[Dpetersenak]

So I am brand new to posting but have benefitted from diesel place for a while.

I have a 93 6.5 auto turbo diesel. It used to be an ambulance in Orlando upgraded by wheeled coach 1994.

I am the third owner counting the city of Orlando. I have it set up as a plow truck with front boss plow, rear drag plow and a hydraulic bed crane(recently removed, well I've pulled both plows too to fit in my garage). So my trouble began right around the time I took everything off to get it in the garage to work on it. (-32f isn't fun to hold tools in)

I pulled the plows and flatbed. Changed all my glow plugs my lift pump and batteries as all were in need. I knew I had a parasitic draw and chased it to my junction block (where it joined my wiring harness) 2 of my fusible connections seem to draw power (2.85amp) but only when both are hooked up. I'm quite certain one connects my PCM the other I do not know.

My main reason for posting though. I was quite careful in chasing wires and I cleaned all the grounds I could find while doing this. Originally I had a 190amp HEHR Powerline alternator (at first thought was bad but after lots of testing and even putting in a new alternator 1400$ ouch) my alternator produces no power. I'm running an external voltage regulator and have swapped in a tested good one so I'm guessing that couldn't be the problem. Numerous connections and grounds have been cleaned while I've been under it.

Does anyone have any advice on why the alternator isn't getting the proper signal to make power, or why it isn't making power (it's a brand new alternator)? Or what my parasitic draw off my junction block could be? I haven't checked voltage drop at all my connections yet but I have eliminated my plow wiring and all my fuses as the culprit.

I really appreciate any of the help I may receive. I'll post some pictures when I get a chance. There's mild aftermarket because of wheeled coach and plows/crane.

 

[57diesel]

Hard to tell whats going on on a customized custom truck. Typically the regulator gets its + turn on signal from a key on circuit via the batt/alt light. The regulator being always told to stay on would cause a battery drain. I would also assume that since it was an ambulance that it was either ordered with the 2nd alternator or one was added as part of the fit out. I wonder if maybe there is something complicated or strange going on in the wiring to control both of the alternators?

 

[Dpetersenak]

Hard to tell whats going on on a customized custom truck. Typically the regulator gets its + turn on signal from a key on circuit via the batt/alt light. The regulator being always told to stay on would cause a battery drain. I would also assume that since it was an ambulance that it was either ordered with the 2nd alternator or one was added as part of the fit out. I wonder if maybe there is something complicated or strange going on in the wiring to control both of the alternators?

Only one alternator, 190 amp HEHR Powerline 24-11. Has the two connection Ford plug with a battery and negative post on top. My batteries were bad but the alternator put out power until I pulled the bed/plows off. I'm relatively certain those had nothing to do with it. Beyond the wiring and alt setup there isn't much aftermarket. It's got some monster springs reinforced frame, FSD relocation and some other heat and longevity upgrades. It's still relatively a stock truck. I have never seen an illuminated alt light on this truck. Service throttle and engine cone on during start up but usually go away. Engine occasionally stays on but I haven't pursued that yet as it gave me no issues yet.

I was thinking that my +wire either has grounded out/or inadvertently become disconnected. To my knowledge the alt setup I am running should rely only on an ignition exciting wire via ignition source, battery pos and a ground? The parasitic draw I don't think is connected with this issue as I was experiencing it before I ripped everything off to get it in the garage. Does the PCM perform any voltage regulation? I also couldn't get my scanner to connect? The two could possibly be connected?

 

[56pan]

Any chance you could get wiring diagrams from the company that built it as an ambulance? Without one, it's about like looking for a dark spot on a black floor in a room with no windows at midnight. I know that's not much help, but you'll need those diagrams.

 

[OkDually]

Welcome to DieselPlace

 

[Dpetersenak]

Thanks OkDually.

I've tried a couple times reaching wheeled coach, with work and the time difference it's been challenging. I'll keep trying.
Hopefully I can find some time this weekend to chase the wiring down to give a diagram of what I currently have and also post some pictures. The plowing season is starting slow down up here for but I hate having my rig trapped in the shop. I'll get back once I dig into my wiring a little more. Thanks again everyone.

 

[smdk2500]

Does the battery light on the dash turn on when you turn the key on engine off? If i remember right I read some where that if that bulb burns out the alt wont charge. It might only be a gas engine forum.

 

[57diesel]

Historically speaking for GM since they started alternators the light bulb did have to be working for the regulator to turn on. I'm not sure when they quit doing that. I would guess 90s was still that way and it would not have quit till LED's which I would guess were well into the 2000's.

Now an interesting question is what if someone was to replace the battery bulb with an LED? I could see that being a problem since its doing more than being a light in this case.