In Line Fuse Blows on Driving Lights wiring

I installed a set of Blazer Tech driving lights sometime ago and have had good luck. A few weeks ago the Blazers didn't turn on and I found out the white power "turn on" had chaffed and the exposed wiring was grounding on a metal contact. I taped the wire up and problem solved. Now, within the last day the in problem has reoccured. As soon as the Fog light switch is activated the fuse blows. I examined the white power turn on wire and it appears fine. Does anyone have any suggestions? I disregarded the instructions and used the BlazerTech Grand Prix ones that have been floating around here. Any help would be appreciated.

Sounds like you still have a short. What is the current rating of the relay that you are using for the Blazer Techs. If you used the existing stock wiring without any mods then maybe the fog light relay took a hit.

Thanks for the reply. I am not sure I know what your asking about the relay. The relay takes a 15a. I do have a multimeter to check it and I also do have another complete wiring harness. If the relay is bad could i just use the other harness? It too uses a 15a? Thanks in advance.

Thanks for the reply. I am not sure I know what your asking about the relay. The relay takes a 15a. I do have a multimeter to check it and I also do have another complete wiring harness. If the relay is bad could i just use the other harness? It too uses a 15a? Thanks in advance.

When you press the fog light switch it energizes the fog light relay which is typically 15 amps. I believe the relay either the coils or contacts are after the fuse protection so the relay going bad is a possibility or maybe there is more damaged wiring. You can change out the relay if it matches spec. wise or use the other harness. It takes a lot of current draw to pop a 15 amp fuse indicating there is a short circuit somewheres.

Thanks for your responses...much appreciated. I swapped out harnesses today and put it a new one / the fuse still blowed once I turned on the fog light switch. Guess I am a little confused at this point.

Thanks for your responses...much appreciated. I swapped out harnesses today and put it a new one / the fuse still blowed once I turned on the fog light switch. Guess I am a little confused at this point.

Disconnect the electrical connectors going to the driving/fog lights (both of them). Make sure fuse is good and then press fog light switch. Let me know what it does.

BTW - Is this the Blazer Tech procedure you were referring to?

http://www.grandamgt.com/angeleyeinstall-pfyc.html

The link I used for instruction on the 3200 install was
http://grandprix.net/upgrades/blazerindex.html

Tonight, I went to work on the lights. As noted earlier I swapped out wire harnesses.
-Scuffed up Relay metal contacts
-Inspected red in-line fuse connection with fuse junction box
-Inspected one light housing to confirm that the internal wiring was grounded and connected.
-Unconnected the electrical connectors and reconnected them as you mentioned.
-Checked fuses in fuse junction box
I think I should mention that I also swapped out hub/wheel bearings last week. I am not sure how that could be related but I thought I’d mention it. I also wire loomed the white “turn on” wire with the red and black fog light wires. The red and black wires are insulated themselves but I grouped them all together for aesthetic reasons. I was also thinking of taking the red in-line fuse wire and connecting it to the positive battery instead of the junction box.
Thanks for your help with this. I appreciate it very much. Those factory headlights are so horrible that I am dependant on the 3200’s.

I also failed to mention that each time I turned on the fog light switch the fuse blew. You could hear an audible click coming from the engine each time the fog light switch was pressed, even after the fuse blew (maybe thats normal). Also, the fog light switch itself is glowing.

I also failed to mention that each time I turned on the fog light switch the fuse blew. You could hear an audible click coming from the engine each time the fog light switch was pressed, even after the fuse blew (maybe thats normal). Also, the fog light switch itself is glowing.

Thanks for the right link. I reviewed the wiring diagram. Instead of using the stock fog light relay in the engine compartment fuse box it has an indpendent 15 amp relay which makes sense for safety reasons. However, to energize the relay when the fog light button is pressed it is simply using 12v via the original wiring at either one of the original fog light wiring harnesses. So the stock fog light relay is still being used in the engine compartment fuse box. When you press your fog light button all it is doing is energizing the stock fog light relay which in turn energizes the relay in the wiring diagram by providing 12 volts. To pop that inline 15 amp fuse you still have high current draw or a dead short. You mentioned replacing the harness earlier but have you replaced the relay?

Now if the relay is good and all wiring specifically the white wire shown in the wiring diagram then there is a high probability the stock 15 amp fog light relay in the engine compartment fuse box may have gone South or that specific leg of wiring has a short, ie: from the output of the stock fog light relay to the point where you tapped into the stock wiring harness. You can pull the stock relay and inspect the contacts and the socket and look for any signs of arcing or fried contacts. I'm quite sure the stock fog light relay is the clicking sound you hear so that is normal.

If you need the factory wiring diagram for the fog light system to see what I see I can provide the one page. Good luck!

BTW - Do you have access to a multimeter and know how to use one?

Thanks again for the helpful information. You'll have to bare with me due to my lack of knowledge but from what I read, you say that I should check out the stock fog light relay? You also advice that I check out the bigger 15a fuse for fog lights that are in the junction box? I will check on those asap. I don't know where the stock fog light relay is. Inside the junction there is a fog light fuse that is small and a fog light fuse that is large in size.....is that not a fuse but a relay?

thanks again

I do have access to a multimeter and am so-so with using it.

I do have access to a multimeter and am so-so with using it.

Great because we may need it. But for now I'd definitely checkout the stock fog light fuse and relay. Both are 15 amp rated. When you remove the cover for the engine compartment fuse box by the battery it will have a placard on the lid. Just follow it and it will show you the fuse and relay location. The relay is a plug-in type that goes into a socket. So you can just unplug it.

I checked the fuse and relay. As a matter of fact I bought a new relay and put it in. I switched the other 15a fuse with another. I unplugged both the electrical connectors going to the lamps and then flipped the fog light switch and the fuse blew. I may need some advice on using the multi-meter on the stock "turn on" purple wire, but before I do that should I remove both lamps and make sure the inernal wiring is grounded? One of the internal wiring on one lamp unplugged itself while I was originally installing it. So maybe I am thinking that it came off again. Would that cause a short?

thanks again, I really appreciate the help.

andy

I checked the fuse and relay. As a matter of fact I bought a new relay and put it in. I switched the other 15a fuse with another. I unplugged both the electrical connectors going to the lamps and then flipped the fog light switch and the fuse blew. I may need some advice on using the multi-meter on the stock "turn on" purple wire, but before I do that should I remove both lamps and make sure the inernal wiring is grounded? One of the internal wiring on one lamp unplugged itself while I was originally installing it. So maybe I am thinking that it came off again. Would that cause a short?

thanks again, I really appreciate the help.

andy

If you disconnect both connectors to the fog lights and the fuse still blows then you can rule the lights and internal wiring out. On the wiring diagram where the white wire is and where you tapped into I believe a purple wire you'll need to undo that point. Then pull the stock fog light relay in the engine compartment fuse box. Take a multimeter in the resistance/ohms position. Take red lead to the purple wire and black to a good ground such as battery negative. If meter reads anything such as 0 then there is a short in the wiring run. If it doesn't do anything then the wiring is probably OK.

I'm wondering if the problem is the on the other side of the stock fog light relay going back to the fog light switch?

Well with soem uidance from you I was able to find the problem and fix it. I unhooked one of the fog lights connector at a time and was able to isolate the short. One of the internal wirings on the fog light became disconnected and was causing the short. I should have gone through the easier and more obvious problems before pulling out the harness and replaing the relay! Thanks gain for the help,...the electical work is something that completely mystifies me.