Click on image for the lowdown. 
====
| | | Forums66 Topics128,040 Posts1,055,478 Members48,424 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jul 2005 Posts: 153 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2005 Posts: 153 | What should the draw be on a 61 blower motor. I have found that if I leave my blower motor I cant start my truck. The voltage gauge reads about 13 but when I energize the key with the fan motor on, the volts drop all the way down to 9. If I shut the fan off the volts come right up and the truck fires. I'm pulling the blower motor tomorrow to check it out but I figured I'd ask first. | | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | handymanmac,
I would skip the blower motor and go straight to "battery". A good battery has hundreds of cranking amps available and that little blower motor draws less then 4 amps (12 volts)....if that makes the difference between go and no-go, something is really rotten in Jersey!
Stuart
| | | | | Joined: Jul 2005 Posts: 153 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2005 Posts: 153 | I have a brand new red top optima in the truck. The only way I can get the voltage to drop is from the blower motor being turned on.
What else could it be?
Mac | | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | handymanmac,
It sounds like you have a bad connection between the battery and the system. Are the cables clean and tight? The point is, if the little blower motor is making the difference between having enough oink to start or not to start, something is terribly wrong.
A current draw meter should show no more than 250 amps (approx) with your new battery...if it exceeds that, the starter is working much too hard to crank the engine over. This means a bum starter or a binding of some sort in the engine itself.
Your blower motor mystery is actually an indicator of a problem somewhere else....I think!
Stuart | | | | | Joined: Jul 2005 Posts: 153 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2005 Posts: 153 | Stuart your right about being an indicator of something else. I started going through everything last night and will continue this morning. As for the battery, cables and starter they are all new. I suspect there is a wiring issue somewhere possible even in the "new" parts. I am getting a voltage drop on a few things so I'll start searching for the gremlins.
I'm glad I enjoy do this stuff, plus the inlaws will be over today!! Off to the garage!
Mac | | | | | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | Mac,
Your post indicates your truck probably has a key start starter. Battery power is supplied to the starter motor by internal switches that are "made" when the solenoid is pulled in.
The wiring from BATT to starter would affect the ability of the starter to turn, while a problem with the smaller, interior wiring could make it difficult for the solenoid to pull in and spin the starter.
I'm not clear which of these problems you have...with the fan motor on, the starter pulls in but won't turn, or, the key won't even pull the solenoid in.
As I mentioned earlier, the little blower fan would have to pull a horrendous amount of current to draw the battery down to where it wouldn't start the rig...fuses would blow and wires would melt! This is a very unlikely scenario. Good luck, and don't you just love those in-laws.
Stuart | | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | Your heater & acessories should be wired to the acess. side of the switch. When you go to the start possition it turns them off. Stuart is right, you are loosing voltage somewhere. Check the connections on the back of the ign. switch & the bulkhead plugins.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | When you have the blower motor on and there is a big voltage drop, something will get pretty warm, where ever the drop is happening. If it is in the ignition switch, you can probably feel it in the back of the switch but DON'T try feeling it with rings on your finger because you could cause a short and burn your fingers. You should also check the voltage coming into the switch and going out of the switch when the blower is running. | | | | | Joined: Jul 2005 Posts: 153 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2005 Posts: 153 | UPDATE!
I narrowed it down to the ignition switch. I replaced the stock switch with a flaming river ignition and it solved the problem. This trucks wiring is a mess to say the least. I cleaned up a lot of it and while I was under the dash I wired in a relay and door jamb switches to operate the dome lights. I have a painless harness to install but I wont be doing that for a while. I hope this works until then.
Mac | | | | | Joined: Jul 2006 Posts: 327 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2006 Posts: 327 | Stuart and fred you've done it again you know everything What the H... is a flaming river ignition.... Cousin Peter happy new year... | | | | | Joined: Jul 2005 Posts: 153 Wrench Fetcher | | Wrench Fetcher Joined: Jul 2005 Posts: 153 | I have a flaming river steering column and they also make an ignition switch for custom applications. i got onewith my column so I wired it in.
Mac | | |
|
|
