Cruise control on 86 Q's..... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

locab36 · 01-16-2006, 10:21 PM

I'm working on a 86 SWB right now and as it waits for better weather for a 350c.i. transplant I have a couple questions. I will not be using the factory wiring/spark control(wiring cut by some PO). Just a plain HEI ignition. I want to retain the factory cruise control. It has the Vac dashpot w/the long rod to carb. Looks to have a vac line to the brake light switch for deactivation. Truck has the 700r4 tranny and I plan on a BTO conversion for my holley and tcc lock up, as the factory wiring is severly wacked. Question:: is the cruise controled off the transmission or through the computer or off the tach? Anyone w/info I would apprecieate help before I remove anything I shouldn't

John

Slonaker · 01-17-2006, 02:05 AM

If you mean how does it monitor your speed, I think it is through the speedometer. I hope it is not related to the ESC in any way since mine is not going back on the engine when it goes back in next weekend.

It does not really have a computer, BTW. I'm pretty sure the ESC just retards the timing when it detects knock (pinging).

Slonaker

locab36 · 01-17-2006, 07:14 AM

Your right on the ESC unit. I just wasn't sure as which the cruise monitored. I checked my manual for the 1985's and found it was stand alone. Also the lock-up on the tranny is stand alone as well according to the wiring diagrams, just needs a good vac source. I'm just not sure the 86's were the same. I don't remember seeing anything in the speedo cable that had wires. I'll check again.

John

piecesparts · 01-17-2006, 10:26 AM

The cruise control has a wire that goes to the back of the speedo and reads the revolutions off of the inside of the speedo. The control box for it is on the firewall just above the gas pedal and the wiring goes to the dashpot on the motor. It is NOT connected to the computer or the tranny, and you can actually throw the computer away and not have any problems with the cruise. I have two trucks with a standard HEI and 700R4 trannys installed (one is an 84 and the other is an 86). My 700R4s are not connected to any computer and I don't have lockup converters.

01-16-2006, 10:21 PM	#1
locab36 Registered User Join Date: Jun 2004 Location: Midland, MI Posts: 265	Cruise control on 86 Q's..... I'm working on a 86 SWB right now and as it waits for better weather for a 350c.i. transplant I have a couple questions. I will not be using the factory wiring/spark control(wiring cut by some PO). Just a plain HEI ignition. I want to retain the factory cruise control. It has the Vac dashpot w/the long rod to carb. Looks to have a vac line to the brake light switch for deactivation. Truck has the 700r4 tranny and I plan on a BTO conversion for my holley and tcc lock up, as the factory wiring is severly wacked. Question:: is the cruise controled off the transmission or through the computer or off the tach? Anyone w/info I would apprecieate help before I remove anything I shouldn't John __________________ Locab36 1936 low cab 1/2 ton 1956 BMW R25/3 1968 Moto Guzzi V7 1969 BMW R100/2 1986 Silverado SWB 2007 Harley FLHTP 2011 GMC SWB 4x4 Z71 http://www.flickr.com/photos/locab36...7623329816080/

01-17-2006, 02:05 AM	#2
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Cruise control on 86 Q's..... If you mean how does it monitor your speed, I think it is through the speedometer. I hope it is not related to the ESC in any way since mine is not going back on the engine when it goes back in next weekend. It does not really have a computer, BTW. I'm pretty sure the ESC just retards the timing when it detects knock (pinging). Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

01-17-2006, 07:14 AM	#3
locab36 Registered User Join Date: Jun 2004 Location: Midland, MI Posts: 265	Re: Cruise control on 86 Q's..... Your right on the ESC unit. I just wasn't sure as which the cruise monitored. I checked my manual for the 1985's and found it was stand alone. Also the lock-up on the tranny is stand alone as well according to the wiring diagrams, just needs a good vac source. I'm just not sure the 86's were the same. I don't remember seeing anything in the speedo cable that had wires. I'll check again. John __________________ Locab36 1936 low cab 1/2 ton 1956 BMW R25/3 1968 Moto Guzzi V7 1969 BMW R100/2 1986 Silverado SWB 2007 Harley FLHTP 2011 GMC SWB 4x4 Z71 http://www.flickr.com/photos/locab36...7623329816080/

01-17-2006, 10:26 AM	#4
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Cruise control on 86 Q's..... The cruise control has a wire that goes to the back of the speedo and reads the revolutions off of the inside of the speedo. The control box for it is on the firewall just above the gas pedal and the wiring goes to the dashpot on the motor. It is NOT connected to the computer or the tranny, and you can actually throw the computer away and not have any problems with the cruise. I have two trucks with a standard HEI and 700R4 trannys installed (one is an 84 and the other is an 86). My 700R4s are not connected to any computer and I don't have lockup converters.



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