Underhood Ammeter Bypass

[saylor]

stereos that ive ever messed with have a +12 for power and a +5 trigger to turn it on /off. I'd feed FUSED from battery direct IMO. same with the amp it should have a trigger wire or a way to put it inline with something that DOES have a trigger.

I did put a master toggle switch in tho, to kill the whole power to the whole radio + amps with 1 flip. just a SPST or whatever on/off toggle.

if you are putting any kind of bass in, you gonna want direct BATT power. When my sub hits the voltage meter drops

 

[JM_ART]

stereos that ive ever messed with have a +12 for power and a +5 trigger to turn it on /off. I'd feed FUSED from battery direct IMO. same with the amp it should have a trigger wire or a way to put it inline with something that DOES have a trigger.

I did put a master toggle switch in tho, to kill the whole power to the whole radio + amps with 1 flip. just a SPST or whatever on/off toggle.

if you are putting any kind of bass in, you gonna want direct BATT power. When my sub hits the voltage meter drops

I think I understand what you’re saying there. I’m not going to run anything very powerful, just enough to make things sound clear and crisp. Sound quality is more important than raw volume in my case, and I’m going to install a lot of Dynamat, or similar, wherever I can.

 

[Trace 300 Hurst]

I put a relay to my AC clutch. That's a fairly large and constant amp draw....the FSM calls for about 3-4 amps.

My install is virtually invisible to the OEM underhood appearance. I came off the alternator stud for current to the relay-to-clutch circuit (sneaking along with the horn wires), and covertly using the original clutch power wire inline with the pressure switch wiring to trigger the relay. This was a BIG improvement to my ammeter pegging the NEG side of the gauge.

 

[JM_ART]

I put a relay to my AC clutch. That's a fairly large and constant amp draw....the FSM calls for about 3-4 amps.

View attachment 399819

My install is virtually invisible to the OEM underhood appearance. I came off the alternator stud for current to the relay-to-clutch circuit (sneaking along with the horn wires), and covertly using the original clutch power wire inline with the pressure switch wiring to trigger the relay. This was a BIG improvement to my ammeter pegging the NEG side of the gauge.

View attachment 399817

Are you running the original compressor?

 

[Trace 300 Hurst]

Are you running the original compressor?

Yes.

 

[Ross Wooldridge]

Hey @Trace 300 Hurst - would you mind doing a more detailed "how to" article for us "like to follow detailed instructions" types?

Relays and isolated dedicated non-bulkhead routed power sources are something I intend on doing with both my cars.

Headlights (already done on both cars)
AC clutch
Ammeter reduction obtained by:
Total bulkhead main power bypass (already done on my Monaco as a factory police/fleet upgrade)

 

[rkrochen]

Looks like I am next on the list to do this upgrade. Having some issues with my charging system and now my gauges quit working. Need to dig into this but with my recent shoulder operation it may have to wait.

 

[Trace 300 Hurst]

just for flavor - the stock wiring is not 10AWG.
- saylor

I think we're talking about this 10AWG wire. Indeed, most other wires are 12 and 18. AND old!

 

[Trace 300 Hurst]

Hey @Trace 300 Hurst - would you mind doing a more detailed "how to" article for us "like to follow detailed instructions" types?

In fact, I have been intending [the best of intentions!] to do a How To for the clutch relay. The only picture I currently have is the one above, but it's the diagram that you need to figure out your own routing/location for the relay and wiring. I'll explain what I did in more detail.

So, you've built a fire under my arse and I'll do a writeup with a schematic diagram in the next few days.

 

[JM_ART]

Looks like I am next on the list to do this upgrade. Having some issues with my charging system and now my gauges quit working. Need to dig into this but with my recent shoulder operation it may have to wait.

Ow! Yeah, the shoulder may be an inhibitor, to say the least. Hope everything went well and best wishes for a speedy recovery!

