Voltage Problem, reverse problem
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Voltage Problem, reverse problem
Hi everyone! great forums here, i read posts on a daily basis!
On with the situation. I have a 1998 Ford E 350 7.3 Powerstroke ambulance. I purchased the vehicle this week after it was sitting, unstarted for 1.5 years minimum. Truck starts up and got new batteries in. The guy i bought it from said it needs a new alternator. When started, it shows 16 volts and has a battery light on the dash. I took the alternator out and had it tested at autozone who said it tests fine. I cant figure it out. I inspected the battery cables as much as i can and everything seems in order. I tried grounding the alternator to metal and negative terminal hoping it would be a bad ground, no luck. I cant find an external voltage regulator, but i;m not sure where to look. Also, the truck stalls in reverse unless you give it steady throttle, unsure if its related.
Thanks in advance for any help!
David.
On with the situation. I have a 1998 Ford E 350 7.3 Powerstroke ambulance. I purchased the vehicle this week after it was sitting, unstarted for 1.5 years minimum. Truck starts up and got new batteries in. The guy i bought it from said it needs a new alternator. When started, it shows 16 volts and has a battery light on the dash. I took the alternator out and had it tested at autozone who said it tests fine. I cant figure it out. I inspected the battery cables as much as i can and everything seems in order. I tried grounding the alternator to metal and negative terminal hoping it would be a bad ground, no luck. I cant find an external voltage regulator, but i;m not sure where to look. Also, the truck stalls in reverse unless you give it steady throttle, unsure if its related.
Thanks in advance for any help!
David.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,731
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From: SE Florida
You should get the alternator tested by a place that knows how to test alternators. An alternator that is outputting 16 volts is bad.
Check the trans fluid level. Low fluid can cause stalling in reverse.
Check the trans fluid level. Low fluid can cause stalling in reverse.
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I need to get my OBD scanner hooked up. Guess I should have tried that already lol. Last I checked the fluid level was acceptable. Needed maybe 1 or so quarts but need to get some more mercon, ran out. I didn't think it was low enough to cause a problem like that though.
Lead Driver
Joined: Mar 2006
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From: western SD
The voltage regulator is on the back side of the alt. It is that piece where the wires plug into on the top. It is easy to change just 2 or 3 bolts. You don't even have to split the alt.
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Lead Driver
Joined: Mar 2006
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From: western SD
That alt is different from mine. That one will need to be split to get to the voltage reg. You can see it, the grey plastic part with, the green dot, at the bottom of the alt. On mine it is on the outside of the case in the same location, and it covers the "jail bars" on your alt.
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Ok so after some investigating, realized it was a dual setup. Pulled both alternators out and had them tested by a reliable alternator shop. Both tested perfectly. Put the back in and still showing 16 volts on the ambulance voltage gauge. Multimetered the batteries and one battery is showing 12.85 and other two are showing 13.8 while running on a cold start. Not sure where to go from here now. Still have a steady battery light illuminated on the cluster. Also truck has no codes stored.
Lead Driver
Joined: Oct 2003
Posts: 8,476
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From: Madison, WI
If those voltage readings on the batteries were right after starting, disregard them. The glow plugs were probably still running. Wait until the glow plugs cycle off (up to two minutes) and measure again.
Where are the three batteries? Is there an isolator relay in place somewhere? Some of the other diesel forum sites have sections dedicated to the PSD E-series; there might be more insight/info there, since the ambulance package electrical mojo is more common to them.
Where are the three batteries? Is there an isolator relay in place somewhere? Some of the other diesel forum sites have sections dedicated to the PSD E-series; there might be more insight/info there, since the ambulance package electrical mojo is more common to them.