Gen 3 Drive By Wire cruise control HOW TO

[reaper71]

Sorry as far as I know.

Brendan did my engine Harness for me, cut and slimmed down from the factory unit. One thing I find odd...I have the 4 wires for cruise coming from the engine harness connected to them but There is nothing technically going to the tac module (meaning the wires stop short of going to it) I was told to connect to these 4 wires on the engine harness side.
Shouldn't it be also connected to the module then?
If not how the heck does it get it's signal in the first place??

Mark

[ls1nova71]

The wires do go to the TAC. If you want to give me a shout I can walk you through the diagnostics. PM sent with number.

[reaper71]

Will Do,Thank's Eric

[reaper71]

As of this morning I do have all signals sending to the TAC module at this time I'm Having Brendan from Lt1 swap coming over this afternoon to hook up to the truck to do a scan and see if something else is not working properly.
Will update later

Mark

[reaper71]

Ok Guy's I'm back with (hopefully my last) Update!

Brendan came out to the shop today and hooked up his GM scantool and all of the functions of the cruise,brakes etc are all working!
We then hopped in the truck and went down the road and Boom I Have Cruise!!
It is the weirdest thing I did not touch a single thing from Saturday
At least it work's..
A Big Thank's to Eric (LsNova71) and everyone else who offered advice!

Mark

[sshamu]

Originally Posted by reaper71

Ok Guy's I'm back with (hopefully my last) Update!

Brendan came out to the shop today and hooked up his GM scantool and all of the functions of the cruise,brakes etc are all working!
We then hopped in the truck and went down the road and Boom I Have Cruise!!
It is the weirdest thing I did not touch a single thing from Saturday
At least it work's..
A Big Thank's to Eric (LsNova71) and everyone else who offered advice!

Mark

So is the wiring diagram listed in post #42 the correct for your solution?

[reaper71]

SSHAMU Sorry man I didn't post the updated diagram!
When I get to the shop this morning I will take a shot of it and get it posted.basically the wires are all wired direct from the switch and with the new LED resistors installed it works great (NO Relays)

Mark

[sshamu]

Thank you sir. I'm ready to wire mine up (including the LED taillights with HND-2 switch) and test it out this Saturday.

[GM man]

Originally Posted by reaper71

SSHAMU Sorry man I didn't post the updated diagram!
When I get to the shop this morning I will take a shot of it and get it posted.basically the wires are all wired direct from the switch and with the new LED resistors installed it works great (NO Relays)

Mark

Did you ever post the diagram of what you wound up with?

[reaper71]

This is the wiring I ended up with. Hope this helps.
And the resistors were used for the tail lights (LED Only) With this setup You do NOT need any relays.

Mark

[ls1nova71]

Originally Posted by reaper71

This is the wiring I ended up with. Hope this helps.
And the resistors were used for the tail lights (LED Only) With this setup You do NOT need any relays.

Mark

Just to clear things up a bit, you are referring to not needing relays to run the LED tail lights. You are also running a dash mounted cruise switch, the only aftermarket switch that has the same style internal switches as a factory GM switch. At the start of this thread however, the relays used are for using an aftermarket column mounted cruise switch, which will need the relays. Hope this clears things up for anyone in the future that sees this thread.

[reaper71]

Yes thank's Eric for that forgot to mention it!!!

Mark

[GMC Guy]

This thread answered all my questions finally.
The other day I hooked up the column mounted switch, Rostra part #250-3020 less than $50. Same as the one OP used.
Works great, minus the Resume/Accel feature. The Set/Coast and Resume/accel are tied together in the switch itself?
I'll go back and wire in the relays as outlined and hopefully that'll do the trick.
Has anyone figured out how to connect a light to turn on when cruise is engaged? and for tow-haul mode for that matter. I don't have Dakota digital gauges yet, but I know they have that feature built in.

[GMC Guy]

I followed the relay diagram exactly and the Resume/Accel feature still doesn't work..
anyone figure out how to make it work without adding a separate momentary switch?

[Big Moose]

Have you tested the resume/accel switch to see if it works?

[GMC Guy]

Originally Posted by Big Moose

Have you tested the resume/accel switch to see if it works?

tested everything again and found a bad connection on the yellow wire. Seems to function correctly on the multi-meter now

[Big Moose]

Been there and had fun with that, the aftermarket switches work sometimes and sometimes not.

