Another wiring question 68 c10

[68is4me]

68 c10

Ok Running a 12si alt 90amp, everything is wired correctly. Have an #8 wire from alt to distribution block on drivers side fender with all the correct splices coming off that block.

I am running air bag suspension with 40amp max draw on the compressors. Right now the compressors are drawing right off the battery with a #4 wire. The compressor will run while the engine is not running with key on and this is how I want to keep it.

The problem with the engine running and the compressor running the fusible link from the pass junction block to the battery gets very warm. It has not been any problems yet but might be in the future.

So the question is can I upgrade the wire coming off the driver side junction block, going over to the pass block with an #8 wire and also upgrade the fusible link to a #12? Would this have any affect on the amp gauge?

[ray_mcavoy]

Yes, you can upgrade that wire & fusible link. But as you suspected, it will affect the ammeter.

That wire serves as the external shunt for the battery gauge (ammeter). Since the heavier gauge wire has less resistance per foot, it will also have less voltage drop (for a given amount of current) than the stock wire. So it will reduce the sensitivity of the meter. Probably not a big deal but that does tend to reduce it's usefulness.

[68is4me]

Thanks ray. That is what I kind of figured. I do like the amp gauge so I will see how much it affects it by updating the wiring. I guess I would rather have stronger, and safer wiring over the use of the amp gauge.

[VetteVet]

You can solve your problem by tapping off the starter solenoid with the large battery cable and running 2 4 ga wires to your compressor relays with 2 inline 70 amp fuses. Then you don't have to change the wiring for the 12 gauge with the 16 gauge fusible link from the battery positive to the right fender junction.


Here's 2 diagrams of the wiring with the exception they show the compressors feeding off the positive battery terminal instead of the solenoid. Both of these diagrams feed off the battery and should not draw through the 16 gauge fusible link.

The battery will still charge OK with the 12 gauge wire from the alternator battery junction back to the battery through the 12 gauge wire, and you will get battery compressor feed.

[68is4me]

That is how I have them currently wired, hooked directly to the battery. But only used 1 wire with a 70amp breaker by the battery with a disconnect. I might have even used 2 gauge it has been a couple of years ago, but I know the wire is big enough for the load.

What advantage would I get over hooking to the starter solenoid vs hooking to the battery? The starter wire is just hooked directly to the battery.

[VetteVet]

Originally Posted by 68is4me

That is how I have them currently wired, hooked directly to the battery. But only used 1 wire with a 70amp breaker by the battery with a disconnect. I might have even used 2 gauge it has been a couple of years ago, but I know the wire is big enough for the load.

What advantage would I get over hooking to the starter solenoid vs hooking to the battery? The starter wire is just hooked directly to the battery.

It is the same but I thought it would be easier to connect at the starter. You just can't come off the fender junction using the fusible link as the supply for the compressors.

[68is4me]

That's what I thought. I don't have anything running off the rt side junction block. So I will keep everything like it is and replace the fusible link with a new one maybe it is just getting to old as it looks like the original.

Thanks Vette

[VetteVet]

keep me posted.