Rangeroverfamily said:

Good evening,
I recently changed my alternator and this morning the check engine light came on. I went to 3 auto shops to get it read (all said the truck was registered but not reading); finally got it diagnosed as a p1607


P1607 Malfunction Indicator Lamp Short Circuit Fault

May someone help me to understand what this means...
Do I have a short in my diagnostic adapter under the glove box?

Thanks in advance

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Datatek said:

Did you fit the correct alternator? that fault could be anything as it doesn't say which indicator lamp, but guessing it could be the charge lamp as that is activated via the BECM so if the alternator spec is wrong could be that, or the D+ wire is shorting somewhere.

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Saint.V8 said:

Malfunction Indicator Lamp (MIL) is usually the check engine light I think.....

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Rangeroverfamily said:

I believe it's the proper alternator, I checked the spec and it was an exact fit.
The brown wire on the alternator is alil frayed and crackling..
Also a few of my relays seem to be turning brown on the 87 & 1 prongs.


Do you know of any test I can do to see which light?

Just fyi...
On start up it, the check engine light doesnt come right on; It flickers as if its checking the cycles, then it stays solid.

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Rangeroverfamily said:

Worldwide Alternator Part: 13434
Alternator Case Type: Cast
Alternator Finish:*Same as OEM
Amperage Rating: 120 amps
Fan Included: Yes
Fan Type: Internal Fan
Internal Regulator: Yes
Lester Number: 13726
Pulley Diameter: 52 mm
Pulley Grooves: 7
Pulley Included: Yes
Pulley Type: Serpentine
Regulator Included: Yes
Regulator Plug Clocking: 09:00
Regulator Type: Internal Regulator*Voltage: 12 v

I think I narrowed it to the alternator I purchased from advanced auto parts ($185-local auto store)*

Please correct me if im wrong..*
I read somewhere that LR require 13.6 or better. I believe this alternator only*puts out 12.5 if that.*

I guess I have to spend alil more and get 1 from Atlantic British. They have the GEMS alt for $399.

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Datatek said:

Alternator output for the P38 is normally 14.2 volts, with a sealed maintenance free battery up to 14.8 volts is OK. Less than 13.8 volts is no good at all. It is possible to change the regulator, might be cheaper than your $399 Gems alternator.

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Datatek said:

Did you fit the correct alternator? that fault could be anything as it doesn't say which indicator lamp, but guessing it could be the charge lamp as that is activated via the BECM so if the alternator spec is wrong could be that, or the D+ wire is shorting somewhere.
Alternator output for the P38 is normally 14.2 volts, with a sealed maintenance free battery up to 14.8 volts is OK. Less than 13.8 volts is no good at all. It is possible to change the regulator, might be cheaper than your $399 Gems alternator.

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Rangeroverfamily said:

After re-reading this thread, It's funny how you started and ended with just the right answers!

Thank you. It was the alternator

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