Hey guys, I’m in a bit of a pickle. I’m currently 2 hours away from home at the hospital with my wife while the T4R is in the shop. Truck randomly starting clunking while trying to start. We tested battery and alternator and both are good. However, it will not crank unless you have an outside power source hooked to the battery (and even then not every try works). Once it cranks, it stays cranked with no issues (no battery light and no electrical problems).

This is where I need help. When I bought the T4R years ago from a guy on the forum, he had some type of MOD done to it near the air box. I can’t remember what he said it was for, but it had something to do with tricking the computer and not throwing a code. However, one of the wires are going down to the starter. The shop said as soon as they removed this wire, it started up and it’s not having any problems. Trying to figure out exactly what this MOD is and why it’s causinf issues now after all these years.

If its an 05'+ V8 it could be an air injection bypass kit. But it shouldn't be wired to the starter. To the fuse box and I think the MAF sensor cable near the air intake box.

Secondary Air Injection Pump Failure on V8's! Important!

Secondary Air Injection Pump Failure on V8's! Important!

Mine is 05 v8 sport. That may be it. Thanks.