[Glenn and Laureen]

1984 Newell Ignition Switch Wiring Questions
We need help in properly wiring a replacement ignition switch on our 1984 Newell Classic. Note:  This is NOT the original dash mounted ignition switch. This one is on the tilt steering column and is typical of a 1980s era GM vehicle (such as Chevy or Cadillac).

Our ignition switch was recently replaced by a mobile mechanic because the power signal to the starter was not disengaging after the RV engine was started. This was the source of the clattering that we recently had in the engine/starter. In addition, he replaced a relay at the very back of the coach.   Before the mechanic left everything worked fine, but shortly afterwards the switch quit working. So, he came back the next day to fix it, but was unable to get it working again in the time he had to spend on it that day. We decided to try to fix it ourselves.

It seems that somehow in wiring the new switch he had blown open the two terminals that he used for the starter, #8 & 9 in the image below (the two silver ones at the bottom). Power was on #8 and the starter wire was on #9. So, we bought a new switch and now need to figure out which terminals all the available wires should be connected to.

We don’t know where the wires should go because:  1) the wires are not in a harness; 2) we don’t know where they were on the original switch that the mechanic took out; and 3) we don’t trust where he connected the wires on the replacement switch he installed. We are being very cautious in hooking up the wires because we don’t want to damage any gauges or parts and create more problems for ourselves. We can start the engine with the remote switch in the back panel area but can’t drive it because the right rear has fallen and is resting on the tire. This happened right after we got the coach back to storage after the mechanic last worked on it.

The ignition switch is a Standard US105 part (bought at O’Reilly’s) that mounts on a tilt wheel steering column (see switch photos below). It has nine (9) terminals and we have seven (7) wires to attach.

       

After playing with the switch and looking at online videos, we’ve figured out what each terminal is typically used for in a car, but still have a couple of questions.

   

These are the 7 wires that were connected to this ignition switch:
1.      Blue – 13.7V
2.      Blue – 13.7V
3.      Blue – 13.7V
4.      Orange with black stripe – 13.7V. This goes to the battery voltage gauge.
5.      Red with black stripe – starter
6.      Orange – dashboard engine gauges plus a few other things
7.      Brown – should be accessories I think, but don’t know which ones. The radio and clock are connected directly to 12V and don’t go through the ignition
 
QUESTIONS:
1.      Power wires: 
-         Why are there 3 blue power wires? Why not just one?
-         Should all 3 blue wires go on the 3 center terminals #2, 4, and 6?
-         Are the blue wires from the house batteries and the orange w/black strip from the engine batteries?
-         Should the orange w/black stripe go with the starter wire on terminals 8 & 9 so the RV will be started with the engine batteries?
 
2.      Orange wire for the gauges - It seems like something somewhere has nearly shorted it to ground since there is only 2.5 ohms between this wire and ground. I disconnected all the orange wires that I could find to all the gauges, dashboard lights and switches and there’s still just 2.5 ohms between the orange wire and ground. Any ideas where to look next or is 2.5 ohms normal and we should just connect it to terminal 5 on the switch?
 
3.      Brown wire - what is it for, why is it grounded, and where should it go on the ignition switch? Normally, I think this is for accessories, but the radio and clock in this RV are connected directly to 12V and don’t go through the ignition switch. Is this wire connected to the levelling system? Our leveling system is not automated. It consists of four switches that move each corner up or down, plus the master on/off switch.

   

4.      Does the orange or brown wire go to the height control valves, the leveling system, or other parts of the air systems? If so, which terminal does it go on?
 
5.      If terminals #8 & 9 (the silver ones) are not used for the starter, are they used for something else?
 
Thanks for any help or insight you can provide.

Laureen & Glenn Parker

About us and our skill levels:  Laureen is a retired electrical engineer with an MSEE. She worked in microelectronics and has done a little bit on wiring houses but not on cars, RVs, etc. She likes to fix things. Glenn is a retired state bureaucrat and has a general knowledge of mechanics and a little electronics. We are willing to do any work that we are physically capable of doing once we understand what needs to be done and why.

We need to get this switch wired and working so that we can move on to figuring out why the right rear of the coach is down and won’t come up. The issues may be connected. One thing at a time…