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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: nitehawk on August 20, 2016, 09:40:02 am

Title: Cruise Control "drops" 10 MPH
Post by: nitehawk on August 20, 2016, 09:40:02 am
The original cruise control on our '89 GV was replaced with another "original" cruise control from Mike Grimes just before we took possession of the coach five years ago.
The electronic module is located under the dash and on top of the steering column. It used to only drop about 5 MPH, but now it is about 10.
Performance is erratic. There are times it just doesn't work--for long periods of time, then suddenly it works! Wiggle the wires and it will work--again.
Is there an adjustment? If so, where?
Title: Re: Cruise Control "drops" 10 MPH
Post by: wolfe10 on August 20, 2016, 09:40:57 am
Norm,

What system is it? Bendix?
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on August 20, 2016, 09:43:45 am
How do I find out?
Title: Re: Cruise Control "drops" 10 MPH
Post by: wolfe10 on August 20, 2016, 10:11:49 am
Should be some kind of identification on the box.  Bendix and Rostra were common brands during that time period.

Have you tried engaging the cruise, but keeping the speed steady for an additional minute with the accelerator to see if is just slow to engage?
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on August 20, 2016, 10:57:25 am
Not for a minute, but I do keep my foot on the pedal until I sense the cruise is working. This I usually do by watching the tach. Little or no drop means the cruise is engaged.
Title: Re: Cruise Control "drops" 10 MPH
Post by: John Duld on August 20, 2016, 12:21:45 pm
If it works when you wiggle the wires making any adjustment is not the solution. You need to find the bad connection.
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on August 20, 2016, 12:29:03 pm
OH, OH! Looks like I will be standing on my head in order to see up under the dash. Not good because of these darn bifocals. Either things are too far or too close!
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on October 04, 2016, 08:41:44 pm
Well, I went out two weeks ago (or thereabouts) and decided to take Brett's advice regarding a possible loose wire.
What I found just blew my mind. To think that the Kenworth garage would do such a crappy job was astounding, to say the least!! They used the blue butt splices to connect to one side of the OEM plastic six pin connector. On the other side of the mating connector were five wires and a jumper, and all were about 28 Ga or smaller.
The yellow wire on the control box went to a open hole, one without a corresponding wire on the other connector.
I eliminated the OEM plastic connector and the six blue (16 Ga) butt splices and wired the whole thing together. Finally got to test it last Tuesday and the cruise works like it is supposed to!! Engage, Set, on/off, Decel, Resume, and increase!!
Hopefully all that sporadic, occasional functioning is behind me. Five years of sometime functioning!! And back to Kenworth twice to fix the problem.
Once--OK--many times---heard it said that if you want it done right, do it yourself. In this case------------TRUE ^.^d
OH, and first time after increasing speed control, the cruise went up 4 MPH over my set point. Yesterday I reverse rotated the screw and now only 2MPG gain. I think I will let it alone now.
Title: Re: Cruise Control "drops" 10 MPH
Post by: John44 on October 04, 2016, 08:46:09 pm
Think the key words there were "Kenworth garage", not electricians.Usually my rule of thumb is if you can nothing beats solder.
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on October 04, 2016, 08:53:39 pm
The two visits to the KW garage were by the RV dealer where we bought the coach, and covered by their warranty, so just aggravating but cost free.
Title: Re: Cruise Control "drops" 10 MPH
Post by: TulsaTrent on October 04, 2016, 11:10:19 pm
I eliminated the OEM plastic connector and the six blue (16 Ga) butt splices and wired the whole thing together.

What did you use to connect the wires?
 
Thanks,
 
Trent
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on October 04, 2016, 11:16:00 pm
Intertwined the wires, then twisted them doubled, then solder, then shrink tape.
Title: Re: Cruise Control "drops" 10 MPH
Post by: krush on October 04, 2016, 11:23:54 pm
There is nothing wrong with good crimps that are properly installed with a good tool. In fact, many argue they are better than solder. The key is GOOD crimps and a good tool!
Title: Re: Cruise Control "drops" 10 MPH
Post by: nitehawk on October 05, 2016, 06:22:57 pm
Reason I didn't use crimps all the time? The EXTREMELY small wires on one side.
What I did (and usually do) when I have very small wires is to strip off extra wire insulation on each wire, then mesh the two ends together after sliding on the shrink tubing, twist the wires and then lay the "assembled" wires along the smallest wire axis after soldering. Then I slide the shrink tubing over the splice and use my heat gun. Now there is little or no stress put on the smaller diameter wire. The load is put more on the larger gage wire and the insulation of both wires.
I have yet to have a failure from this type of connection (knock on wood) and the smaller gage wire is no longer the weakest link at the splice.