wiring harness

[snowball]

Hi all,

Just wondering if anyone has done a wiring harness replacement, How bad is it ? and what it costs.

Also does the dash need to be removed or any other major items.

Thx

[Wwes]

In your suburban? I see those all the time on ebay.

It's easy once you get into it - just take your time and mark everything.

What's the problem with the harness now? Maybe something that can be fixed with a wire repair or two?

[snowball]

Yeah. On the old beast.

2 issues. 1, the line the connects to the proportioning valve grounds and turns on the dash light. Not a big deal until I try to get it inspected

Also under the column it's been hacked to death. It didn't come with cruise, and it's been spliced and vampire tapped. Last week I was pulling my hair trying to get the brake lights to work.

I'm worried when my wife and kids take it. I'm thinking of just replacing it all.

When you say ebay, is that new or used?

[snowball]

And the connectors are crumbling.

[hatzie]

Cruise is a sub-harness that's installed in addition to the main harness. You should be able to liberate the 88-94 GMT400 chassis Electromotor cruise setups and adapt to a 1990 1991 RV Suburban fairly easily.

What do you mean by crumbling? The Delphi Packard and Pak Con automotive connector shells are made of high density polyethylene. HDPE has a lot of give to it before it breaks... it's not very brittle even after repeated abuse with petrochemicals and ozone. Overheating will do it but they'll look burned. I have seen connectors that look like mice chewed on them from amateur electricians attempting terminal removal without guidance. Got any pictures of how they are damaged?
Corroded terminals can be dealt with fairly easily. Mouser and many others sell all of the terminals and the connector shells that are still in production... most of the shells are in production or at least still stocked items.

How many wires are damaged? It usually looks a lot worse than it is.
5-10-15 or even 20 wires can be spliced and covered with heatshrink. Scotchlok tap damage can be repaired with liquid electrical tape as long as the wire strands aren't damaged. The short runs can be simply replaced with new SXL wire in the appropriate American wire gauge and terminated with brandy new terminals that slide right into the connectors after you extract the damaged wire and terminal.

The new cab harnesses from American Auto Wire and Painless among others are usually more trouble than installing a used harness... you have to terminate a lot of connections to mate with the factory bits you are plugging into.

If you buy a used harness lay it out on a floor or sheet of plywood and examine it for damage before you install it. That way you can execute repairs without being twisted into a pretzel under the dash.

Power Windows/locks and AC are sub harnesses that are separate from the main harness...
Power glass and rear AC are some more that can be sourced separately as well.

[snowball]

My cruise is a franken-cruise. the module connects to a weird servo. It sits over the driver wheel well and has a non standard connector. I want to put a standard servo and wiring. Under the dash the brake switch has vampire taps on it. It did not come with a cruise but the brake switch is a cruise type.

Both injectors, the ECM, Distributor, and O2.

I'll check out those connectors and wire. thanks!!!

[snowball]

How do I find the terminals and connectors in Mouser?

[hatzie]

The stock 80's Cruise III is not easy to retrofit and many of the parts are not available anymore.

Look in the wiring diagrams for the wire gauge and color... if you care about matching the original colors. You definitely need the correct wire gauge and I usually pick the heaviest crosslink Poly jacket I can get... SXL.
The actual GM Delphi connector numbers for things like the brake light switch are in the wiring diagrams as well... usually right next to the representation of the connector. Just google the number. Usually you'll find Mouser Electronics and Newark and Del City and Waytek in the list of hits. Some of the more common connectors and real Delphi Packard tooling are available from a mom-n-pop outfit named TheElectricalDepot.com

[Wwes]

Hatzie, care to expand on this -> You should be able to liberate the 88-94 GMT400 chassis Electromotor cruise setups and adapt to a 1990 1991 RV Suburban fairly easily.

I'm getting ready to fix the Cruise III in my 83 and this might be the way to go for me.

[hatzie]

Cruisemaster from the 70's & Electromotor from the 90's are simple and easy to retrofit. Cruise III is a complex beast and the parts are getting scarce.
The electromotor cruise control is a GM branded Delphi servo motor box with a throttle cable and several electrical terminals on one 10 terminal Metripack connector. Be sure to get that Metripack connector... It's an oddball Metripack 150. The electromotor cruise is not a difficult retrofit. It's similar to some of the more expensive Rostra units but uses genuine GM parts.

GM used this electromotor Cruise box on the cable throttle RWD V8 and some V6 vehicles in the 1990s and some late 80's rigs. Fly by wire ended its' use.

This is the service training manual that you can find in the manuals thread.
https://www.mediafire.com/file/3e6k8...se_Control.pdf
The 95-01 6.5L Turbodiesel guys used this unit to re-install cruise when they switched from the DS4 electronic throttle to the 4911 DB2 cable throttle injection pumps. There's a writeup on The Dieselpage on how to use this cruise module but you need to be a member to read it.
There are several writeups on the F-Body boards and Pinnocks Fiero boards... Google is your friend.

The Seven inputs are...

1. Ignition-Power.
2. Ground.
3. On/Off.
4. Set/Coast.
5. Resume/Accel.
6. Brake/Clutch.
7. 4K VSS....You can get this from the cruise terminal on the green VSSB on the back of your 1981-1991 CK RV cable speedometer or the DRAC cruise terminal. GM fed Cruise III and some throttle body ECMs using the VSSB optical pickup and buffer box arrangement. It can be added to any 80's GM cable speed head with the slot and screw hole present on the back of the speedo housing. The Electronic speed heads on the last RV models used a DRAC and VSS in the transmission or transfer case.

The stalk switches for on-off set resume etc should be fairly adaptable. You can use the stock 83-91 CK/RV stalk or the 88-93 GMT400 CK stalk. As far as the multifunction cruise switch stalks go... they used essentially the same Saginaw steering column. You can use the 88-94 T400 CK wheel on your CK RV squares. The switches are similar enough that they could be adapted but the stalk actually fits either model... I've used an 88 CK stalk on an AMC Eagle. Same column in some respects.

Some of the LO3 & LO5 V8 RWD B-Bodies ( Caprice ETC ) had the Electromotor cruise. I've never looked at a 90 or 91 RV series with cruise... Those may no longer have the older Cruise III system either.

[snowball]

Hatzie,

I just want to say you're a wealth of information and I really appreciate it.

Since I already have the stock, and the module, I'm going to look for a wiring harness, servo, bracket and throttle cable connector and see if it all works.

[hatzie]

The Cruise III Training Manual is in the manuals thread too.
It'll give you a good overview of what you're looking at before you jump in the deep end of the pool... If yours uses the later electromotor unit it's much easier.