KeithO

An acquaintance told me that there might be a known problem with the factory wiring but couldn't provide details. I have been googling for hours and have found nothing.

Background:
In November, I purchased an enclosed trailer for my race car and towed it back empty from Tennessee to Western PA with my 2001 Tahoe, using the Hoppy Impulse brake controller installed. I also purchased the custom cable that ran from the connector under the dash to the controller.
http://www.hopkinsmfg.com/37235.html
Everything worked fine.

During the drive, I quickly realized that the 5.3L/4L60 would die a fast death once I tried to tow with my race car in the trailer. So, very recently I purchased a 2004 Suburban with the 8.1L/4L80e with the factory tow package. Tows quite well with the car in there.

Since the part numbers for the brake controller were the same for the Tahoe and the Suburban, I simply moved the controller and wiring from the Tahoe to the Suburban.

The wiring is messed up. The most obvious thing is that when the headlights come on in the Suburban, this actuates the brakes. The left turn signal works OK on the trailer but the right turn signal is very weak. I haven't had a chance to check other items due to lack of help from other family members (they don't like my racing very much, so they won't help).

Because I have to store my trailer at a storage location, getting the Suburban and trailer together takes time (that is hard to come by).

When towing, in order to get where I was going, I just turned the gain down on the brake controller and only ran with the Suburban brakes. This is not my preference. In addition, I am uncomfortable knowing that the lights are not working properly.

I have been working non-stop for a year to get my race car ready for competition (tons of time and money that I don't actually have). I am registered to run my first races this weekend. I would really like to have this fixed by then.

Are there any known issues with the 2004 Suburban wiring? Or am I just going to have to come up with a structured plan and re-wire the trailer side to accommodate the non-standard pinouts on the Suburban? Or should I start to suspect my trailer?

My acquaintance seemed to think that there was some problem with the harness installed at the factory? Wrong year harnesses or something?

Thanks.

KeithO

Wait a minute...

I went and rechecked the custom wire part number for the Tahoe/Suburban here:
CHEV/GMC Plug-In Simple® Brake Control Connector 99-06 :: Hopkins Towing Solutions

It appears that I need to move a wire on the connector. The instructions are incomplete but it appears that the requirements changed in 2003, which would explain why my 2001 works fine but not my 2004.

I'll report back.

73shark

Welcome to the forum.

I've never heard of a wiring harness problem before. But sounds like you may have found the problem.

What kind of race car?

KeithO

Thanks for the welcome.

I wanted to mess with it last evening but I had to work late and didn't feel like dealing with it when I got home. Hopefully tonight, but I won't be able to really test it until I pick up my trailer on Saturday morning.

My latest money pit is a "retired" NASCAR Busch Car - ~1990 Olds Cutlass body with a SBC. Since there is no Haynes manual for this car, I took most of these pictures for documentation purposes:
Ex-BGN Stock Car - Road Race pictures, photos, and videos, from motor sports on webshots

In case it's interesting, here is a video a friend of mine made while we were at a lapping day at the track last Sept. It was still a roundy-round car then and was a real handful:
http://www.youtube.com/watch?v=rHA9IXkky1s
It's still scary fast.

I have been updating it for current safety specs and for road racing. I was told it was a road race car but I don't think it was. Saturday is my first track session since last year, I have made a tons of mods, I don't know what I have and this is an actual race... Ought to be interesting.

73shark

Nice looking car. Seemed to handle pretty well in the video, especially for a big car w/ a SBC in it. Good luck this weekend. Let us know how it worked out.

KeithO

This car has been what I have always wanted since I was a child. This will be my last race car because there is nothing else that I want after this. It has been 12 years of escalation to get to this point (starting with an L98 88 IROC that I bought with the proceeds from the sale of my old beat up 69 Camaro). This weekend will be quite an experience if she holds together (I have no idea since I haven't been able to test).

The good news for this thread is that I modified the wiring in the 'burb last night after work. I suppose I'll learn if this was the problem when I try to tow to the event on Sat. morning.

Let's see what happens.

73shark

Did you race the IROC? I had two '87 IROCs. Nice cars. From what I've seen, they weren't to shabby on a road course if setup properly.

Let us know how the wiring & Olds does.

novaracer1

This is very cool. I really like the little gadget that shows the weight transfer of the car as it accelerates and decelerates thru the turns.

KeithO

I mainly autocrossed the IROC but by that time (early 2000's) the LS1 came out and I was outgunned. I sold it and a 83 Monte Carlo SS to get an LS1 Camaro and started winning alot.

Even so, the IROC was a blast at lapping days, it's light weight made it easier to drive fast and they still haven't ever made a better looking Camaro (IMO). Here is my old IROC at Watkins Glen at a lapping day:

I still miss that car.

Anyway, I bought a used GoPro SD Camera and plan to test it this weekend. I already mounted it so it should be ready - but I have no data logger.

Those data loggers are great. I can't afford one but someday (once I pay off all the stuff that I bought for this car) I hope to get one. Right now, when I rip off a good lap, I don't really know where or why I found the speed but with one of those, you can find out.

73shark

I agree about the design. Just looked mean and fast. Autocrossed my '73 Corvette 'til the '84s came out and since they handled like a slot car, I decided to retire.

What was the data screen it shows in your video?