BritishV8 Forum

there is an annual car show in San Martin, California called food truck fly-in. it is at a local airport and I made it there with the TR6 today. here are some pictures for those of you who a long time ago thought I should show you some

Scott, Are you using the original fuse block or newer aftermarket? The original is known to get bad connections.

The fuses in the fuse block appear fine. But there's no power to the fuse block. A bad ground possibly? Theres 12.5 V at the starter and the power wires to the MSD box. After changing the fuse I expected it to blow again but it hasn't. But no power to the car accessories, ignition switch, everything. Except there is power to the starter and MSD box. ? I may have to get a real mechanic to figure this out. Car electronics issues are another specialty I have almost 0% chance of diagnosing. Internet don't fail me now!

With the engine fitted (hopefully for the last time) I fitted the alternator, EWP and air con compressor on the front of the engine today.

I have realised that four months have gone by and I haven't updated this journal but here goes. Since the last post I found that the sump gasket that was supposed to be fitted dry was weeping oil, with the RX8 gearbox adapter plate I  had to remove the and split the engine from the gearbox before I could remove the sump. I also found that the starter pinion was too close to the flywheel so a thin spacer 1/20" had to be made and fitted. It's back in now for what I hope is the last time. I have fitted the plate in front of the engine that carries the alternator, air con compressor and EWP, I didn't find a means of fitting an automatic tensioner so it has to be done manually. At the back left you can see an engine steady bar, I need this due to a couple of factors, firstly the engine mounts are a little low down on the engine and all of the clearances are tight. I have a 1/2" or less clearance between the cylinder heads and firewall cut outs, the headers, alternator and air con compressor are equally close to  the chassis rails. You can see a UJ fitted to the shortened pinion shaft on the steering rack, this was needed to to lower the shaft by about 2" where it passes through the bulkhead, this was done for header clearance. The EPAS has a double jointed  telescoping section at the bottom which is the exact length to fit onto the new pinion shaft.
I have just done a trial fit of the radiator and cooling fan, the Chinese made radiator is for a late model MGB. I had to cut the outlet spigot off and weld a tight elbow due to insufficient clearance between the radiator and the steering rack. The fan is a 14" puller fan from SPAL.   Although it looks to be touching there is 3/8" clearnce between the fan and the air con compressor.

There seems to be some built in protection and the major components do have ATO/ATC type fuses built in whereas the vintage Marantz SA-247 EQ uses a glass inline fuse and I placed glass inline fuses in the tweeter leads. I doubt any of these draw enough current for a breaker to be suitable. I do have one breaker in the car but it is manual reset only and is a big-un. I agree glass fuses are old tech but sometimes they do have their uses and they are compact and simple. In a protected environment they can work pretty well. Under the hood, not so great. Better solutions are coming, refer to the gas sealed ATC fuse holders in Toyota's halogen headlight retrofit kit.

After much adoo I have sound. This required significant power and speaker lead rewiring and testing and the next part is clean-up and configuring the XS-5513 head unit for bluetooth plus adjusting the bias on the Mini 1969 TIP41C impedance matching boards and checking the heat sink temps. As class A devices they do get quite warm. In the event I don't like those I have a PAC LD10 Line Driver on order. I will see how things go with the bias adjustments. I'm looking for a reading under 185F on the IR gun.

So far the sound quality is quite good but it could use a bit more volume. The EQ's fader control could use a bit more authority but perhaps I have a bit more adjustment on the front amp's level that can help with that. I hope to get that all sorted today and get the center console back in place. Then Tunes to the Moon!

Jim

I don't have anything to say about protecting speakers specifically. But you mentioned wiring and circuit protection back on Sept 1, and that's my former area of expertise. Maybe these general tips will help someone. 

When I was on the electrical engineering team of a major commerial truck OEM, my colleagues and I avoided:
(a) use of glass fuses for anything at all. Obsolete technology. (And that was >25 years ago.) 
(b) SAE Type 1 automatic circuit breakers. When we were obiged to use circuit breakers, we used SAE Type 2 "modified reset" breakers exclusively. The difference is that T1 breakers will cycle on/off indefinitely by themselves whereas T2 breakers will latch in the open position until the driver cycles the power supply to "off". In some circuits T1 breaker contacts are prone to welding themselves shut, which may leave you unprotected and result in a thermal event. (If you're looking at decent quality automotive parts, breakers will be labeled "T1" or "T2".)
(c) using a remote circuit protection device to protect a device. Fuses and relays are very good for protecting wiring. If a device needs to be protected, that protection should be built-in. If the device doesn't have adequate built-in protection, use a different device. And btw this doesn't just apply to over-current. It applies generally to reverse polarity, RFI/EFI interference, etc.

For my own projects, I try pretty hard to avoid inline fuse holders. Too hard to find quality components or to integrate them in a tidy way. Tidy is important.  

