400i

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thunder20
Posts: 6
Joined: Tue Sep 03, 2002 8:50 pm

400i

Post by thunder20 »

I just found out I have some type of short called a dead short which Iam told it means i have power coming from both sides of my battery cables. I took it in check because of battery drain after being park for two days . Has anyone ever have this problem if so hat should I check for first .
zac
Posts: 330
Joined: Tue Sep 10, 2002 1:01 pm
Location: San Diego North County

Post by zac »

Here is my best method for chasing shorts without taking all day. first get a good DVOM( volt ohm meter) and set it in amps mode. dissconnect the negative battery terminal and hook one side of the meter to the negative post and hook the other to the cable. what ever amps you are reading is your draw. on most early computer controlled cars 15-30 miliamps is all you want but it can be slightly higher on some more modern cars with several computers and duedads. after you have a good reading pull each fuse one by one until the draw goes away or reduces significantly. once you have found the circuit the problem is on then start checking individual components. the common cause would be an alternator diode malfunction or a interior light switch staying on but just about anything is possible. A lot of the old guys actually prefer the test light method where in place of the DVOM you hook a test light and pull fuses until the light goes dim or out. On big draws the test light method is fine but on smaller more illusive problems you really need a good meter.

anyways hope that helps and good luck

Zac
400iman
Posts: 38
Joined: Mon Sep 16, 2002 2:54 pm
Location: Arizona USA

400i short

Post by 400iman »

I had this happen on an old Ford truck. I used the method Zac stated and it turned out to be the voltage regulator (it was drawing about 2 amps!), which would correspond to the diode(s) on an internally regulated alternator. Unfortunately, the 400i has 2 alternators, so it will take a little more checking. Good luck, and let us know what you find in case mine develops the same problem.
thunder20
Posts: 6
Joined: Tue Sep 03, 2002 8:50 pm

Post by thunder20 »

I ave a msd 6a and I want to modify to just use one alternator. Is this possible are fisable. I know I would have to buy a new alternator.
zac
Posts: 330
Joined: Tue Sep 10, 2002 1:01 pm
Location: San Diego North County

Post by zac »

It is not only feasible but reccomended there are tons of companys out there that make internally regulated 130A alternators that only need a switch ignition wire and a straight hot wire from the Bat no muss no fuss and no voltage regulator. not only that but they make clean power, that is a constant voltage not fluctuating depending on revs and they don't need to be revved to 1500RPM before they start charging. That would be the first thing I would do on my USA 365 if I wasn't so hung up on correctness.
Zac
tyang

Post by tyang »

These guys sell an alternator that will work:
http://www.powermastermotorsports.com/
They have a FAQ that will help. Their alternators require to be spun up to at least 1500 rpm to excite (start charging), but I think Ferraris have trouble keeping it below 1500rpm!

Check JC whitney as well. They have an an alternator that "self excites" which begins charging once the alternator starts turning.

Something to consider, however, is which alternator you plan to replace. If you mount the new alternator in the "backwards" position, make sure the cooling fins on the pulley are pitched in the right direction. Without good cooling, alternators will burn out. A good alternator shop should be able to supply you with the right pitch on the fan for your particular application.

Tom
thunder20
Posts: 6
Joined: Tue Sep 03, 2002 8:50 pm

Post by thunder20 »

I was noticing when driving on the freeway my oil temp was very hot , almost one notch from the end but when got off the freeway it went back to normal, which is in the middle of the gauge. IS this normal. sorry I dont have the numbers the automoblie is still at the shop and I cannot remember what the numbers are the gauge Thanks
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