HELP! Blower Fan only works on Low (1 Viewer)

[Rock40]

After spending some time looking through old threads I still can't find a clear answer to this problem. Please lend me some of your wisdom...

I have a 96' FJ80 and the climate controls (it does not have the auto climate feature) all work like they should with the exception of the blower motor. It only runs on the "low" setting no matter what fan speed button is pushed. It does turn on/off like it should and the blower motor connection (behind the glove box) is properly installed.

Is this something to do with one of the AC Amplifiers? Being an electrical system, it seems like this should be an "all or nothing" type of problem. I can't figure out how/why the unit has power but the fan speed won't increase.

Maybe I'm the only guy who's had/having this problem but I doubt it.

 

[Grim Reaper]

Blower motor speed is controlled by the switch and a resistor pack. 95 % of the time it's the resistor pack. Follow the wires out of the motor back and it will come from the resistor pack. Take it out and take a meter and measure the resistance across the different resistors you will see. If you find one open then that's confirming its bad. $30ish at most parts stores.

 

[Rock40]

OK, I will dig that out tomorrow morning and test it. I'll post some pics if that turns out to be the culprit here.

 

[Rock40]

I pulled out the resistor set which is held into the AC/blower ducting with two small screws. Looking at the terminals, it was obvious this had been wet at some point as the contacts were heavily corroded. Figuring I had nothing to lose, I used my media blaster to clean up the terminals before checking the internal resistance with a meter.

As far as I can tell, the unit tested fine electrically but cleaning the terminals did nothing to solve the issue. I'm going to replace this just to be on the safe side.

Someone mentioned that there may be a 2nd set of resistors/relay above the fan blower itself? Does anyone have any input on this part or what it looks like? Also, should I be pulling all the relays in the DS kickpanel to check for issues there?

 

[Rock40]

I also checked the relay (square plastic housing) in the DS kickpanel and that too appears to be working fine. It kicks over as soon as I activate one of the blower speed controls.

I also located the Blower Speed Control Relay which is nestled way up on top of the AC/Blower ducting. There also appears to be an additional relay (round relay, metal housing) which looks similar to the other relays found in the DS kickpanel.

As mentioned on the other threads, the Blower Speed Control Relay is a real PITA to access and it looks like I'm going to have to remove must of the AC/Blower ducting to get at it.

Hopefully I'm on the right track. If anyone has any suggestions please chime in.

 

[Rock40]

I opened up the glove box compartment in order to locate the Blower Speed Control Relay which is on top of all the ducting. It was a pain but I got the unit out in one piece. The electrical connections look fine; nothing burnt or corroded. I also removed an additional (metal housing) relay which I'm guessing is possibly the high speed control? On the earlier 80's this was apparently mounted behind the DS kickpanel. Again, the connections on that look fine.

If anyone is interested. Here's some photos of where to locate the Blower Speed Control Relay and what it looks like. The photos show the large, 8 prong plug up on top of the ducting and the connector for the other relay is directly to the left of it.

The Blower Speed Control Relay is Denso P/N 061700-2760 and the other relay is Toyota P/N 90987-03001

Based on the lack of response to this thread I'm guessing that very few others have experienced this problem. I'm currently waiting on a new blower resistor at this time.

One other thing, I metered out the 4 prong plug to the blower resister and I'm only getting 12V on one of the prongs. This doesn't change no matter what fan speed button is pushed. Does anyone know if this is normal? Are the other 3 wires feeding all the associated relays somehow?

 

[Aggiesdm]

Sorry for the overall lack of responses, but I've never dealt with anything like this. I am watching and learning. Keep hammering away and I'm sure you'll get it fixed. There are only a few things it could be.

Just a thought...do you have the climate control with the electrical buttons or are they the older sliding levers? If its the buttons, could it be something with the control board? Just a thought. I have levers, so was just wondering...

 

[NLXTACY]

Sorry for the overall lack of responses, but I've never dealt with anything like this. I am watching and learning. Keep hammering away and I'm sure you'll get it fixed.

Ditto over here.

Someones got to be the trailblazer

 

[Rock40]

Yeah, this electrical stuff can just get really frustrating. I'm used to working on my 69' FJ40 and it seems a bit overkill to have a heater/blower system with multiple switches/relays/resistors. Maybe I'm just old fashioned.

I will add that the relays above the ducting are not "clicking" or doing anything when I activate the fan buttons. The single relay in the DS kickpanel is however.

The climate control panel is all buttons with the exception of the hot/cold mix. I have not metered it out yet but all the fan buttons light up appropriately when pushed. All the other controls work also. Has anyone had one of these control panels fail? I know they're not cheap.

Here's a pic of the panel

 

[TAOTAOMOTNA]

Finally someone w/similar problem. My blower will not blow at all I tested the blower, resister and the 2760 relay. The only thing I noticed is every thing works but relay was jumpered and then blower worked but don't try it ,sadly none on Island so have to wait to get one but in my testing it's the 2760 relay I burnt a fuse while testing. Does anyone have a 2760 relay out there unfortunately Lc on Guam are like Dinosaurs. need parts Guam is hot. 99 F 99 Humidity Hot.

 

[Rock40]

So I take it you fried it doing this or a PO had hacked it up? I'd try looking around on EBAY for a replacement or try to contact a Toyota dealer on the mainland and see if they'll ship you one.

I'm not certain that the speed control issue is the culprit yet but I haven't eliminated it either. I don't have an electrical diagram/manual which is making this much harder. Hopefully I'll know more next week

 

[Rock40]

It helps if everything is plugged in........

I bought this truck with no engine/transmission/transfer case for a 1HD-T swap. I'm doing a bunch of maintenance/repairs/etc while I wait for the turbo diesel to show up.

Anyway, I found another electrical plug up behind the glove box door which was unplugged; probably when the computer was taken out (of which I had no part). After receiving a new OEM resistor and a replacement Fan Speed Control Relay in the mail today, I realized (to my embarrassment) that the above mentioned plug was apart. After plugging it in, everything worked perfect and there was nothing wrong with the old components. That actually made sense since the original fan resistor tested fine.

I almost hate posted this because "fixing" this should have been really easy and I made a much bigger deal out of it than it should have been. Hopefully, someone will who is looking for that darn Fan Speed Control Relay will find this posting useful.

Check the obvious first

 

[Aggiesdm]

Hey man, don't beat yourself up. I would be happy as a butcher's dog if I had a free fix!! Congrats.

 

[97LandCruser]

great info. i just found this same problem in my 97 today. low sped no matter what setting. also i also bought my 97 with blown engine. and i put 5.3 v8 in it. soi will check plugs too as the ecu was unplugged and other things unplugged from PO having the engine pulled.

 

[Francis J.]

Rock40 thanks for the posts! I am in process now. My black plastic fan control is almost directly behind the vertical upright that is attached to the grey AC box. I can reach in and feel the outline but how to slide it off/out remains to be felt!

 

[Rock40]

It does slide on and off but it's tight and nearly impossible to get out with the AC condenser installed.

 

[Madcrix12]

so i have a similar problem... except i have no blower. i have tested blower and all is well. was workign fine then came back to van 30 mins later and intermitant fan to no fan now

i have pulled the blower clontrol relay and tested the relay as per workshop manual and i figure its blown. it clicks on, but there is no output. any idea on how to jumper it so test?

 

[808keith]

Something similar for me except no first low setting. All other fan settings work fine.

 

[Madcrix12]

That's a blower resistor. Mine turned out to be the power wire to the right hand side 3 fuse, fuse box.