I have the system installed finally and have started setting it up, learning a few things along the way. First that my power circuitry was flawed, which I had only partially fixed by modding the EQ turn on circuit. I had issues with the external turn on wiring (remember the speaker fire?) and had to replace the light blue wire to the rear as well as re-route the power (ACC) wire to the head unit as it was tied into the green circuit, as was main power for the rear amp so neither one was turning on in the ACC position, or switching on the EQ or main amp. I removed the power and ground leads from the console to the trunk and will power the rear amp from the main power terminals I had installed on the bulkhead. That is also a handy battery charger connection spot. That should resolve the turn on issues. Along the way I've corrected a few wiring color issues.

Next is a feedback loop causing an audio tone in the system. I had dealt with the isolated (floating) ground in the connection from the head unit to the EQ as well as the impedance mismatch with isolator circuits (and I have a alternate isolator on the way in case this one is not good enough, they are cheap, around $20 or less) but neglected to deal with the exact same issue on the main amps. I overlooked it because those amps have an input gain control. But if you use the RCA inputs rather than the 4 pin connectors the shield side is grounded. That's fine for the inputs but not so great for the EQ's floating speaker output circuits.

So I now have to re-terminate the wires at the 4 pin connectors and hope it didn't fry anything in the EQ. My hopes are high since the system was wired this way before I tested the EQ on the bench. I think it should be OK. G assures me that the gain pot will also work on the speaker level inputs, which should allow me to balance the front and rear speakers.

So lots more testing and adjusting ahead. I'll use the signal generator to adjust levels at all 4 speakers once I have a clear no input status, do the same with the signal at the EQ inputs and then the impedance balancer inputs where I can also adjust levels to left and right, then move on to the head unit and bluetooth. At least the end is visible, if not all that close.

It'll be nice to get the console back in place finally so I can drive the car a bit and charge the AC system.

Jim

We might want to make this a sticky thread if there is adequate contribution. Anyway, lots of info we can put here and you have to start somewhere. So as a preamble, the state of modern automotive wiring has advanced a bit since the 60's and we can take advantage of those advances. So first a few general considerations:

Oxygen is the enemy of wiring conductors. Anything you can do to keep it out is going to improve reliability. As a general principle we could hardly ask for a better one and it applies to any conductor, anywhere and for any purpose, external or internal.

All connections are potential failure points (PFP). Any transition in a conductor is a PFP. Any change in conductor type, material, cross section or area is a PFP. Any change in insulation is also a PFP, as is any recognized failure of the conductor itself. So we see for example that a common one conductor bullet connector has at minimum 7 and really 8 PFPs. 2 insulation transitions, 1 spring connection (subject to breakage at 2 points), 2 solder or crimp joints, and 2 friction/spring joints. Oxygen increases the chance of failure at most or all of these PFPs. Even a crimped and/or soldered gas sealed connector has 3 PFPs but that is a marked improvement especially when the O2 is kept out.

Towards that end, adhesive and heat shrink sealed connectors are highly recommended as well as cross linked insulation on the wires because it is tougher and lasts longer. Gas sealed connectors are a good choice any place that they can be used. Wherever a conductor is exposed, a thin coating of silicone sealant of some type will help reliability. Probably our greatest challenge here is with switches and we are limited in our options but in many cases upgrades are possible.

Bullet connectors *can* be used but are prone to failure. This can be helped with silicone sleeves and a good anti-corrosive but be advised that dielectric grease does not have any anti-corrosive properties and is really no better than vasoline for this purpose. GuAl Gel is one popular product, there are others.

If you find you have a need to substitute wires, and let's face it there always seems to be a reason why we can't use the right colored wire, be it aftermarket additions or whatever, it's a good idea to think about which end of the wire is likely to get attention in the event of a wiring issue. That's the end you'll be trying to identify so it should be as consistent with the vehicle wiring as you can get it. For instance you might have a blue wire from a noise filter powering your sound system and be tempted to use a blue/w or blue/r wire to lengthen it but those colors are for the headlights, so later troubleshooting could get very confusing very fast. OEM radio feed is w/g and then w/p so a better choice would be white (even though that is for ignition) if you had to use a solid color, or at least something distinctly different from standard vehicle wiring. Sometimes we do have to compromise. That way you'd at least be looking in the right area at a small circuit rather than wondering why your seat belt wires are connected to your radio.

If you have additional suggestions please contribute.

Jim

I got the fuse replaced and determined the blown fuse is labeled MSD. So I turned the batt shutoff to on and the fuse did not blow but still no power to the car, nothing lights up. I checked the power supply to the MSD box and it shows 12.55 v. I haven't checked the main fuses yet; that's next. It seems the fuse panel lost voltage or ground, we'll see.