I bought an aftermarket head unit and a friend was putting it in for me. I didn’t buy the aftermarket harness and was planning on just splicing the wires into the head unit harness, which I’ve done before on my 97 camaro.

The wires are very confusing and there is an extra wire from the car (green with white stripe) that I can’t figure out where it goes to. The head unit won’t work at all which is frustrating, but now my dash (tach, Speedo and mileage/trip) all seemed to not work. I connected 2 wires from the car together and now they all work (head unit still does not) but now the tripometer resets every time I start the car.

Does anyone have any suggestions on the fix? Also maybe if I can find an oem monsoon harness, I can resplice the original wires, buy the the harness adapter and just plug to the head unit. Thoughts?

 

‘Welcome to LS1Tech! We have a section of the forum titled Stereo And Electronics. Re-post this over there and you’ll get plenty of help. Not much traffic here in the intro section.

 

This is the very reason we always recommend spending the $10 for a wiring harness adapter - to avoid incorrect connections which can cause other electrical problems. It also makes the head unit plug-and-play so it can be removed for service work or when you want to upgrade in the future. Fortunately, Metra (the maker of the most popular harness adapters) anticipated this situation... they also make replacements for the butchered car end of the harness. Part number 71-1858 is the adapter which will replace the factory harness plug you removed. Then part number 70-1858 is the harness adapter which will connect to your aftermarket head unit and plug into the replaced factory harness plug.

There are two dark green/white wires in a Camaro stereo harness - the one in the small connector is for the right audio signal from the optional external CD changer and the one in the main white connector is for the speed signal that controls the speed-sensitive volume feature of the Camaro radio. Depending on what you've connected that wire to, it could be the source of your trip meter problem. It could also have caused a more serious problem with that circuit... disconnect it and hope it starts working again (it's not needed for any aftermarket head unit although a few with GPS navigation may use it optionally to estimate position when GPS signal is lost).

The wires in the factory harness are separate for a reason and they should never be connected together. You may have gotten lucky with splicing two together by possibly connecting an alternate power source wire to get things working but you could have just as easily done serious damage. I suspect that you blew a fuse and then by connecting two power wires together (e.g. battery and ignition) bypassed the blown fuse. You should immediately separate those two wires for safety.

There is a wealth of information about the Monsoon system and its wiring in the Monsoon FAQ sticky at the top of the forum.