Shop Man­ual

Street Rodder - - Contents -

Q I’ve re­placed the sin­gle elec­tric fan on my ’55 Chevy that was ac­ti­vated by a tog­gle switch with dual elec­tric fans that are con­trolled by a Dakota Dig­i­tal PAC-2750.

The car has Vin­tage Air and was equipped with a tri­nary switch with four con­nec­tions—two for low/high pres­sure and two to turn the fan on with the A/C on.

I’ve been told that I have to change the safety switch to the bi­nary type that just pro­tects the

A/C sys­tem be­cause the PAC-2750 op­er­ates the fan ac­cord­ing to en­gine tem­per­a­ture and when the A/C is turned on.

I’m hes­i­tant to change the switch be­cause that would mean drain­ing the A/C sys­tem and then recharg­ing it. Can I keep the switch I have, and if so, which wires do I use? H.Pertroski ViatheIn­ter­net A Ac­cord­ing to Scott

John­son of Dakota

Dig­i­tal, ei­ther a bi­nary or tri­nary switch will work with the PAC-2750. When us­ing a tri­nary switch only the high/ low pres­sure pro­tec­tion func­tion is re­quired, as the PAC-2750 will con­trol the fan(s) by tap­ping into the power con­nec­tion that feeds the com­pres­sor. That 12V sig­nal pro­vides a trig­ger en­gag­ing the fan(s). John­son added that be­cause the A/C ac­ti­va­tion func­tion of the PAC-2750 in­put is sim­ply look­ing for the pres­ence or ab­sence of power to the A/C com­pres­sor clutch that wire could be re­pur­posed as a fan over­ride switch for those with­out A/C.

John­son pro­vided the fol­low­ing wiring di­a­gram that shows the use of a tri­nary switch with the PAC-2750. Note the color of the wires to be used on that switch are both black with a green stripe. The other two wires are not used.

Tech, Trail­ers, and the Oc­ca­sional Wise Crack

Q I’ve been read­ing

STREET ROD­DER for over 20 years. I’ve fol­lowed the tech sto­ries faith­fully and used many of them to build cars over the years. I al­ways start at the back of the new is­sue. The first thing I read ev­ery month is your col­umn, then Ron Covell’s, then Brian Bren­nan’s ed­i­to­rial, then every­thing in-be­tween. It’s al­ways amus­ing when he takes a shot at you and you make a crack about him in a story.

A num­ber of years ago you did a story on build­ing an af­ford­able car trailer. I would like to copy what you did but have not been able to find the is­sue where it ap­peared. Can you tell me when that story was printed? C.R.Bond ViatheIn­ter­net A Thanks for stick­ing with us for all these years and giv­ing me the op­por­tu­nity to point out to Bren­nan that you start at the back of the book and work your way for­ward.

The trailer story was some time ago; it ap­peared in the July ’09 is­sue. While some­what of a de­par­ture from the tra­di­tional tech sto­ries, we fig­ured that many street rod­ders would be in­ter­ested in an af­ford­able car trailer that was easy to build. The only draw­back to own­ing your own trailer is all your friends who don’t have one will want to bor­row yours.

Our trailer used a sim­ple an­gle iron frame and wood deck­ing. We added a tool­box to hold tiedowns, a winch for load­ing non­run­ning projects and an elec­tric tongue jack to make life easy. The load­ing ramps were made from some dis­carded cat­walk found at a scrap yard; they’re stored in a re­cess in the deck. Load­ing and backup lights come in handy and cast­ers keep the tail from drag­ging on steep drive­ways.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.