'72 Crown - No start from the drivers seat

Shining Finger · 10-30-2018, 06:17 PM

Crown Gurus!

Okay, so this bus was almost free. 72 with Detroit 671 turbo, RT910 transmission. Ive been able to jump it off the starter, no start on the ign. switch or the start button. Neutral safety switch or run relay? Everything comes on when I jump it, fires instantly. I can choke it from the cab to shut it down. Im just not so sure what to do to track the fault....also, in the engine compartment, there are two push-pull type switches, which could be the culprit, since both are rusted solid in the depressed position (inward). The button does nothing. The panel has been painted over, so any indicators are hidden.

Otherwise, the bus runs amazingly. 89,000 miles on rebuilt engine, and there is a WVO conversion in situ but bypassed. Some things werent completed, which may have led to my acquisition of it.

Iceni John · 10-30-2018, 09:52 PM

The two push-pull switches are for Ignition and Safety, and both need to be pulled out (on) for the engine to start from the engine start panel. The Start switch is a momentary-on push switch. If they're seized solid, you need to replace them. Cole-Hersee probably made the originals, and still makes those switches now. Just don't use cheapo Pep Boys switches - a Crown deserves better!

You say you can choke it from the front to stop it. What exactly are you doing? I hope you're not using the emergency stop flapper on the engine's air intake, otherwise you'll be looking at replacing all the blower seals soon.

There's a Crown tandem electric schematic on eBay now. It would be a good idea for you to buy it!

Where are you located?

John

Shining Finger · 10-30-2018, 10:17 PM

Hi John! Thanks so much for taking the time to ponder a little.

I checked out Cole Hersee, looks like theyve been bought by littlefuse... I would like to replace them.

On the panel to the left with all the switches are two buttons, labelled START AND CHOKE. There is an emergency stop button, but ive not noticed that it does anything, as well as the neutral bypass, zilch. I've only run the bus a few times, shut it down with the choke.

The bus was parked in Santa Cruz for a while, so theres some corrosion, but so far all ive had to do was repair a cracked fuel line.

Shining Finger · 10-30-2018, 10:24 PM

Oh yes, I'm in Covelo, wild West California. Planning to move to a warmer climate, so if possible Id like to get some of these issues sorted out. I rigged up a remote starter switch so I dont have to jump it with a screwdriver, though to the novice it seems like magic. If i have to, i could bypass, and there is a junkyard with a few Crowns, so if i need something special...

Iceni John · 10-30-2018, 11:59 PM

If your bus has a switch marked Choke, it originally had a Hall-Scott gasoline engine. Are you sure it's a 1972?

It looks like you have a good winter project ahead of you, restoring all the bus's entire electrical system to something approaching original and otherwise undoing the ravages of time and the misdeeds of unsympathetic previous owners. Good luck! Are you a member of the Crown Coach Junkies group? They're now active only on Facebook - their Yahoo forum is now essentially defunct, which is a pity because I, and some other CCJ members, do not do Facebook at all; I refuse to feed the monster it has become.

John

Shining Finger · 10-31-2018, 12:20 AM

On the panel, both my 1961 and 1968 Crowns had two buttons. Start and choke. On the 61, the PO didnt even know what those buttons did, he always jumped it to start it...the 68 never did have a key ignition that worked. Im thinking its the run relay behind the panel...key should switch on, trig relay to power everything up. Key on affects only lights and so on, but does not shut off the bus or start it.

cowlitzcoach · 10-31-2018, 01:41 AM

The engine compartment switches both have to be in the run position for the driver's compartment key switch to work.

A picture of the switch panel will tell very quickly if what you have is a 1972 or a bus much older that was re-powered to a DD. The more common re-power from the Hall-Scott was to the Cummins 220. The 220 was basically identical in length so motor mounts were in the same place, the bell housing would fit, and the same driveline could be used.

I am having a hard time remembering what the 1972 panel looked like but I don't remember the choke button. On my 1968 the choke button was there but it wasn't hooked up to anything. I am wonder if someone wired up the choke button to activate the throttle shut off. On most of the DD's the shut off was air activated. If you started the engine with no air pressure you couldn't shut it off from the driver's position until you had at least 90-100 PSI--until the first (wet), second (rear), and third (front) tanks got at least 90-100 PSI the fourth tank (accessories) won't get any air pressure.

As far as other issues in regards to starting, when the driver's key is turned on a relay in the front electrical panel will activate allowing power to go into the start/run circuit. I had one go bad on my 1979 Crown. If you didn't hold your tongue just right when you hit a bump the engine would quit. Sometimes it would restart right away and sometimes it wouldn't. It was a devil to diagnose, as in find which solenoid was causing the problem.

The way in which you are starting it makes it difficult to determine where the juice is getting lost. Both the manual and automatics had neutral safety switches. The manual transmissions needed them as well because it was required in some places so it became standard on all manual transmission Crowns--less expensive to put it on all than to only put it on a few. Your Crown since it has a manual should have a neutral bypass switch on the dash that will bypass the neutral safety switch and allow the starting circuit to get hot. If you have a bad neutral safety switch and a faulty bypass switch it could explain why the driver's switch doesn't work.

I suppose the first thing to do is to replace the engine compartment switches. Until you know they are working it will be very difficult to find where the juice is getting lost.

Good luck and keep us posted as to your progress.

Shining Finger · 11-04-2018, 11:29 AM

Thanks Cowlitzcoach, i think you nailed it. Until replacing these switches, it'll be hard to troubleshoot.

A photo of the engine bay side, they sprayed the panel, but i can see a vague ghost that says "start".

The panel, now im forgetting which ive been using...the left or the right? I thought the left, which is labelled "start"...hmm...

And i was looking for some aluminum plate for my stairwell, turned out this road sign fit perfect when I cut it up. Just enough to trim it out too.

You may also like: