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garyspang · 03-31-2016, 10:42 PM

It failed while parked at the Pickney Historical site in Mount Pleasant SC. I had no clue what the problem was. All accessories worked, but no dash display activity, no parking brake release, no starter activity. I tried to figure out where the power interruption occurred, but was so frustrated because all the fancy Workhorse Manuals were of no help and no internet. Next day I had it towed home.
Then I was able to research IRV2 and found out that another person had the same problem some time ago, and it was due to a failed starter switch. Now the manuals came in handy again for replacement instructions. Auto Zone had a replacement.
Working literally upside down with eye glasses and flashlight was strenuous but not an exercise in futility as experienced the previous day.
I also found out that Workhorse had a special retrofit to avoid such a breakdown. Now I am also very disappointed (PO'd) that they never send me any notification to prevent this certain pending failure on P32s ignition switch.
The attached pictures show the first spring loaded contact is held in a retracted state by molten and then hardened thermoplastic. There are no burned out contacts, only one that overheated enough to extrude the plastic into the clearance spaces. The stationary part also has discoloration around the first top right contact base.
Now my wife wants a new RV. She thinks I spend to much time fixing and maintaining the 13 year old and 145000 mile Sightseer. I tend to agree with her. Maybe the Ford Chassis has fewer bugs.

GraySeal65 · 04-01-2016, 05:43 AM

Amp bridging, very common on GM ignition switches in late 90s to early 00. To be honest as a mechanic I would't buy a GM, it seems like that's all I work on.

vettenuts · 04-01-2016, 07:02 AM

Can you please clarify where this is located, is it the key switch in the column? Want to make a mental note for future reference.

garyspang · 04-01-2016, 08:38 AM

It is a slide switch at the bottom of the steering column mounted out of sight in the back. I had to remove the lockout solenoid and dimmer switch assembly before the switch came out. A steel rod with a 90 degree bend at the switch is coupled to the ignition tumbler. Rotation of the switch causes a linear motion at the ignition switch. Many, many electrical events are at the slide switch with two connectors and eight contacts. From what I read, only the P32 seems to be affected.
Microfingers are needed to replace three screws and a nut along with 5/16 and 3/8 in mini-wrenches.

Oemtech · 04-01-2016, 05:37 PM

Parts & How To Link

vettenuts · 04-02-2016, 12:29 PM

If its P32 only then I guess I don't have it since I have the W24 chassis.

TandW · 04-02-2016, 06:38 PM

You haven't lived until this switch fails on you while you are in traffic. What a way to test your Park Brake as an emergency brake! Anyway, the P32 will always be buggy as a motorhome. Good luck!

tomwalt · 04-03-2016, 02:48 PM

Quote:

Originally Posted by TandW

You haven't lived until this switch fails on you while you are in traffic. What a way to test your Park Brake as an emergency brake! Anyway, the P32 will always be buggy as a motorhome. Good luck!

I've been following this post because I have an Allegro on a 1999 P32 (7.4/454 engine).
I can see my ignition switch and it looks like the one in the linked to photo (green plastic).
The specific directions for the fix state that it is for the 8.1 engine.
http://www.oemys-performance.com/med...on%20relay.pdf

Can anyone tell me if this is an issue and is this fix applicable to the 1999 P32 with 7.4/454 engine?

Oemtech · 04-03-2016, 08:25 PM

Quote:

Originally Posted by tomwalt

I've been following this post because I have an Allegro on a 1999 P32 (7.4/454 engine).
I can see my ignition switch and it looks like the one in the linked to photo (green plastic).
The specific directions for the fix state that it is for the 8.1 engine.
http://www.oemys-performance.com/med...on%20relay.pdf

Can anyone tell me if this is an issue and is this fix applicable to the 1999 P32 with 7.4/454 engine?

IMHO - it's kinda like termites... It's not IF you will get them - it's WHEN. If I had a P30 chassis this is one fix I would install. You can do it for probably $50 to $75 in parts, simple hand tools and couple of hours.

tomwalt · 04-04-2016, 08:00 AM

Will do - thank-you. I reference your web site quite a bit - thanks that too.

garyspang · 04-04-2016, 01:17 PM

I used my clip-on ammeter on the pink ignition wire and read 16.7 amperes. With only 0.05 ohm contact resistance, 14 watts of heat are generated (W=I^2*R). One can not cup hands around a 15 watt lightbulb and hold them there. This is a lot of heat energy. Omey's observation and suggestions are right on the money.

TandW · 04-04-2016, 05:06 PM

The coach builders added too much load to the accessory portion of the switch. Shed the load, and it will last longer. Some have used a relay to do this, but I feel that just further complicates things. Good luck!!

tomwalt · 04-04-2016, 07:12 PM

Quote:

Originally Posted by garyspang

I used my clip-on ammeter on the pink ignition wire and read 16.7 amperes. With only 0.05 ohm contact resistance, 14 watts of heat are generated (W=I^2*R). One can not cup hands around a 15 watt lightbulb and hold them there. This is a lot of heat energy. Omey's observation and suggestions are right on the money.

16.7 amps is a lot of added current. Replacing this 16.7 amp load with a few milliamps to pick a relay seems like a good fix. Of course this 16.7 amps could be higher with additional loads running at times (thus the 40 amp fuse).
I was looking at this today and my only issue is I have a significantly different fuse block that does not have the 'A' or 'B' terminal, so I'm thinking of using an inline fuse and using a spare 'always hot' terminal I have available on the house battery side.

Quote:

Originally Posted by TandW

The coach builders added too much load to the accessory portion of the switch. Shed the load, and it will last longer. Some have used a relay to do this, but I feel that just further complicates things. Good luck!!

Adding a relay is adding another opportunity for a failure, but I don't know of a simpler way to use/tap that 'pink wire output to accessories' into a "Hot in Run and Crank" power source that would handle this kind of amperage (40 amps max).

Any inputs are appreciated - let me know if I'm doing something stupid or if there is a better way.

garyspang · 04-05-2016, 08:50 AM

Hi Tom
Only during starting did the current go to about 19 amperes for a second. All other times it hangs around 16.7 and changes up and down about one amp, but never long enough to get a steady reading on a digital display.
No matter what additional stuff I turned on, and I tried every switch on the dash and the radio, the 16.7 amp average reading was not affected.