Determining wire gauges in the FSM?

[Ronnie]

I'm in the planning stages of adding a relay to the headlight circuit of my Reatta to take some of the load off the headlight switch. Is there a way to find the size of the wires used by looking at the FSM? It would save me some time if I know the size of the wires before I start the job.

[2seater]

The wire gauge is listed right on the wiring diagrams, but it is metric, like .8(mm), but I don't remember if it is area or diameter, and it makes a difference. .8 sq.mm is about 18ga, and .8mm diameter is more like 20ga. I am pretty sure the terms are described in the FSM at the beginning of the section. I will look when I get a chance but a conversion chart would be very handy.

[Ronnie]

Thanks Hal. I wasn't looking for metric wire sizes. I'll take another look at the FSM and see what I can find out.

[2seater]

I found this on another GM forum, which sort of addresses the same question:

 

http://forums.trailvoy.com/archive/index.php/t-7526.html

[Ronnie]

Thanks! That's the information I was looking for. I wanted to make sure the relay socket and harness I ordered has large enough wire to carry the load of the headlights.

[2seater]

On 5/11/2017 at 3:18 PM, Ronnie said:

Thanks! That's the information I was looking for. I wanted to make sure the relay socket and harness I ordered has large enough wire to carry the load of the headlights.

 

I found it in the FSM so it isn't Chebbie info. :rolleyes:

 

[Ronnie]

Great minds must think alike. ::) When I saw your post I was in the process of grabbing a screen shot in the '89 FSM of the same chart to add to ROJ. Your photo must be from the 1990 FSM because the chart is on the opposite side of the page.

[2seater]

10-4, that's just what it .is. It confirms the other information from the Trailblazer forum but reads better, but not of tutorial quality :)  A lot of wiring is pretty light gauge and can stand an upgrade. Even a stock headlight will be brighter with the upgrade.

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[Ronnie]

I'm surprised that most of the wiring that supplies power, like the orange wires, is only .8mm or 18 gauge. The relay socket harness that I bought has 14 gauge wires so it should handle the load just fine. For cars that were supposed to be top of the line, and so expensive for their time, they sure do seem to use a lot of light duty wire.

[DAVES89]

Kendall was surprised that a lot of connections aren't as weatherproof as they could have been. So it is not just the gauge of the wire. For as "electrical" as these cars are they could have done a bit better in these areas.

However I still like my car!