Intermititent parking brake light

My parking brake light has started coming on intermittently. I disconnected the wire from the switch and it still will come on. So I'm thinking its a wire harness issue? Before I go through the entire harness. Has anyone else experienced this? If so, are their known trouble points in the harness I should troubleshoot first?

The biggest pia is the cruise control is disabled everytime the light comes on.

There's other reasons for that light to come on.
Like low vacuum, low brake fluid, pressure issue, etc. All of which can cutout cruise.
Also look up the cruise control recall.

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Thanks for your quick reply.

The vacuum and brake fluid is fine. What pressure are you referring to, the switch on the end of the master cylinder? I jumpered that and the problem remains. I have not heard of
the cruise control recall, what is that? The cruise only disengages when the parking brake light comes on or flickers.

Cruise control recall is because the switch on the master cylinder can go bad, cause fires. At least that is my understanding. My brake light was flashing/flickering, and it turns out I had a vacuum line pull off of my vacuum manifold. I thought my vacuum pump might be dying - so if I were you, I'd be conscious of the possibility of losing vacuum assist braking.

My breaking is working fine and has had zero issues. The vacuum pump is about a year old and I checked the connections.

79jasper mentioned the brake fluid level. My truck sat about 5 years before I purchased it and I had to work/loosen the fluid level float switch in the master cylinder before the light would stay off. I'm thinking it might be the culprit? I'm going to check it, maybe it's time to replace the 20 year old master cylinder?

Right, I'm not saying your braking is bad. I was just cautioning you in case you weren't aware. Now that you mention the switch being an issue before, yes, check that.

Update: I worked the float around on it's spindle and then took it for a 12 mile spin. No light. Is it fixed??? I'm not sure fit its sediment in the brake fluid reservoir, the float is less buoyant or something has happened with the spindle? I think it's best to just replace the master cylinder and have all the major brake components current.

Thanks for everyone's help.

MeTo said:

My truck sat about 5 years before I purchased it and I had to work/loosen the fluid level float switch in the master cylinder before the light would stay off. I'm thinking it might be the culprit? I'm going to check it, maybe it's time to replace the 20 year old master cylinder?

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Or at least do a brake fluid flush.

Billy T.
[email protected]

That was done when I bleed the system after installing new calipers/pads, drums/wheel cylinders/shoes and new tubes to the rear. If it was warm here in Wisconsin; I would replace the front tubes also. Probably when I fix my weeping oil pan?

The problem is solved. It was the float switch in the brake fluid reservoir. I ordered a replacement from Rock Auto.