'69 Rally Cluster Question

gtodrive · Guru

'69 Rally Cluster Question

4SPEED427 · A Poncho Legend!

Hopefully Mark or Todd will see this. They both have done it I believe.

My experience with the 65-66 cluster won't help since they already have ammeters in those cars before the cluster swap.

Canadian Poncho · A Poncho Legend!

I did not use the ammeter gauge when I installed the rally cluster in my car.

seventy2plus2 · Canadian Poncho Superstar!

I've never quite figured out the ammeter wiring, even though I have a couple diagrams. I would think it's wired the same as a 67 B body as they had an ammeter guage on all cars.

Pontiacanada · A Poncho Legend!

I've heard that an ammeter gauge isn't that useful. Is that true?

4SPEED427 · A Poncho Legend!

Yes, a voltmeter is far superior, at least my two cent opinion says.

Canadian Poncho · A Poncho Legend!

Here's a photo of the cluster I installed in my Laurentian.

marxjunk · Veteran Member

Todd, whats up with that tach..never saw that before..

Canadian Poncho · A Poncho Legend!

I modified a repro tach from a 69 Nova to fit where the clock used to be.

gtodrive · Guru

Nailhead wrote:
......amp meters are not that great, a Volt meter is much better. The amp meter requiers heavy guage wires ( 8-10 ) , gives off more heat in the circuit and is more prone to causing a short thus a fire. The guage needs to match the gen /alt , meaning if you have a 60 amp alt then the guage should be at least 60 amp. If you swap out the alt to a 100 amp and the guage is less then it will overheat and poof ! Amp guage didn't measure draw either. I know it would be nice to see the guage working in that cluster but I would not trust it.

I guess at this point I will forget trying to use the stock ammeter. I don't have time for a volt meter conversion at this point (car show committment the first part of May) so I will wait and have that done next year. Now if we still have snow in May I will regret not doing it!

seventy2plus2 · Canadian Poncho Superstar!

gtodrive wrote:
Nailhead wrote:
......amp meters are not that great, a Volt meter is much better. The amp meter requiers heavy guage wires ( 8-10 ) , gives off more heat in the circuit and is more prone to causing a short thus a fire. The guage needs to match the gen /alt , meaning if you have a 60 amp alt then the guage should be at least 60 amp. If you swap out the alt to a 100 amp and the guage is less then it will overheat and poof ! Amp guage didn't measure draw either. I know it would be nice to see the guage working in that cluster but I would not trust it.
I guess at this point I will forget trying to use the stock ammeter. I don't have time for a volt meter conversion at this point (car show committment the first part of May) so I will wait and have that done next year. Now if we still have snow in May I will regret not doing it!

Let me look into my info a bit further. I know my buddy Larry in Kansas did the conversion on his 70 2+2, and he sent me some info. I remember he said he went to the local shop and bought a cheap ammeter, and just wired the one in the ralley cluster the same way. He did not need the heavy guage wires suggested above. The alternator current is not flowing through the ammeter, the ammeter is just showing the potential differential between the alternator output and the battery.

65wagon · Poncho Master!

just my two cents, i unplug the factory amp wiring harness its live all the time, on 65s part is hooked into the starter circiut, i take the gauge apart and put the face plate on a gm voltage gauge, you get rid of the fire trap and get a working gauge out of the deal, i steal the votage gauges from 80s montes or trucks.

gtodrive · Guru

Nailhead wrote:
.....I was actually doing this the other day, so I was studying the amp guage hookup. I'm using a 56 Chrysler guage cluster in my 49 chev truck, olds wiring harness that had a idiot light only, and want to use a 100 amp one wire delco alt. Amp meters need a heavy full load from the battery and back to the alt, so it must be a 8-10 guage wire. Today's vehicles have lots of power accessories like a/c, windows, big stereos etc , so alot of power is needed to run them. A thin wire will get hot to a amp guage and can burn off, fall down under the dash and you have a live wire on the lose. The meter can also not take much load if the alt is putting out alot and the guage doesn't match the alt output thus another fire hazard. After reading alot on the net about the amp guages, I decided not to even try hook mine up, and it turns out the one wire alt will not work with a guage or idiot light anyway. Volt meter don't need the heavy wiring , can handle higher voltage and are much safer. And to think about it, how often do you see one of the amp guages actually working in a older vehicle ?

All these are good points and it seems the opinion is ammeters are bad. What I still question is a lot of 60's cars used them. I can't see how an ammeter wired in a fused circuit is bad. If cars were on fire back in the day because of these units were unsafe, I think the manufacturers would have done something? Obviously, I don't want a fire in my car so I am tentative about wiring it up at this point.

4SPEED427 · A Poncho Legend!

65wagon wrote:

just my two cents, i unplug the factory amp wiring harness its live all the time, on 65s part is hooked into the starter circiut, i take the gauge apart and put the face plate on a gm voltage gauge, you get rid of the fire trap and get a working gauge out of the deal, i steal the votage gauges from 80s montes or trucks.

Hmm, you've got me thinking about my 66 now

seventy2plus2 · Canadian Poncho Superstar!

Carl Stevenson wrote:
65wagon wrote:

just my two cents, i unplug the factory amp wiring harness its live all the time, on 65s part is hooked into the starter circiut, i take the gauge apart and put the face plate on a gm voltage gauge, you get rid of the fire trap and get a working gauge out of the deal, i steal the votage gauges from 80s montes or trucks.

Hmm, you've got me thinking about my 66 now

Carl, I was hoping you could check your 66, as I presume it has an ammeter and that you'd have a service manual with a wiring diagram. It would show the connections.

seventy2plus2 · Canadian Poncho Superstar!

