Carledo wrote: ↑Thu Jan 21, 2021 3:16 pm
My wiring diagram (>VA15000) shows the HRW having it's own dedicated terminal on the fusebox, 1 of 5 green leads so connected. My memory tells me that of those 5 greens, 2 are siamesed together on a single tag and the other 3 are singletons, however I can't say for sure WHICH 2 are siamesed, I THINK its the VS feed and rev counter/voltmeter feed but could be wrong. However it works though, the HRW is DEFINITELY fed from the fused ign live on ALL models. If you want to fit a relay (and I have no quarrel with THAT, i've done it myself) i'd keep the switching feed ign live and power the relay from a permanent source.
Dunno about the hot air blower rear demist, it's an interesting concept and may well clear the window more efficiently than the original heater element. But it will involve some unsightly plumbing and the matter of current draw, big wiring and possible bigger alternator requirement make, IMO, a good used window a more practical and cost effective proposition. A toughened HRW is a lot easier to fit (and less potentially disastrous if you get it wrong) than a laminated front screen! I recently fitted both rear AND front screens to a Sprint in less than 1/2 an hour (empty shell after colour change respray and new vinyl/headliner) and had them sealed in and mouldings in place in not much more than another 30 mins. On my own!
Steve
It was that the connection was moved from the switched to the unswitched side of the fusebox at some time - could have been me even. But there's only two green wires on that one Lucar connector. I think the other one is the reverse light switch supply. So had I parked it in reverse and did the reverse light actually work, I could have drained the battery that way.
I've got to look again at the vent holes in the back shelf. If memory serves, the two outboard rectangularish holes under the cover have the magnets of the subs hanging through them (I don't care that they share an infinite baffle - they're only subs), but the inboard sort of half trapezoidal, wider at the back ones are free and, I think, nicely placed for a pair of vents. So if the tubing's the right size to fit, I might get the old Herald vents mostly in those holes, and they'll hardly show - might need a bit of MDF as an escutcheon round them, covered in that sicky backed leather effect vinyl. So then the wiring, heater box, and pipework will all be in the top front of the boot, out of sight and reasonably out the way of the shopping. If the current draw really is a problem, I'll have to look at a switched mode DC-DC converter for the heater supply to limit the draw - leaving the fans on the full 12. But they're only a few quid and 3 weeks from China. But I'm not expecting it to be an issue, if I guess what they mean by 500 Watts on ebay - I'm betting on under 150 actual Watts at 12-14V if it's 500W at 24-28V (on a downhill slope with a following wind). But it does depend on the thermal co-efficient of resistivity of the element, and its two temperatures (by proportion in K, not C) (fan's going twice as fast too), so it's only a guess pro temps .
The back window was recently out to replace the rubber (and for an insurance job respray of the front end), which was in a bad way at the bottom nearside corner. I guess that's when I should've done it. But I didn't. I might still think about it if I can re-use the newish rear screen rubber and I can get a cheap screen delivered to the soggy bottom (left-hand corner of the Kingdom of Jorvik) that is the Fylde. But since I've got the heater box on order, and the wiring mostly in place, I think I might have a go at the venting and such - assuming there's a dry-spell in West Lancs.
Graham
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.
Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
