Interlock Blues

I got into trouble a few years ago and now have to have an interlock device in my truck to drive. So yesterday morning I went in to get it calibrated and mentioned that the device had been acting funny, reseting itself at random times and what not, so they made an adjustment to the device to change how much it draws (they made it less). So I was driving around and my truck ended up dying on a busy highway during rush hour and low and behold It isnt charging.



the interlock shop says that they didn’t touch the charging system so it’s not thier fault. so I’m stuck changing the alternator. Just seems fishy that it happened so quickly. Any Thoughts or ideas on what happened? Thanks

If my memory serves, they haven’t made the b2500 for some years now. That would make your truck definitely not late model. Things break on old vehicles. It would be pretty tough to mess up the charging system by adjustng the interlock device, but at that truck’s age it would be very likely that the alternator died from simple old age.

Change the alternator. Accept it as a small cost of operating an older vehicle. Check the battery while you’re at it. That could be part of the problem too.

I agree. As far as I know these things just wire into the starting system, basically in the same way as the neutral safety switch or the clutch switch. (One of the problems with the older ones was that if you had a manual transmission, you could just roll start it).

So it’s almost certainly unrelated. You might still need to talk to the shop before you change the alternator, though, since disconnecting the battery might set off a tamper detection code. I used to work at a shop where for whatever reason we got a lot of cars with these and there was a whole song-and-dance we had to go through to work on (or even move) them without getting the drivers in trouble.

thanks I went ahead and changed it- the truck is 10 years old so I guess it just went out. I just wasn’t sure since it all happened so quickly. $150- 3 hours out of my day- not the worst thing ever, but still something I’d rather happen on a monday than a friday.

BTW- you can still roll start the truck- it figures it out after about 5 minutes usually though and starts screaming

Um, can I assume from this that you’ve had occasion to try to bypass the interlock system? And the reason for doing so would be…?