Thanks ls1nova71 for the help on cruise

[Custom 68]

I wanted to give some kudos to Eric for the wonderful insight on adding cruise to my swap. http://67-72chevytrucks.com/vboard/s...d.php?t=511477
This thread says it all. It is an easy swap with this set of instructions. Also thanks to all the others that added to this along. I would highly recommend this. It can be done on the cheap with pick n pull parts.
Again thanks and this is a great site with everyone willing to offer their findings.
Dave

[oldman3]

Just wanted to add that Eric is a top-notch guy, willing to help anyone with LS info. I met him in 2017 at Mid-America nats...Jim

[ls1nova71]

Aw geez guys, you're going to make me blush! LOL! I enjoy helping others with what I enjoy doing, and hope its good for at least a little good karma!

[Clyde65]

He has been that way for a long time! He helped me with my cruise control ( among other LS stuff) about 7/8 years go! Good man and very helpful!

[Daaaanz67]

Got my cruise lever from him years ago and still working. Top notch lever. Thanks again Eric.

[NC_John]

Here's a CC question. Mines not working - DBW, blue/green PCM, speartech harness, rostra cruise control stalk with relays installed as illustrated in other threads to give the newer PCM the signal it wants.

With the tech 2 I am borrowing for the weekend, I have been able to check all my control switch functions and signals to the PCM.

Cruise Control Active - No. (I assume because truck has not hit min speed required). I need to road test for this input later.

Cruise On/Off Switch - yes, input changes as I work switch on stalk

Cruise Set/Coast Switch - yes, input changes as I work switch on stalk

Cruise Resume/Accel Switch - yes, input changes as I work switch on stalk

Stoplamp Pedal Switch - (assume this to be brake pedal). yes, input changes as I depress/release brake pedal

Here is the one I don't understand-

Cruise Release Brake Pedal Switch. This does not change... but as I type this now I wonder if it won't work until the truck is at speed, cruise is enabled and functioning and THEN the brake pedal is depressed to turn off the cruise.

Anybody know for sure? I'm also not sure where it is looking for the pair of wires Speartech provided for a clutch switch. Changing that input didn't have an effect on anything the tech 2 showed.

It looks like I am real close to having my cruise control work but there is still a missing piece.

[ls1nova71]

Do you have both brake switch inputs hooked up? Should be one from the PCM that needs power with the brakes not applied and one from the TAC module that. Reds power with the brakes applied. Also, do you have LED taillights by chance?

[NC_John]

Originally Posted by ls1nova71

Do you have both brake switch inputs hooked up? Should be one from the PCM that needs power with the brakes not applied and one from the TAC module that. Reds power with the brakes applied. Also, do you have LED taillights by chance?

I've been thinking about this and crawling under the dash to look at stuff all day. I have the light blue to the brake light switch but I wonder if I have it tied to the wire on the wrong side of the switch which is why it shows no status change when I hit the pedal. I'll have to either see what I can see in the factory wiring diagram (or just switch to the other wire).

No LED tailights. Probably that light blue wire....

thanks... I might be on the right track to fix this now. I tell you what- this Tech 2 has been a HUGE help in troubleshooting. I might have to buy one of the knockoffs.

[NC_John]

I switched the blue wire from the white brake switch wire to the orange (couldn't figure out which side I needed from the service manual schematics). No change in input status but I've also lost the input change on the other brake switch that WAS working. I think I am going to stop until I get a new pcm in there. I am just chasing my tail right now with too many issues going on at once.

[BR3W CITY]

This is interesting, because I've been looking at doing the absolute most minimal cruise setup possible. Don't need a stalk, just want a single "cruise" switch with the brake safety.

[ls1nova71]

Originally Posted by BR3W CITY

This is interesting, because I've been looking at doing the absolute most minimal cruise setup possible. Don't need a stalk, just want a single "cruise" switch with the brake safety.

Super easy. Just make sure the brake switch is wired up and hook a momentary switch on the SET wire on the TAC to 12v.

[truckdude239]

i have yet to hook mine up on my 2004 4.8 dbw ive read alot about having to use relays i just wanna find something i can hook right to the wires of the tac module

[ls1nova71]

Originally Posted by truckdude239

i have yet to hook mine up on my 2004 4.8 dbw ive read alot about having to use relays i just wanna find something i can hook right to the wires of the tac module

The relays are for aftermarket column mounted cruise switches. The only ones that work without them are factory GM switches and the dash mounted ones from DD and Rostra.

[truckdude239]

So if i got tbe one like on the old blazer where its on the turn signal stock it should wire rigbt in

[ls1nova71]

Originally Posted by truckdude239

So if i got tbe one like on the old blazer where its on the turn signal stock it should wire rigbt in

Not sure what the old blazer you are referring to is, but if it's a 4 wire GM switch it will work.

[Advanced Design]

Adding my thanks too. Though I bought the 72 Burb done, it has tap up, tap down cruise that works great. In the materials the p.o. provided was a printed copy of the cruise thread you created. Thanks again!

[truckdude239]

https://www.summitracing.com/parts/rpc-250-3020

Was what i was looking at but its a rosta and i read will only work aftermarket and not oem with out relay any idea on a gm switch that works

[ls1nova71]

Originally Posted by truckdude239

https://www.summitracing.com/parts/rpc-250-3020

Was what i was looking at but its a rosta and i read will only work aftermarket and not oem with out relay any idea on a gm switch that works

The only factory switch that will bolt to an old column, the single screw type, is one from an 83 Chevy truck. 81-83 or maybe 84 will work but some are 3 wire switches and need the switch chabged.

[truckdude239]

Originally Posted by ls1nova71

The only factory switch that will bolt to an old column, the single screw type, is one from an 83 Chevy truck. 81-83 or maybe 84 will work but some are 3 wire switches and need the switch chabged.

Okay will see what i can find

[Big Moose]

Here's another Cruise Control question:


6.0L / 4L80e out of a 2005 2500HD swapped into a 1985 C3500
DBW Throttle using a harness from Painless Performance

Cruise was working for the better part of 2 years and then it quit.
Checked the brake switch and confirmed it's working.
Checked the Cruise On/Set switch on the signal lever and confirmed it's working. I checked these at the TAC plug to make sure the harness wasn't at fault So I decide it must be the TAC, tried 2 different TAC modules and still nothing.
I was wondering could the pedal or the throttle body be at fault and how would I be able to test them

[ls1nova71]

Generally when the cruise stops working on those trucks, its due to the wires breaking inside the column that go to the switch, but if you've checked them, that must not be the case. Have you changed anything that could have caused it? LED brake lights for example. So you checked for power at the TAC for the set/coast and on/off and they have power? Also, its possible that the brake switch is out of adjustment since they went to the push in type of brake switch rather than the actual bolted in one, so you might try pushing it back up a bit and see if that helps.