[GMC Guy]

Well I discovered one small glitch in the cruise control matrix. With the lights on, and cruise engaged, as soon as I use the turn signal, cruise disengages. Just as it would if i touched the brake pedal. What's strange is, only happens with the running lights on. Lights off, and I can change lanes with my turn signal and cruise all day. Do I need a diode above where I tapped the brake light switch?

[bigoilman]

Originally Posted by GMC Guy

Well I discovered one small glitch in the cruise control matrix. With the lights on, and cruise engaged, as soon as I use the turn signal, cruise disengages. Just as it would if i touched the brake pedal. What's strange is, only happens with the running lights on. Lights off, and I can change lanes with my turn signal and cruise all day. Do I need a diode above where I tapped the brake light switch?

Did you ever get this resolved?

[GMC Guy]

Originally Posted by bigoilman

Did you ever get this resolved?

I did, by putting standard bulbs in place for brake lights/front turn signals. It's obviously a resistance issue with the LEDs.. I've found that with these old style wiring harnesses where nothing is relay controlled, LEDs just create a lot of headache, in certain areas. Places where they don't need to flash, they do great, ie. dome and courtesy lights, back up lights, dash, license plate, etc.

One day when i have loads of time (lol) I'd like to experiment with adapting a gmt-800 (03-06) full body wiring harness into a square, full BCM and canbus functional. I just think the idea of modern conveniences with classic styling would be the coolest thing.

[reaper71]

If your running LED lights just use these resistors in line. I had the same issue and this will fix the problem.
You can either run them in the back with your tail lights,or just under dash at the brake switch (you only need 1)


https://www.amazon.com/Zento-Deals-Pieces-Load-Resistors/dp/B01N0ZKV1R/ref=asc_df_B01N0ZKV1R/?tag=hyprod-20&linkCode=df0&hvadid=312190333361&hvpos=1o3&hvnetw=g&hvrand=17934858619714200296&hvpone=&hvptwo=&h vqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9023792&hvtargid=aud-801381245258:pla-568827705785&psc=1

[reaper71]

Sorry they look like this.

[GMC Guy]

Originally Posted by reaper71

If your running LED lights just use these resistors in line. I had the same issue and this will fix the problem.
You can either run them in the back with your tail lights,or just under dash at the brake switch (you only need 1)


https://www.amazon.com/Zento-Deals-Pieces-Load-Resistors/dp/B01N0ZKV1R/ref=asc_df_B01N0ZKV1R/?tag=hyprod-20&linkCode=df0&hvadid=312190333361&hvpos=1o3&hvnetw=g&hvrand=17934858619714200296&hvpone=&hvptwo=&h vqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9023792&hvtargid=aud-801381245258:pla-568827705785&psc=1

Those are exactly what I tried, and for the most part worked. except I still had the issue above, as well as my turn signal indicators would stay dimly lit to indicate there was low resistance on the circuit. I had tried the resistors on each bulb as well with no success.

[Thealien]

Tagging for later

[cpnbnanamn]

Originally Posted by ls1nova71

Just to clear things up a bit, you are referring to not needing relays to run the LED tail lights. You are also running a dash mounted cruise switch, the only aftermarket switch that has the same style internal switches as a factory GM switch. At the start of this thread however, the relays used are for using an aftermarket column mounted cruise switch, which will need the relays. Hope this clears things up for anyone in the future that sees this thread.

Sorry to resurrect such an old thread, but I'm stuck and frustrated. I'm trying to wrap up an LS swap into my '78 K5,(yeah yeah, I know. I have a post over there, too) using an LQ3 from an '05 Yukon Denali. So far, evreything is going pretty well.. (ask me about the 4L65E to NP203 mod... after I've been drinking heavily) and I'm trying to finish up the cruise control lever. It had a single-button lever that was supposed to actuate a cruise servo. That's all gone. SO: I have the TC pinout, bought a replacement lever from Ididit (looks like a Rostra), and fished it down the column. Here's my issue: If what I'm reading is correct, the column -mounted lever will not work with the TCM because the switches at NO? And am I also reading correctly that you have to use relays to correct that? Gaah.

Is there another GM lever that can be used instead? It appears that the ones that are compatible with the TCM have the issue of mounting in the column - slotted pin instead of a tab with a screw into the canceling cam. Or am I stuck with the one I bought and relays?
Also, if all it's doing is changing out NO to NC, I'd think a light-duty relay might accomplish this. Not a lot of amperage is going to the TCM for signaling. Am I incorrect? Any constructive input is gratefully appreciated.

I'll get back the the '67 when this truck is done and sold.