?
Can you disconnect the plugs at each headlight and taillight and flip the column switch on and see if you still blow a fuse? If the fuse doesn't blow, switch it off, plug in on corner of the car, switch it back on and see what happens. If it doesn't blow, you have isolated that corner of the car. You can keep doing this until you isolate the problem down to one area of the car. It seems to me the issue is behind the dash rather than out at the lights. If the fuse pops and all you have on the circuit is the dash lights, then you know it is something inside the car. Have you been able to find the junction block I mentioned about? I see on your diagram that a bunch of connectors land there and then branch back out. Check to see if those connections are secure.