Tdi voltages: 13.5 at the fuse?

[langy]

Howdy all:
For Tdi owners: I always thought Tdi's were regulated to 13.5v, until the other day when I had a unrelated wiring problem to sort out. The alternator is pumping out 14.2 on its side ( LR standard apparantly) but at the 100a fuse connector there is only 13.5.( Terminals clean and tight) Which for a 2 foot piece of thick copper wire is a bit weird. How do other tdi owners fare?

Langy

[stevo]

Hi,what is the voltage at the battery I have worked on toyota's that put
out over 14 volts at the alternator but at the battery under 13 volts due
to resistance at plugs also you can have a voltage drop at tne battery clamp.

You can find the source by using a digital multimeter leave the neg terminal of the meter connected to the neg post ,using the positive
lead of the meter work your way around the circuit start at the battery post then the clamp and follow the circuit checking all joints for any
change in voltage.

You can expect a very small loss over the length of the circuit,cleaning
any corrosion off suspect joints may help

[langy]

Yes, me and my dependable 'meter are way ahead of you: I've measured voltage at one end of the cable(which has no in line connectors I know of), and then on the other end. I come up with 0.7v drop over 60cm. I was wondering what other Tdi disco owners get at each end. From there to the battery drops 0.01, which is normal.

Langy

[disconut]

Do you have any sign of green or black discolouration at either end of the cable? Depending on the age of the car you may have moisture ingress causing hidden corrosion beneath the insulation and creating a high resistance. Remove one end of the cable and test the cable resistance. It should be near zero ohms. Be sure to zero your meter first to get an accurate check.
Cheers.

[drivesafe]

Hi langy, when you measured the cable, did you have anything running, air con, headlights even the fuel pump, if running, can cause a voltage drop but 0.7 does seem a tad to much but again if you had a number of things running or if you had just started the vehicle then the battery itself will cause a voltage drop and it can be much greater if the battery is low and / or in need of maintenance or replacing.

Cheers.