The underhood portion of the bypass is very straightforward, actually. @cbarge did a really good tutorial on it, and bypassing the bulkhead connector. The underhood part doesn’t take all that long, just a matter of getting the right wire length and putting on the ring connectors. Once it’s ran with the other wires through the looms on the bulkhead and over the left wheel it practically looks like it came from the factory that way. Cheers!

 

[Ross Wooldridge]

In fact, I have been intending [the best of intentions!] to do a How To for the clutch relay. The only picture I currently have is the one above, but it's the diagram that you need to figure out your own routing/location for the relay and wiring. I'll explain what I did in more detail.

So, you've built a fire under my arse and I'll do a writeup with a schematic diagram in the next few days.

That would be most excellent!!

 

[rkrochen]

Ow! Yeah, the shoulder may be an inhibitor, to say the least. Hope everything went well and best wishes for a speedy recovery!

The underhood portion of the bypass is very straightforward, actually. @cbarge did a really good tutorial on it, and bypassing the bulkhead connector. The underhood part doesn’t take all that long, just a matter of getting the right wire length and putting on the ring connectors. Once it’s ran with the other wires through the looms on the bulkhead and over the left wheel it practically looks like it came from the factory that way. Cheers!

Thanks. Yes he did a great tutorial and I will follow it.

 

[Trace 300 Hurst]

That would be most excellent!!

It's easy, cheap ($5 relay at the Zone), and takes all those amps out of your bulkhead connector, ammeter, AC switch, and old wires.

 

[James Romano]

And putting my headlights on relays is on my “hit list”. I’m thinking the upgraded audio installation can also go on a relay, true?

I ran mine on a relay. I have a switch hidden in the ashtray that allows me to kill the system. I have a Blue tooth amp mounted under the package tray in the trunk, no head. I found that works best to keep the original look of the interior intact.

I also did the headlight relay upgrade and added a separate small fusebox to my radiator support that holds the fuses for the headlights, BT Amp, and Electric Fan. Looks better than 3 wired fuses hooked to the + side of the batt.

I haven't done the full firewall by-pass, only the 10 gauge to starter relay. Between that and the headlights, there was an immediate difference in the brightness and overall power of the car. You can tell it's happier. Current will always take the path of least resistance... so you can go bigger than 10, but definitely NOT smaller. It won't hurt anything if you use bigger wire.

I did replace my AMP gauge with a legit voltmeter. I was able to fit it into the original AMP gauge, and make it look totally stock. While you're there... consider replacing the crappy current limiter for the gauge cluster with a very good IVR3 or IVR4 depending on your car. That current limiter is another fire hazard with these cars.

 

[Newport 664door]

Thanks for the simple terms and pictures. Being color blind, my wiring diagram wasn't much help., my ammeter already had a meltdown, so this will solve the problem of what to do with the exposed red and black wires from ammeter?

 

[saylor]

I think we're talking about this 10AWG wire. Indeed, most other wires are 12 and 18. AND old!

View attachment 399835

View attachment 399832

View attachment 399833

i see your post and must offer an apology and I shouldnt make such broad statements.

just because my car may not have X, doesnt mean someone elses doesnt - especially when they arent even the same model.

Thanks!

- saylor

 

[Newport 664door]

So if my black and red already melted at my ammeter, I can connect them securely and run that bypass wire? Thanks for tips

 

[Ross Wooldridge]

Cut off the melted bits and install good quality ring connectors with heat shrink sleeves. Bolt them to one stud only on the ammeter connections.

 

[Newport 664door]

That's all I have left is 1 stud, the other snapped when I tried getting burned wire of. So tie them together to the 1 good stud, and I can also do the bypass to reduce the load then. ? Thanks

 

[James Romano]

That's all I have left is 1 stud, the other snapped when I tried getting burned wire of. So tie them together to the 1 good stud, and I can also do the bypass to reduce the load then. ? Thanks

Guys might scream at me for this...but you can use a bolt as well. Tighten the hell out of it and tape it up really well. I have mine like that now, but plan on soldeing them together in the near future