1996 Ford Ambulance - AMP light on, and voltage/amperage meter going fubar

[huskyhauler]

1996 Ford E350 7.3L Turbo Diesel. Road Rescue model.

I keep the ambulance plugged into shore power with a trickle charger when parked. I brought it out of long term parking (hasnt been driven in 3 months) and the AMP light is constantly illuminated now. The onboard voltage/amperage meter is also going nuts with amp reading maxed out and the voltage reading hanging at 15/16.

Does that guage read battery output or is it reading the charging system?

Can anyone offer any insight on this and what the problem might be? Battery? Alternator?

 

[iggi]

Sounds like an voltage regulator / alternator issue. Don't know what ambulance module you have or how it's wired up but.. The battery won't put out 15-16 volts.

 

[Bikersmurf]

Voltage seems high. Is that with an ambulance package gauge or a digital multimeter? My gauge reads about 1/2 a volt high.
Voltage should be 15v max.
Amperage should drop to about 50 amps in 5-10 minutes.

many shops will test your alternator & batteries free of charge: also clean all contacts & connections.

 

[gtbensley]

I have a factory high output replacement alternator if you need it. Use a meter and test your output on the batteries while its off and also running. Sounds a bit high to me.

 

[huskyhauler]

Voltage seems high. Is that with an ambulance package gauge or a digital multimeter? My gauge reads about 1/2 a volt high.
Voltage should be 15v max.
Amperage should drop to about 50 amps in 5-10 minutes.

many shops will test your alternator & batteries free of charge: also clean all contacts & connections.

It's from the ambulance package gauge, the one that's built in to the center doghouse console.

I'll pop the hood and see if I can identify what alternator I have.

 

[huskyhauler]

I checked all 4 the batteries (2 engine and 2 house) with the vehicle off and unplugged from shore power and all 4 read 13.64 volts. I didn't have time to check with the motor running. I'll do that when I get home from work.

I was unable to see any identifying information on the alternator from above. Can anyone identify my alternator by this photo?

 

[Bikersmurf]

Mitsubishi 215 amp

32 lbs

last time I checked $956 cdn from Ford. No stock available in North America.

about $300 on eBay

 

[CaulkinsCo.]

The alternator only needs to make as many amps as you're using. Just put a standard unit in it, I'm guessing but I think around 130 amps and cheep.

Obviously if it's still being used medically and you have a endless budget then put another short lived expensive one back on.

Not running that's way high for voltage. Batteries might still be good but I would turn on some lights or something with it not running to bring them back down to around 12.5. also just guessing with that idea.

 

[huskyhauler]

I just checked the batteries with the motor running. 15.38 volts.

Rechecking the batteries after turning the motor off (1.5 minutes run time after sitting all night, and then starting) and they show 12.79 volts.

I use it for camper use and dont really use any ambulance related electornics or a lights.

Should I just go with the stock E350 alternator? I only drive this thing a few hundred miles a year so I'd prefer to not spend a ton of money. Anyone know if aftermarket alternators are decent or are they crap for this model?

 

[CaulkinsCo.]

Mine is a rebuild, I think at some level they're all a rebuild. You can cook the batteries by overcharging but it sounds like you avoided that so far.

Standard should be fine. It's more a issue of reserve then how fast you can charge them. Those take about ten minutes to change and can be had pretty much anywhere.

If you want to be more complicated you can add a standard unit, Amazon solar and a VSR for less money then a high output unit.

 

[iggi]

Personally I'd just get it rebuilt. Sometimes changing alternators leads one down a frustrating path of changing pulleys, brackets and more.

 

[huskyhauler]

Any recommendations on a good rebuild shop? In in the Seattle.

 

[Bikersmurf]

Not in Seatle. NAPA offered to rebuild mine for $450... but I'd lined up a new old stock OEM one for $300.

The mount to the engine is somewhat different between the alternator you have and a stock van one. I've read the van one can be modified to fit the bigger alternator... not sure about the reverse. It may be easiest to get a mount from a wrecking yard to fit the smaller alternator to the engine block. Also make sure the pulley is the same width as the serpentine belt (8 grove i think). Wiring won't care if you switch to a smaller alternator.

I'd start by cleaning all the ground connections to the alternator and + connections to determine if the voltage input the regulator is getting is lower due resistance in connections... the output is only about .5 v high. NAPA and other shops can test your current alternator.

A local rebuild shop can also test it and determine what would be needed to repair yours... or help you fit a lower output in it's place.

 

[huskyhauler]

I have the alternator unbolted and disconnected but cannot seem to wedge it out. Is this a coolant hose? Thinking about disconnecting it to see if it makes more room to get the alternator out.

 

[CaulkinsCo.]

I'm going to guess rear ac, if so do not disconnect. Might be able to disconnect support brackets to that hose and flex it out of the way.

It's been a year or so but I think I had to rotate mine in the mount to get it to fit out. Definitely not a pull straight up kinda thing.