Voltage regulator location?

[cumminsfreak86]

I have read a lot of post trying to find the answer to this but cant seem to find the exact answer I'm looking for.

My truck has a mfg date of 04-91 and my dads has a mfg date of 12-91. My truck has an external voltage regulator and his does not seem to have this external regulator (or we just can't find it). I've heard of a stock computer regulator being in these trucks.

Was there a cutoff date when dodge switch from external to internal regulators in the 1991-92 model years?

Could I possibly be double regulating?

Also, is this stock regulator also known as an internal regulator?

If he should have the regulator, where could it be other that the firewall?

Both of our trucks are intercooled.

Thanks in advance,

Chris

[Mark Nixon]

4-91= 1991 model year (Referred to as "1991.5, which is after 1-1-1991, by many).
12-91= 1992 model year.

1991 and 1992 are both, technically "extrnally" regulated, in that the voltage regulator circuit, or system, is not a directly incorporated part of the alternator, it's a separate module.

The voltage regulator on pre-'92 model year CUMMINS trucks (gassers are different) is on the firewall, directly behind, and slightly above, the ngine.
On '92 Cummins-powered trucks the voltage regulator is integrated into the ECM located behind the battery, inside the fender.

The "1991.5" trucks also used a fender-mounted ECM, but THEY DO NOT INCORPORATE THE VOLTAGE REGULATOR SYSTEM INTO THIS YEAR.


Mark.

[cougar]

The "1991.5" trucks also used a fender-mounted ECM, but THEY DO NOT INCORPORATE THE VOLTAGE REGULATOR SYSTEM INTO THIS YEAR.


Mark.

Mark, did you ever notice if this was a serial number thing?
1= US
3= Mexico

[cumminsfreak86]

Thank you for replying. That helped alot.

[Mark Nixon]

Mark, did you ever notice if this was a serial number thing?
1= US
3= Mexico

Never looked at it from that angle, all I ever look at is if it is/was Intercooled or non-intercooled, and I look for the regulator or for holes where it was mounted to determine if it may have been a '91 or earlier.

I've never found a '91 DIESEL truck, Intercooled or Non, that DIDN'T have the external regulator.

Mark.