Cruise Control not working after sequential tail light plug and play harnesses

[Thomaswalle]

Hello, I recently installed my sequential plug and play harnesses on my 04 Mustang GT manual transmission. I notice now my cruise control is not working. So after troubleshooting for a couple hours the only thing I can think of is that my cruise control module thinks my brakes are on all the time and that’s why it won’t activate? Does this sound right to anyone or has anyone experienced this??? I did put the modified raxiom flasher relay in as well…….

 

[cobrajeff96]

I'm pretty sure the only way a brake light activation works is through the brake pedal switch which is a positive connection. Unless the New Edge SN95s like yours are very different from the previous generation, that is. Easy test would be to just temporarily remove what you did and take it for a spin.

 

[GTamas]

I read earlier that the brake light bulb is connected to the cruise control circuit.
Check this thread:

Yes. The cruise control uses the filament resistance on taillight bulbs as a check measurement. Probably had incandescent third brake light bulbs before.

 

[07GtS197]

Did you switch to led bulbs? That’ll do it too.

 

[Thomaswalle]

I read earlier that the brake light bulb is connected to the cruise control circuit.
Check this thread:

Yes it did, but im still using the regular bulbs in the new plug and play harnesses. I didnt switch to led tail light bulbs.

 

[Thomaswalle]

I'm pretty sure the only way a brake light activation works is through the brake pedal switch which is a positive connection. Unless the New Edge SN95s like yours are very different from the previous generation, that is. Easy test would be to just temporarily remove what you did and take it for a spin.

Ok thank you! I may try that tonight just to see if that is the culprit. I just know LED bulbs use alot less resistance, so I am wondering if maybe my cruise control module thinks my brake lightare out, therefore wont activate due to that?

 

[Thomaswalle]

Did you switch to led bulbs? That’ll do it too.

No, I used the regular bulbs from the old harnesses. I did not switch to LED Bulbs.

 

[Thomaswalle]

I read earlier that the brake light bulb is connected to the cruise control circuit.
Check this thread:

Thank you for the reply. Thats what i was thinking so that makes me feel more optimistic that maybe i just need to install a diode t-tap kit.

 

[Thomaswalle]

Did you switch to led bulbs? That’ll do it too.

No I did not. I used the stock bulbs and just did plug and play sequential harnesses and changed the flasher relay to the raxiom modified flasher to slow the speed of the turn signals down.