Help me ambulance mechanic please!

[blackturbo]

Hi all,

I have an 1990 ford e350 type III ambulance with the mccoy miller box. I purchased this 3 years ago at an auction to haul 4 wheelers around in and cause it was cheap and in good condition. the last two trips out in it has been 4 hours each of driving. in the middle of the first trip, i noticed the volts and Amp gauges on the main panel were reading negative and not charging. I got it home and parked it for 2 weeks.
the second trip, started it, and the amp and voltage gauges were reading good charge, about an hour into my trip, they went down to the minus again, and the low voltage light came on.. and it never came back. So tonight, I unhooked the alternators main power wire. tested the power wire with batteries on and got voltage. then started it up, and tested the plus side on the alternator and got no voltage. Is the alternator gone? I noticed a small box on the alternator with a smaller wire going to it, and a plastic screw to turn something up and down. Is this part of the alternator or some ambulance stuff. thanks for the help!
Mark

 

[Achilles]

When you're driving done the road, do you notice a drop in power when you stop (eg. Lights dim, blower turns down) and then go back up when you drive again?
Does it have 2 alternators or one?

 

[Metro EMS News]

Mark, that might go to, or be a part of the load manager. This distributes the electric load more evenly when the ambulance is using significant sources of power. Like Achilles asked, does your ambulance have 1 or 2 alternators? If 2, one alternator may be going bad an influencing the electrical load.
Best of luck.

 

[blackturbo]

it only has one alternator. You used to be able to watch the voltage and amperage go up and down, depending on how fast the engine was idling. slow to a stop light at idle, and voltage dips below 12 volts, then when u rev it , it goes back up. now it doesnt do anything, or charge anymore.

 

[blackturbo]

what is this box looking thing on the back of the alternator for? is this seperate from it,, its got a small gauge wire going to it, and has a plastic screw on top looking like you can turn something up or down. I guess its part of the alternator too and doesnt have a name to it? thanks guys!

 

[Achilles]

it only has one alternator. You used to be able to watch the voltage and amperage go up and down, depending on how fast the engine was idling. slow to a stop light at idle, and voltage dips below 12 volts, then when u rev it , it goes back up. now it doesnt do anything, or charge anymore.

sounds like an alternator...

 

[blackturbo]

Ok, thank you, . I hate to see the price of a new ford one, I was thinking about going to a lower amperage but i have all the lights still and their fun to play with while camping. thanks again guys!

 

[Household6]

Your rig has an external voltage regulator.. I believe they are special just for an ambulance package. ($100+ to replace) Likely it also has an external rectifier/diode. (cheaper to replace)

I'm guessing, but that black box could be a battery isolator, just a simple junction box to make testing easier for the technician. No functional use, just meant to confuse everyone.

 

[socalmedic]

your alternator is bad, go to the parts store and get a $100 alternator. no need for a ford part. you should replace your voltage regulator at the same time, about $30. all this can be done with simple tools, IIRC 9/16 socket, ratchet handle, 6" extension, 1/4 socket.

 

[mycrofft]

Send photo.....

 

[Too Old To Work]

From the vintage of the ambulance, I'd guess that it's not a Ford alternator, but one made by Leece-Neville. They made aftermarket heavy duty alternators for fire trucks, ambulances, and other special purpose trucks.

You'll know because it will say "Leece Neville" on the casing. It's been a while since I looked at one, but that box you describe sounds like the external regulator. Heat killed them, so if you have a gas engine (it's kind of late for that, but slightly possible) cumulative heat could have caused it.

Unless you need the extra amperage that the Leece-Neville alternator provides you should see if you can get the OEM brackets and wiring and refit it to the pre conversion configuration.

Is it a dual battery set up?

In 1990 there was no load manager available from anybody. OEM alternators couldn't handle the current needs of the electrical system, so the only two alternatives were a dual OEM alternator system OR a Leece Neville afternarket unit. Some manufacturers used one system, others used the other. I think the Leece Neville units were close to $1K, but I'm not sure since I didn't have to sign the checks. Dual batteries were also pretty common and the ambulances had to have an isolator to keep them from cross drawing. Some some ambulances still have the Cole Hersee dual battery switch as well. That's a big switch with a big black knob labeled "Off" "Batt 1", "Batt 2" and "Both". Those were originally designed for marine applications, but were very common on ambulances into the mid to late 1990s. Very little to go wrong with them. In fact I've never seen one go bad.

 

[blackturbo]

Ok thanks guys with the alternator problem. now for the next.

Torque converter lockup/ and unlock..


I dont think this is happening on the highway and iam slowly burning out the transmission. Is there a cable for this or switch on the gas pedal? or how does this engine and transmission lock and unlock . thanks Also I have a cable that is not hooked up, near the injection pump *the kind of cable that looks like one attached to gas pedal) that looks like it goes on the throttle linkage somehow. its either for the cruise control, or something..
Mark

 

[Too Old To Work]

IIRC, torque converters lock up automatically based on engine rotation. But, it's been a long time.

