What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

1990 K5 Alt Charginh

I've read SOME stories of people not using a resistor of any type and still getting charge.

Since you have a separate voltmeter, with the cluster removed, check the voltage coming into the instrument cluster with the truck running. Due to the age of the wiring, the distance, and number of connections in the wiring from the alternator to the cluster, voltage can very often vary. Yours is off too much IMO, but that may be a result of a bad connection.

You can always check voltage at the fuse panel and the junction block in the engine bay too if your voltage looks off at the cluster, see if you find something obviously bad that is causing voltage issues.

Those clips appear to be stainless steel, I've not seen any corroded yet, but I'd be looking for a bad contact.
 
I think I'd be checking connections on the firewall where all the wires come together and anywhere else. Sounds like a bad connection somewhere.

I don't think it needs a resistor with a gauge, I know I never installed one when I switched to serpentine setup on my '86, of course it already had a gauge cluster though, been awhile since I tinkered with that stuff though.
 
So the alt charging low voltage gauge has been resolved. The metal tab had a loose connection, when I pushed the gauge in the tab pooped out of the cluster.

I did not see a alt indicator light. In my opinion the compartment is there and there is a light, however nothing is printed on the thin plastic piece. See attached photos and this is for a 1990.

For grins I took apart my 1988 to verify and the cluster is a bit different and not compartment or light in that position, see photos

20150206_201059.jpg

20150206_202145.jpg

20150206_203620.jpg
 
These don't have the indicator lights for charging, only the check engine light when you first turn the key on.

And since you've got it apart, you really should remove what gauges you can and paint the inside of that cluster with some silver or that spray can chrome. It's not really chrome, just a really shiny silver. It seriously helps with a dim dashlight problem these tend to have.

I did it to my '86 dually I had a few years back and it was crazy the amount of light came from doing that one little thing

I really need to get around to doing it to the burb now.
 
Now you are going to make me take my spare one apart. That light there can't do anything where it is to help the cluster illumination, right? That's odd, I'm certain mine has the little lens thing like the "brake" or "check engine" lights do, yours looks like its part of the black piece?

Did you try plugging the cluster in with the black piece removed (making sure bulb is good) and turning key on? GM would never have installed a bulb if it didn't do *something*.
 
dyeager535 said:
Now you are going to make me take my spare one apart. That light there can't do anything where it is to help the cluster illumination, right? That's odd, I'm certain mine has the little lens thing like the "brake" or "check engine" lights do, yours looks like its part of the black piece?

Did you try plugging the cluster in with the black piece removed (making sure bulb is good) and turning key on? GM would never have installed a bulb if it didn't do *something*.
Click to expand...

I agree with you that its there but does nothing. It does come on with the key on. The only possibility would be if someone over the years put a different thin plastic cover over the gauges...
 
I just looked at my '91 wiring manual, and I see nothing referencing ANY charge indicator used in those three positions (or anywhere). The manual also doesn't say where in the cluster each indicator goes. For all I know the specific diesel lights ended up over there by then or something.

Oddly, I see nothing on the alternator/charge system wiring showing any sort of resistor in the diagram, and a mention of an internal wire in the alternator to start charging. I'd be hard pressed to believe a CS130 (or 144) isn't exactly like another in terms of wiring, but could be wrong. That brings into question the resistance belief that is prevalent.

I'll have to check my clusters, I've been wrong before but I swear that one of them has a blue battery indicator in that position. I doubt yours was swapped out, as my friend with a 1990 Suburban does not seem to have an indicator there either.
 
dyeager535 said:
I just looked at my '91 wiring manual, and I see nothing referencing ANY charge indicator used in those three positions (or anywhere). The manual also doesn't say where in the cluster each indicator goes. For all I know the specific diesel lights ended up over there by then or something.

Oddly, I see nothing on the alternator/charge system wiring showing any sort of resistor in the diagram, and a mention of an internal wire in the alternator to start charging. I'd be hard pressed to believe a CS130 (or 144) isn't exactly like another in terms of wiring, but could be wrong. That brings into question the resistance belief that is prevalent.