I went through the info I had, but it just shows what pin goes to what on the back of the cluster. I then looked at my 70 Pontiac US service manual, as it contains some info.

Page 15-22 labelled "Fig 15-26 Pontiac Auxillary Gage Installation" shows the left side of the temp/battery guage pair (right side from back of guage) being wired to ignition power, and the right side of the battery guage wired "to battery terminal of generator".

Page 12-9 labelled "Fig 12-10 Pontiac Printed Circuit with Auxillary Gage" shows the 2 pertinent pins labelled "Ammeter-Bat" and "Ammeter-Alternator".

I have bought a number of these guage clusters, complete with wiring and have not seen any with anything close to 10 guage wiring in them. The alternator output is not travelling through these wires, the guage is simply showing the voltage potential difference between the alternator output and the battery.

If you have a 69 Pontiac US service manual I trust it would have similar drawings. The auxilliary guage package is not shown in the Canadian service manual.

4SPEED427 · A Poncho Legend!

seventy2plus2 wrote:

Carl Stevenson wrote:
Carl, I was hoping you could check your 66, as I presume it has an ammeter and that you'd have a service manual with a wiring diagram. It would show the connections.

I can check that. I do have the manual for the 66. Never knew I did, found it a few weeks ago one night after I asked someone here for help with a wiring diagram for it!

gtodrive · Guru

seventy2plus2 wrote:
I went through the info I had, but it just shows what pin goes to what on the back of the cluster.   I then looked at my 70 Pontiac US service manual, as it contains some info.
Page 15-22 labelled "Fig 15-26 Pontiac Auxillary Gage Installation" shows the left side of the temp/battery guage pair (right side from back of guage) being wired to ignition power, and the right side of the battery guage wired "to battery terminal of generator".
Page 12-9 labelled "Fig 12-10 Pontiac Printed Circuit with Auxillary Gage"   shows the 2 pertinent pins labelled "Ammeter-Bat" and "Ammeter-Alternator".
I have bought a number of these guage clusters, complete with wiring and have not seen any with anything close to 10 guage wiring in them.   The alternator output is not travelling through these wires, the guage is simply showing the voltage potential difference between the alternator output and the battery.
If you have a 69 Pontiac US service manual I trust it would have similar drawings.   The auxilliary guage package is not shown in the Canadian service manual.

This has been my thinking on the size of wire all along for this reason: My experience with the idiot light has been that with problems of undercharging it glows dim and with problems of overcharging it is bright. And wouldn't the idiot light have similar current running through its 20 gauge wire? I will see if I can get ahold of a '69 American service manual, however I would think the '70 would be the same for this set up. Clint, could you post a scan of the diagram? Thanks.

65wagon · Poncho Master!

Carl Stevenson wrote:
65wagon wrote:

just my two cents, i unplug the factory amp wiring harness its live all the time, on 65s part is hooked into the starter circiut, i take the gauge apart and put the face plate on a gm voltage gauge, you get rid of the fire trap and get a working gauge out of the deal, i steal the votage gauges from 80s montes or trucks.

Hmm, you've got me thinking about my 66 now

the only reason i brought it up was because i had a underdash fire in the wagon when i first got it, all the cars now have their amps converted

Beaumont4008 · Uber Guru

Interesting that the 69 full size had the Amp gauge and the 69 Beaumont did not. The 69 Beaumont rally gauge only had Fuel, temp and oil with only a GEN light. One of those wonder why things.

4SPEED427 · A Poncho Legend!

65wagon wrote:

the only reason i brought it up was because i had a underdash fire in the wagon when i first got it, all the cars now have their amps converted

I think I've heard enough. I need to get the wiring diagram out and disable the ammeter on my 66. I don't need a dash fire. It had a melted wire to the ignition switch when I got it. That's fixed now and I don't need a repeat.

seventy2plus2 · Canadian Poncho Superstar!

The drawings aren't wiring diagrams, they're just a drawn pictorial. However, I did have a couple under-dash harnesses for 1970 Ralley Guage clusters. Speedo connector Pin # 10 (Ammeter-Alternator) has a 16 guage tan wire that goes directly to a single pin on the firewall connector. Pin # 11 (Ammeter-Bat) has a 16 guage black wire that goes directly to a different single pin on the firewall connector. Neither of these wires stops inside the passenger compartment. However I don't know where they go on the engine compartment side.

I suspect the black wire continues on to the junction block near the battery. On my car, there is a fusible link from the battery + terminal to the junction block which is hidden behind the battery.

I suspect the tan wire goes to a switched side of the fuse block so it's disconnected when the key is turned off. I'd say the "ACC" terminal on the fuse block is a good place, as it's only on when the key is on.

gtodrive · Guru

So, with the 16 gauge wire being used, you are kind of confirming my theory that the ammeter gauge is a "glorified" idiot light...right?

seventy2plus2 · Canadian Poncho Superstar!

I'm going to check the wiring diagram in a buddies 67 Parisienne service manual to see how it's wired, but in the 3 underdash harnesses I have for Ralley Guages they are all the same (16 guage wire). To me, the 69/70 units aren't necessarily showing amps but showing which has a higher potential.

65wagon · Poncho Master!

Carl Stevenson wrote:
65wagon wrote:

the only reason i brought it up was because i had a underdash fire in the wagon when i first got it, all the cars now have their amps converted

so its rearmed ready for more, i carry a fire extiquisher, but the fire happened in the garage with the key off

I think I've heard enough. I need to get the wiring diagram out and disable the ammeter on my 66. I don't need a dash fire. It had a melted wire to the ignition switch when I got it. That's fixed now and I don't need a repeat.