the mechanic uses a volt meter I think, when the truck is started, it measures 14 and above, as soon as the idle goes to normal, about a minute, the battery measures 12 and below. We can hear a click in a little blue unit, there are two of them side by side near the driver fender when this unit clicks the battery does not charge. Both of these little relays are identical, we switch the wires from one to the other and it is no difference. ??
According to the million schematic I've seen, I have never seen a single relay in between the Charger and the battery. Battery and Alternator are directly connected, you can verify from Positive pole of the battery to the Alternator, you should see 0 ohm. It sounds to me that your mechanic may have a poor meter connection. When an alternator is running, it will never drop below 13.0V.
I have a doubt on how well your new is being called new? Is this a cheap rebuilt? Excuse me to say that.
R/C Foster:
My 1988 D21 pick-up has a big oval 2-wire plastic connector that plugs into the rear of the alternator. One wire connects the alternator S (sense) terminal through a fusible link to the positive terminal of the battery. The other wire connects the alternator L (lamp) terminal through the combination meter (charge warning lamp) and a fuse to the ignition switch.
If the L terminal connection is intermittent charging will be intermittent. The relay will click each time the connection opens or closes. If there are no other problems with the charging system the alternator warning light will also change state each time the connection opens or closes.
I know that my oval plug is bad because I can make the relay click by wiggling the plug while the engine is running. Voltage across the battery terminals drops from above 14 V to approx. 12 V (exact lower voltage depending on battery charge) whenever the relay clicks off.
I was unable to repair the plug by cleaning or bending the contacts or by applying Stabilant 22a. Replacement plugs are not available from auto parts stores or Nissan.
However, Northwest Regulator Supply/AmFor
Does anybody know another source of Nissan alternator connectors/repair leads? (Auto parts stores only seem to carry Ford and GM alternator connectors.)
Try using DeoxIT on the connections. Best stuff for improving connections. Mike
shaqtopz:
I thought that I was well-prepared because I had bought some Stabilant
22A a long time ago. It has helped me in the past but it did not do the trick this time.Does DeoxIT work better than Stabilant 22A? Maybe. However, given that a brand new connector without DeoxIT or Stabilant 22A generally works well for a long time I assume that the combination of a new connector and Stabilant 22A will work better than a combination of the old connector and DeoxIT.
Here somebody recommends a combination of DeoxIT and Stabilant 22A for use on computer connectors:
After my mechanic went thru the entire truck, connection by connection, put meters on every electrical connection he could find, tore out part of the dash, looking for something wrong. He finally decided it had to be the alternator or regulator inside the alternator, so he put everything back together, installed the 5th alternator, new by the way, it is now charging like it should. I think, but did not tell the mechanic, that it was a wire or ground that he moved or jiggled, not knowing that was the problem all the time. I don't think my problem ever was an alternator. Installing 5 rebuild/new units does not make sense........any thoughts on this? Thanks for all the help from the newsgroup..........
I would never mix one companies chemical with anothers without recommendations/approval from both companies. For computer connectors I use ONLY the Deoxit GOLD. Works like not other product on plated connections, especially gold surfaces. From what I have read and observed, the Gold stuff penetrates the gold surface and bonds with the base metal - and seals out oxygen from getting to the metal. Like stabilant it enhances the conductivity, unlike stabilant it dissolves oxidation and is ideal for moving or connectors under vibration. Stabilant is more of a grease and needs to be reapplied if it is removed or moved. Deoxit is more of a liquid film that moves and continually re-coats or reseals the surfaces. Stabilant is also a good lubricant. The deoxit site has a lot of tech infomation,
If you know the basic science, mixing shouldn't be a problem plus mixing could save you money(and energy). It depends on what it is you're trying to mix. Connectors that carries low current is not to be too much big deal, I agree Gold is the best conductance but it won't serve you best by having the best conductor in about 5% of the whole cable. Solid Housing is what I would look for in this case.
R/C Foster:
IMHO, the alternator plug, which is responsible for the S and L connections, is an electrical weak spot. The other two alternator connectors are much less likely to go bad because they are screwed on. In addition they would be easy to clean if that was necessary.
The charging system trouble shooting procedure in the Nissan repair manual is identical to the generic procedure that was recommended to me by the experienced alternator rebuilder who sold me my new (rebuilt) alternator. I followed this procedure exactly. However, it incorrectly identified the alternator as faulty because the procedure did not have a faulty alternator plug as a possible outcome.
The way to know for sure is to have the supposedly bad units bench-tested. Most auto parts stores have the required equipment and will test an alternator for you at no charge if you carry it in. Hiring a mechanic to repair your charging system may put you at a disadvantage because it may prevent you from having the old alternator tested. The mechanic will usually want to keep the old alternator in order to turn it in for a refund of the core charge that he had to pay for the new/rebuilt unit.
I am glad that I had both of my alternators tested, the new one before installation and the old one after removal. It greatly helped with troubleshooting.
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