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Skiyup
12-11-2017, 03:14 AM
I changed the alternator within the last month after checking it out. It had gone bad. Everything was fine but recently I have been getting pulsing headlights and when I turn on the fan it pulses, plus the engine has started the same problem. This week I made a short trip and the van would not shift out of low. From one or two posts I have read it seems there may be a relation. I am going after the Y cable first. Any additional suggestions. 2006 2500 450k miles, Have an icarsoft2 reader but it seems to be a little sketchy. Possibly related due to voltage/electrical snafu. thanks, Skip

Eric Experience
12-11-2017, 03:58 AM
Skip.
To damage an alternator you may have excessive current flowing, now its pulsing like a short some where, if the short is being fed by a thermal overload or high current cct breaker you would get that effect. You do not need any fancy test gear just logic and a multi meter. Measure the voltage on the 4 or 5 main supply ccts coming out of the battery terminals to narrow down the culprit. Eric.

Midwestdrifter
12-11-2017, 04:42 AM
You may have a crap alternator, or another wiring issue.

T1N vans do not have the infamous "y cable" that NCV3s have. Your problem is likely related to the engine/battery ground straps, the alternator itself, or the power distribution block on the battery positive terminal.

If you get out a voltage meter, you can start by checking the voltage at the alternator, then work your way to the battery. Measure the voltage across the two ground straps, etc.

Feel the various wires/cables. They should not be more than warm to the touch. If they are hot (uncomfortable to touch for more than a second) then you have high resistance connections somewhere.

T1Ns should have a running voltage of around 13.8-14.1V and it should be stable. Variance at idle should be less than 0.1V over a period of about 10 seconds.

Skiyup
12-12-2017, 03:45 AM
Have set aside tomorrow to attack the problem. Does anyone think that this could tie in to the transmission not shifting out of low? thanks in advance

Midwestdrifter
12-12-2017, 04:11 AM
Have set aside tomorrow to attack the problem. Does anyone think that this could tie in to the transmission not shifting out of low? thanks in advance

It is very possible. Sprinters are sensitive to proper operating voltage, and pulsing lights is definitely not proper!

What you are describing is probably transmission limp home mode. You can scan the transmission with a sprinter compatible scanner for codes. Personally I would get your voltage issue sorted first, before you dive into the trans, as you may get both birds with one stone.

Skiyup
12-12-2017, 04:50 AM
It is very possible. Sprinters are sensitive to proper operating voltage, and pulsing lights is definitely not proper!

What you are describing is probably transmission limp home mode. You can scan the transmission with a sprinter compatible scanner for codes. Personally I would get your voltage issue sorted first, before you dive into the trans, as you may get both birds with one stone.

Thanks and I will start at the meter. Strangely I am having problems now with my scanner.

Skiyup
12-14-2017, 03:55 PM
Thanks and I will start at the meter. Strangely I am having problems now with my scanner.

New symptom, the small connector directly behind the turbo is cycling up and down intermittently.