I'll have to check my clusters, I've been wrong before but I swear that one of them has a blue battery indicator in that position. I doubt yours was swapped out, as my friend with a 1990 Suburban does not seem to have an indicator there either.
Click to expand...

Periodicly I keep blowing the 5amp gauge fuse. Can you look at the wiring manual and let me know where the gauge wire goes and where I should be looking....

thanks
 
Hmm. I can try and look it up tonight.

I would assume it just goes from fuse panel to the IP connector...it's the 12V source that feeds all the gauges/lights, right?
 
I don't quite believe the wiring manual specified fuse, I'd want to check an owners manual, or with some others who have '90-91's and see what their truck has, however the 1991 R/V wiring manual says the fuse should be 20A (that seems like too much to me). It is labeled "GAGE/IDLE" on the fuse panel according to this.

This circuit powers the cluster (at pin 4 on the cluster connector, pnk/blk wire) and the buzzer at the convenience center, which is tied into the seat belt indicator light.
 
4xcrazy said:
These don't have the indicator lights for charging, only the check engine light when you first turn the key on.
Click to expand...

Now we have to figure this out lol.

Both 90-91 clusters I have on the shelf have the charge indicator light in the former clock position, and I'm 99% sure the one in my truck now also has it. Those filters on them are really good though, even with a flashlight from the front on the filter I can't make it out, but with a light from behind, it's clear. It is red.

One of the clusters still had the bulb in that position (probably the last one I pulled from a running truck) so I'm certain it was used.

Does anyone know when/if a 100% changeover to the CS series alternators took place on the R/V series? The only thing I can think of is that the SI-series trucks didn't get the charge indicator light, and the CS ones did. I don't recall seeing a difference listed in the 1991 electrical manual for alternator type.
 
Well they would probably have the light if it was a basic light style dash, even for the oil pressure, instead of the gauge it was a low oil pressure light. Not sure why it would still be hooked up and working if they equipped them with full gauges though. I thought that was a clock position in there, if optioned, so it would use that bulb to illuminate the clock from behind when turned on.
 
No, '90-91 clusters never got a clock there, housing was not cast for it. Picture is above.

All I can come up with is that the CS and SI-series got different clusters. Still doesn't make sense to me, since the previous SI-equipped trucks (with gauges) didn't have a charge indicator I am aware of, at least from '81-up...only positions left when fully optioned were the four slots below the speedometer and fuel/tach, those were brake, seat belt, 4WD, and check engine or choke.

Light bulb may have been a cheap alternative to resistance wire to prevent backfeeding the alternator when the rig was turned off. But I am unaware of resistance wire, although my Dad is pretty sure his setup (either 70's or 80's pre-efi) used resistance wire on the alternator circuit.
 
dyeager535 said:
I don't quite believe the wiring manual specified fuse, I'd want to check an owners manual, or with some others who have '90-91's and see what their truck has, however the 1991 R/V wiring manual says the fuse should be 20A (that seems like too much to me). It is labeled "GAGE/IDLE" on the fuse panel according to this.

This circuit powers the cluster (at pin 4 on the cluster connector, pnk/blk wire) and the buzzer at the convenience center, which is tied into the seat belt indicator light.
Click to expand...

Trying to circle back to this, It is a 5amp fuse and it says instr/lps. What I have noticed is that I can put new fuse in pull the head light switch out and it is ok. I can dim it left and right ok, but when I make it far enough to just about turn on the dome light (that notch in the switch) that is when it pops the fuse...It is repeatable....Any help as to where I should be looking to track this down. My first thought is possibly a faulty head light switch??
 
If you quickly jump the dimmer to dome, does it still pop?

I'd check to see if anyone has an owners manual for that vintage. It SHOULD show the fuse rating for each slot. If not I can check the 1991 service manual, perhaps the 20A I saw in the wiring diagram is confirmed elsewhere. Would hate to put a 20A fuse in there if there is a real problem.
 
No we are not talking gauge idle fuse anymore, It is the instr lps fuse shown in above pic 5amp.
 
You must log in or register to reply here.

Latest Posts

Top Bottom