wiring problem insturment cluster lights and taillights

[slimcat7m3]

Sorry I posted this topic in the wrong spot previouslyI am having a wiring issue with my 89 240. I recently installed a boost controller in my car and initially installed it wrong. I am a capable mechanic just wired it wrong. Now that is fixed but around the same time my battery/alternator light came on. I checked the charging voltage and it was low so I had it rebuilt. When I installed it the alternator seems to be charging but the light never went out. I am sure my other problem is related so when I turn my headlights on I blow the taillight fuse and my instrument cluster lights and taillights don't work, headlights and idiot lights still work. I have my whole dash and left side of the car torn apart, and cannot find any thing. Its probably a ground wire somewhere but could some one give me an idea of where to look. I have been looking for days. Keep in mind I had no issues before I installed the boost controller. Any help would be great. Thanks

[NISTECH]

post a comprehendable wiring diagram of this boost controller and a wiring diagram of the car , indicate the wires you tapped into initially incorrectly and where you have them tapped into now on your cars wiring diag.

[slimcat7m3]

My car is running fine now, but i still have the same alternator light on. I will get a diagram drawn up of the wiring, by the way it was an apexi avc-r boost controller. I will check the voltage from the alternator with an volt-meter to make sure it is charging properly. If it was I would assume the light would go out on the dash. Could an alternator cause a problem such as this. The alternator rebuilder is very reputable. Could a relay have gone bad in my light wiring? The instant I turn my headlights on the taillight fuse blows so there are no panel lights or taillights. As mentioned before my headlights and brakelights work just no taillights. Besides the alternator light being on my car is running fine. Thanks for the help

[NISTECH]

On your taillights I am more thinking you have a bad tail light bulb. If it were me I would remove the front parking light bulbs and tail light bulbs [same circuit] put a new fuse in and turn on the lights. If the fuse doesnt blow start reinstalling the bulbs till the fuse blows. When it does you found the one causing the short. I actually dont use fuses for this, I have a circuit breaker with a buzzer to tell me when the circuit shorts.But for you it would be cheaper to burn a few fuses then to go out and buy this $75 kit.

The altenator light is due to a bad ground in it or on it. If it has an external ground make sure its hooked up.

[slimcat7m3]

I pulled all of the lights and the fuse still blew. Could my whole problem be related to my alternator?. I checked the external ground and it has good continuity. Should I pull the alternator off and have it checked. Thanks for the help

[NISTECH]

An altenator problem will no blow your lighting circuit. Since your fuse is still blowing with all bulbs removed ,I hate to say it but it looks like you may be dealing with an instrument panel short. i.e there is a short somewhere behind the dash. At this point knowing exactly what you tapped into by accident when you installed the controller is important.

[slimcat7m3]

I pulled my alternator and sent it back to the rebuild shop. I beleive that the problem would be with the voltage regulator. Could my headlight switch be the cause of my light problems, it seems to be one of the only things the lights have in common? Thanks for the help

[slimcat7m3]

The rebuilder put a new voltage regulator in the alternator and said it tested fine. I installed it on my car and the same issue persists. It charges fine once I rev the engine once. I am going to try a new headlight switch on saturday.

[slimcat7m3]

The wiring roblem is around the ecu because now my car is having problems revving past 5000 rpm. I will check where I tapped into the wires incorrectly. Sould this be maf related?