# 87 d21 volt reg



## boing757 (Dec 12, 2007)

I've been having trouble with my charging system.It charges at idle but doesn't at load. I put in a new alt and now believe it to be the voltage regulator.The problem is I looked around and cannot find anything that resebles a regulator.It does not have an internal regulator.Also I have found two different ones on line for $10 &$62.What would be the difference and where is the regulator ,Bob


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## SPEEDO (Jun 9, 2003)

The volt reg is internal... Nissan hasnt used a external since the 70's


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## 88pathoffroad (Jun 6, 2004)

Ditto. The alternator is internally regulated.


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## smj999smj (Jan 1, 2006)

Don't confuse the "voltage regulator" available for the instrument cluster for the charging system alternator's regulator, which, as mentioned, is internal of the alternator.


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## SPEEDO (Jun 9, 2003)

good point^ there is a voltage regulator for the gauges behind the
speedo cluster... little silver or black box


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## gogiburn (Dec 17, 2007)

Hey guys,my 90 doesn't have the boX?for the gauges????


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## 88pathoffroad (Jun 6, 2004)

The voltage regulator for the gauges is ONLY for the fuel and temp gauges. It is on top of the back side of the cluster with three wires(yellow, blue and black) going from it to the back side of the cluster.


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## gogiburn (Dec 17, 2007)

*VR for gauges*

Sorry,I have the gauges out and in front of me.I pulled them because mine were not working and some one sent me pics of it and that that was my problem.When I took the gauges out there was NO BOX and NO THREE WIRES? Just the stamped wiring diagram of copper for all the different things.I wonder if the accessory relay over the fuse box is what runs the gauges on my 90?


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## smj999smj (Jan 1, 2006)

gogiburn said:


> Sorry,I have the gauges out and in front of me.I pulled them because mine were not working and some one sent me pics of it and that that was my problem.When I took the gauges out there was NO BOX and NO THREE WIRES? Just the stamped wiring diagram of copper for all the different things.I wonder if the accessory relay over the fuse box is what runs the gauges on my 90?


In later models, the I/P voltage regulator was incorporated into the fuel gauge assy. and non-serviceable.


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## gogiburn (Dec 17, 2007)

*VR Gauge*

OK,what year starts the later model? I have both 
86 1/2 and 90 gauges and neither has the box????


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## 88pathoffroad (Jun 6, 2004)

My '88 Pathy has one and so did the '91 gauge cluster I have. Sorry for the misinformation, I was under the impression that they used the same setup in the D21 trucks and WD21 Pathys.


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## gogiburn (Dec 17, 2007)

What do you mean by later years??????????????????????????????????????


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## smj999smj (Jan 1, 2006)

From what I see, 86-1/2 had two differant setups per TSB #TS86-127; "with Sub-gauge" used the voltage regulator bolted on the back of the cluster and "with Main Gauge only" did not have it, at least according to the pics in the bulletin. My guess these would translate to "SE" vs. "XE/E" model gauge clusters, as the part numbers for the fuel gauges are designated that way. The electrical diagrams for the 90 models show the dash voltage regulator as being integral of the fuel guage itself.


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