window motor - rewiring with relays

[rsporsche]

in an effort to speed up my windows, following up on the excellent posts by Stevehose, Jmackro + DeQuincey on this subject ... i have already regreased my rear windows and gearboxes and am now ready to provide cleaner power to all of the motors (i will clean + regrease my front regulators + gearboxes while i do the rewiring. to better understand the wiring, i have put it into the format of the enlarged 2800cs wiring diagram for comfort equipment in the blue books. the wiring for a 3.0cs might be slightly different (i haven't looked)

i will be using hella 965400001 SPST (4 pin relays) - 3.77 each from summit racing, mounted in hella h84989011 sockets. 1.11 each from summit racing. I will be using 12 ga wire from the battery to the 30 pin side of the relays and 14 ga wire from the relays to the motors. i will leave the existing wire to the switches as little power will flow down those wires. i will leave the wiring between the motors and the terminal connectors - all rewiring will be done on the switch side of the terminals.

if you see anything that looks wrong with this wiring approach, please let me know. any other advice is also welcomed. otherwise i will keep you posted on the success achieved.

 

[teahead]

Looks good to me, but I dunno; I'll be using 2-wire E28 motors in my rig here soon. I should add relays too.

 

[rsporsche]

i thought about it but don't you have to modify the 2800cs regulators to do it? what's involved? i remember that the '74 regulators were very easy with the e28 motors.

 

[HB Chris]

Kurt Delimon did a great write-up on early regulators, just one small mod needed. Later cars are plug and play.

 

[rsporsche]

thanks Chris ... i will look it up and if i don't get satisfactory results i will give it a whirl.

 

[HB Chris]

I couldn't find it, send a PM to kurtd.

 

[rsporsche]

found it
http://www.e9coupe.com/forum/threads/replacing-rear-window-motors-how-to.1696/#post-9088

 

[rsporsche]

for anybody that wants the procedure for e28 motors mounted on early front regulators - send me a PM, with your email address, and i will send you a MS Word doc with all of the text + pictures.

now i will look for the procedure of how to do this with early rear window regulators.

 

[jmackro]

i thought about it but don't you have to modify the 2800cs regulators to do it? what's involved? i remember that the '74 regulators were very easy with the e28 motors.

"part 1" of the procedure is at: https://sites.google.com/site/kdelimon/windowmotorconversion1 and there is a link at the bottom to part 2.

Yes, for a pre-Feb/Mar 1973 coupe, some drilling and cutting is required.

I'll be using 2-wire E28 motors in my rig here soon. I should add relays too.

You really have to add relays when switching to the E28 motors, as they are wired quite differently from the original e9 motors. e9 motors have 3 wires, e28's have two. Part 2 of the procedure provides a schematic for the relays.

 

[rsporsche]

yes Jay, i found that too, i have the removal of the regulator, part 1 and part 2 of KurtD's process put into a single MS Word doc. the drilling and cutting for a pre '74 is identified in this detail. hopefully i can find what is involved with doing this for the rear regulators.

i would think that the wiring for the relays of these motors is very similar to my diagram below, but if its a 2 wire motor ... how the ground works is a little different ... but that is shown in the wiring schematic on Kurt's page.

 

[HB Chris]

"part 1" of the procedure is at: https://sites.google.com/site/kdelimon/windowmotorconversion1 and there is a link at the bottom to part 2.

Yes, for a pre-1974 coupe, some drilling and cutting is required.


You really have to add relays when switching to the E28 motors, as they are wired quite differently from the original e9 motors. e9 motors have 3 wires, e28's have two. Part 2 of the procedure provides a schematic for the relays.

No drilling or cutting required as of Feb/Mar 1973 when coupes got the newer motors, switches, regulators and circuit breakers.

 

[jmackro]

No drilling or cutting required as of Feb/Mar 1973 when coupes got the newer motors, switches, regulators and circuit breakers.

Chris: Thanks for the clarification - I have edited my post#9. My 2800 CS is a 1970 so I don't know much about those new-fangled cars. Did Feb/Mar 1973 and later e9's use the same motors as the e28's?

i would think that the wiring for the relays of these motors is very similar to my diagram below, but if its a 2 wire motor ... how the ground works is a little different ... but that is shown in the wiring schematic on Kurt's page.

I'm having trouble getting my mind around your schematic in post #1, so I can't confirm how it would differ for a 2-wire motor. Note that the schematic on Kurt's site (reproduced below) explains how to wire the e28 motors directly to the switches without using relays, though I would certainly recommend adding relays. Note that while you can use single-throw relays for the early e9 3-wire motors, you'll need double-throw relays for the 2-wire e28 motors.

 

[HB Chris]

Jay, they sure look the same

 

[rsporsche]

I'm having trouble getting my mind around your schematic in post #1, so I can't confirm how it would differ for a 2-wire motor. Note that the schematic on Kurt's site (reproduced below) explains how to wire the e28 motors directly to the switches without using relays, though I would certainly recommend adding relays. Note that while you can use single-throw relays for the early e9 3-wire motors, you'll need double-throw relays for the 2-wire e28 motors.

Jay, keep in mind that my schematic in post 1 is based on stock sardine motors - this was a cleaned up version of what you, Steve + deQ drew ... only difference is, its for both front and rear windows ... and i didn't use with the diode. i looked at the diode and resistor relay ... but they didn't connect the same circuits that you + deQ did. the hella relays put a diode between 86 (switch input) + 85 (ground) ... your schematic was between 85 (ground) + 87 (output). please help me understand what the diode does here? remember, i'm electrically challenged.

 

[jmackro]

Jay, keep in mind that my schematic in post 1 is based on stock sardine motors

Yes, I had understood that. It's just that the day-glow wires on a black background are hard for me to read.

please help me understand what the diode does here? remember, i'm electrically challenged.

Actually, the labeling on the wiring diagram you reproduced in post #14 provides a basic answer: it notes that they "clamp kick back". This means they suppress arcing across the relay contacts when the motor is shut off and the still-turning motor acts as a generator. There's more detail about this at: https://en.wikipedia.org/wiki/Counter-electromotive_force

Honestly, if you leave the diodes out, your relays will still probably last for the rest of your life. On the other hand, if you include them, the relays may last twice that long.

the hella relays put a diode between 86 (switch input) + 85 (ground)

Diodes there won't do any harm, but won't do much good on an E9 window circuit either. The relay coil has so little inductance that the arcing it will induce in the window switches is trivial. However, if you were switching those relays with small transistors (which are very voltage sensitive), diodes would be necessary at those locations.

your schematic was between 85 (ground) + 87 (output)

Yes, that's where you want them for this application. Note that polarity is very important.

 

[rsporsche]

Actually, the labeling on the wiring diagram you reproduced in post #14 provides a basic answer: it notes that they "clamp kick back". This means they suppress arcing across the relay contacts when the motor is shut off and the still-turning motor acts as a generator. There's more detail about this at: https://en.wikipedia.org/wiki/Counter-electromotive_force

Honestly, if you leave the diodes out, your relays will still probably last for the rest of your life. But if you include them, the relays will last twice that long.

thanks Jay, I appreciate the information for learning. sorry about the day-glow colors. i tried printing them from autocad, and things didn't show up to well as the black background turned white ... and the colors didn't work. next time i will try thinning the lines down and tweaking the colors.