That cable might be for a high idle device. That used to be controlled by a manually operated knob on or under the dash, but mostly by the late 80s, that was done automatically by an electronic device.

Ok thanks guys with the alternator problem. now for the next.

Torque converter lockup/ and unlock..


I dont think this is happening on the highway and iam slowly burning out the transmission. Is there a cable for this or switch on the gas pedal? or how does this engine and transmission lock and unlock . thanks Also I have a cable that is not hooked up, near the injection pump *the kind of cable that looks like one attached to gas pedal) that looks like it goes on the throttle linkage somehow. its either for the cruise control, or something..
Mark

 

[blackturbo]

thanks for reply theres a mechanical high idler device on the rear of the motor that is vacuum operated and has a chain (like you see on a pen at your banks counter top) to the throttle linkage to control the high idle thing (thats why i always wondered why ambulances would be running high rpm with nobody in them lol ) but this is a cable (black, with a wire thru it) like the throttle cable to the gas peddle, and its not hooked to anything, and looks like it broke off something that attaches it somehow to where the throttle cable is hooked up too (the injection pump?) . ill take pictures tommorrow .
mark

 

[Too Old To Work]

I remember those vacuum controlled high idle devices well. Not fondly, but well. The other cable might be for cruise control, if the truck has one. Other than that, I'm not sure.

thanks for reply theres a mechanical high idler device on the rear of the motor that is vacuum operated and has a chain (like you see on a pen at your banks counter top) to the throttle linkage to control the high idle thing (thats why i always wondered why ambulances would be running high rpm with nobody in them lol ) but this is a cable (black, with a wire thru it) like the throttle cable to the gas peddle, and its not hooked to anything, and looks like it broke off something that attaches it somehow to where the throttle cable is hooked up too (the injection pump?) . ill take pictures tommorrow .
mark

 

[blackturbo]

but my friend and me agree that is not locking/unlocking on the highway like it should ..and after trips i have bubbles in the tranny fluid showing its getting hotter than it should. the tranny was just replaced 20 thousand ago, but i dont know what it is..

 

[Too Old To Work]

There used to be a cable that attached to the throttle and ran to the transmission. It was supposed to shift the transmission into a lower gear when you floored the accelerator. That improved low end acceleration. I just don't remember them on ambulances. Which doesn't mean that they didn't have them, just that I don't remember them.

There was a name for that cable of course, but I don't remember what it was.

If your transmission is over heating, you need to look at the transmission cooler as well. A lot of heavy duty applications, like ambulances, had separate coolers. The were essentially small radiators located in front of the regular radiator. If your truck doesn't have one, you might be able to add one. If you do have one, it might be clogged up, although with a recent rebuild of the transmission the fluid should be OK.

Have you talked with whoever did the tranny rebuild?

but my friend and me agree that is not locking/unlocking on the highway like it should ..and after trips i have bubbles in the tranny fluid showing its getting hotter than it should. the tranny was just replaced 20 thousand ago, but i dont know what it is..

 

[blackturbo]

no, i dont have any information, other than a sticker on it saying reman for ford. but also, I wanted to see if you knew anything electrical. as most of it was gone , as in inverters and the other stuff. I want to be able to power the "patient area" with dc power to run the ceiling lights and stuff when iam parked, without having to use the two batteries for the motor. I have a pyramid 50 amp power supply. can I just hook this to the power wires where the inverter used to go? and if I do this, and turn the battery switch on,, will the pyramid charge those batteries? thanks..

Mark

 

[Too Old To Work]

no, i dont have any information, other than a sticker on it saying reman for ford. but also, I wanted to see if you knew anything electrical. as most of it was gone , as in inverters and the other stuff. I want to be able to power the "patient area" with dc power to run the ceiling lights and stuff when iam parked, without having to use the two batteries for the motor. I have a pyramid 50 amp power supply. can I just hook this to the power wires where the inverter used to go? and if I do this, and turn the battery switch on,, will the pyramid charge those batteries? thanks..

Mark

The inverter was for powering AC equipment, not for powering anything on the ambulance. You should see a couple of regular house AC outlets mounted in the module. To do what you want, you'd have to do some rewiring of the circuit board of the module itself. As originally built, the power for the module was drawn from the charging system of the vehicle.

The only exception to that would be if your ambulance was built by Frazer. I'm not sure they were making ambulances back then, but they had a generator that powered the module and warning lights.

 

[blackturbo]

well iam saying, where the stock inverter was mounted, theres two large copper cables, black and red, that supplied the 12volt dc to run the inverter. so if I hook anything ,like a battery charger. it should energize the 12 volt dc system ,just like using the batteries.. does that sound right