12v regulator

[arcturus]

As part of my preparations to convert the PV to 12v I have been given this regulator. Possibly from an Amazon or late PV? Any body recognize it.There seems to be a ground wire coming off the fixing plate. To battery? Also converting light bulbs. ie Instrument lights 2 watt. Same wattage?
Still waiting for carb' parts so I can on with PV.

[Ron Kwas]

Arcturus;

V Reg does look like the typical 12V Bosch (relay) type used in Amazons (or 544), however...I recommend against using it without verifying PN which I expect/hope can be found either on assembly or that yellow tag.

"...ground wire coming off the fixing plate. To battery?" ...negative return, yes to Battery (is quite important for V and I sensing) and is made through chassis mount in 122 installation (I would expect the same in 544, but don't know this for certain)...so this VReg may have come from another donor vehicle where a wire was used in factory installation, OR wire was added by a PO (paralleling up Bat negative connection can never hurt, but it is really NOT necessary and often a workaround for poor stock connections elsewhere...it's absolutely better and recommended to have clean and tight stock connections everywhere!!).

When changing V of system from 6V to 12V, general rule is to install lamps intended for the 12V service and keep Wattages of lamps the same. See also: https://www.sw-em.com/Vintage_Volvo_...conversion.htm

Cheers

[arcturus]

Thanks Ron. As soon as I get the PV up and running I intend to carry out the conversion. Didn't want to do it at this time in case I had issues with rebuild and didn't want to confuse the issue as to whether re build or re wire. Any way How would you say was the best way to connect up the DR's. I know that it should be in series to the wipers but that the two DRs used should be connected together in parallel. It's the physical connection of the two I'm interested in (connections will be soldered) between switch and wiper. Should they be wired that way after the switch or before it? I will be using two also for the blower motor.I purchased six. Are they to strong for the fuel gauge? Save me hunting for single 80ohm resistor.Don't really want to spend a day and drive 100k each way to look for a ten cent resistor

[Ron Kwas]

arcturus;

That certainly (still) looks like a VReg for Bosch Generator equipped Chg Sys, but others might verify that PN (or verify it in a parts or replacement parts list).

DRs can be wired anywhere in the current path to decrease Voltage on Load, the longer item is powered, the longer they produce heat, the hotter they get...so observe temperature safety and mount to a surface which can dissipate heat which they will produce...

DRs are not necessary for fuel gauge...but an 80Ohm resistor will fit nicely and almost flat into a letter envelope...I suggest you have someone send you one with a Birthday card!

Cheers

[arcturus]

Could you please post a quick sketch of circuit from switch through two DRls in parallel. Don't want to screw up.

[Ron Kwas]

https://www.sw-em.com/Vintage_Volvo_...ping_Resistors

[arcturus]

Thanks I have this but nor sure of the best way to include the second DLR.

[Ron Kwas]

A;

Resistors in Series > Resistance value is higher (values add, use this configuration if you need further decrease in motor speed/further voltage on load reduction).

R in Parallel > Resistance of two equal Rs in Par is half value of one. Use this if voltage drop with a single is too much (motor speed too low, etc)...three equal Rs in Par, one third...if R values are mixed Rtot = 1/R1 + 1/R2 + 1/R3 etc.

Cheers

[arcturus]

Re fuel gauge i have the offer of a 100 ohm resister from a local friend. Do you think that it will be OK?

[Ron Kwas]

a;

Sure...it's OK to try that value...as my tests found, the gauges are very tolerant of supply voltage variation, so I function will be fine...worst case, calibration might be off a bit, but nothing one wouldn't get used to, as you keep you eyes open for an 80 Ohm R...

Correction: Please note in my last posting, term on left side of equals sign must be 1/Rtot!

Cheers