Anyone had a PDM go out?

Rex Winters

Rex Winters

Member
So about 11 months ago I replaced my WORKING ehc to a PDM, so I wouldnt be stranded somewhere in the middle of the night. It worked great until about 2 weeks ago, then the positive terminal of my battery melted (yes, I used the spacer to align the cable right), with no other signs. The battery was about 8 mnths old, and still was showing 12.7v on a multitester. The bike would get power, but would not even attempt to crank. Not even a clicking noise, but lights would come on, horn worked, turn signals, etc. Since I am in Tampa for another month, and have limited tools, I bit the bullet and took the bike to Big Dogs and Hogs. They told me the PDM/HCI was bad and are sending it to Big Dog to analyze. Anyone else swap for the PDM and have issues? Hopefully the $800 and time spent to replace the system was worth it. If I have to spend another $800, I will be pissed! It only lasted 11 months...
 
pknowles

pknowles

RETIRED
I know you said the wire was tight, but sounds like it wasn't getting a good connection to melt the post. We have a lot of that going on with some of our marine equipment.
 
Nukeranger

Nukeranger

Nukeranger
pknowles said:
I know you said the wire was tight, but sounds like it wasn't getting a good connection to melt the post. We have a lot of that going on with some of our marine equipment.
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X2-Reading your post, I would also believe your post or wire terminal was not clean or did not have proper full connection causing a high resistance at the battery terminal that melted. You will get good voltage but not the current flow needed to start your bike.
 
Rex Winters

Rex Winters

Member
I agree, it sounds like that, but my last battery showed a little bit of melt, so when I replaced it (8 mnths ago) I was extra careful to make sure. Now that the PDM went out it makes me wonder if that wasnt the cause of the battery problem...
I even traced all the wires to make sure no loose connections. I am baffled. I have to believe the HCI/PDM was bad and caused the battery problem.
 
07bigdog

07bigdog

07BIGDOG
I have one of the early PDM kits from Bigdog before they went out of business. Bought in 2010 and just installed this spring. Ignition module kicks off when start button pushed. Phoned Bigdog and faulty HCI and no warranty. Also didn't install horn relay kit that they sent me months later and bike shuts down when you press horn button. Bought a new style PDM but haven't installed yet. I added resistors and an LED bulb to the HCI and it is working that way. I have over $1500 in 2 PDM kits with brokeage and tax fees sent to Canada.
 
Diesel Dan

Diesel Dan

Well-Known Member
ask Brother Raywood about his opinon on the Big Dog PDM...........broke down on him once and left him totally screwed......now his bikes been down for about 4 or 5 months with another breakdown.......
 
bearman

bearman

Active Member
Rex Winters said:
......Now that the PDM went out it makes me wonder if that wasnt the cause of the battery problem.... I have to believe the HCI/PDM was bad and caused the battery problem.
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I can't believe that the PDM or wire plus or the old stock EHC can cause anything else to melt a battery terminal.

The only wires on the whole scooter that can carry enough juice to melt the battery terminal is the starter wires. So either you have a dead short to ground on the positive wire or the starter is bad.

If the starter is bad there is a possibility it can draw enough juice to melt the battery terminal.

But more likely the starter didn't disengage after cranking. If this happens the starter turns into a generator with no regulator or fuse so there's no telling how much voltage and current that it will put out when you rev it up.

High voltage can kill a PDM, Wire Plus, an EHC or anything else electronic, although a fuse is supposed to protect it.

Just my theory but I would check the starter.
 
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