I recently purchased a 2001 4x4 Blazer (W Vin) and had to replace the wire harness due to a check valve gone bad which burned a large section. While removing the old one I disconnected two wires, Purple w/ White Line and Gray, which did not appear to routed OEM to the harness. These two wires come through the firewall under what I assume is the cruise control box.

I checked the side of the wire harness going to the Fuse Relay Center box and identified a Purple wire w/ White Line going to one of these three fuses IGN B (50A), RAP (50A), IGN A (40A) . Currently the truck starts but has an incredibly weak idle and dies within about 60 seconds and I also cannot put the truck in gear.

I am hoping someone can help me with the correct way to route and connect this wire. The wire itself appears to be OEM based on color and condition.

The HOA is on my *** so thanks in advance,

 

I thought purple and white was for the VSS, but I could be wrong.

 

I followed the wire on my old harness and this is what I found.


fuse box - my thumb is on the location of the wire in question

fuse box - wire in question

ecu - wire is in terminal labeled 21

 

wire connecting to O2 sensor

wire that was cut which is tapped into connector for the alternator i believe

wire that was cut which is tapped into connector for the alternator i believe

 

Do you know if its supposed to go through the firewall?

 

Apparently, there are multiple purple and white wires. I posted this diagram for somebody else yesterday. Maybe it will help you out, too.

 

Do you know if its supposed to be routed through the firewall?

 

Thanks incredibly helpful, thank you. After glancing at it it appears that is could be VSS or O2 sesor. Not sure if either of those are intended to go through the firewall. I could see O2 sensor being attritubted to my terrible idle but a vacuum leak could also be the culprit there

 

I can't say for sure, but I wouldn't expect it to be.

 

Im curous if its possible that this goes to the hood switch to control the light